Bob is a service technician who is well trained and nationally certified. However, he sometimes suffers from the same confusion that all technicians occasionally do — the facts that he gathers may or may not point to the obvious cause of the problem or the best solution. But Bob has something that no one else has. He recalls his long-time HVACR mentor and imagines him accompanying him as “Btu Buddy,” someone who reminds him to take time to stop and think before rushing to judgment, helping keep him on the right track, even with facts that are confusing.
Bob was called to a new customer’s home that had a 5-ton heat pump. The home was a large ranch style home, all on one floor. The customer met Bob at the door and she explained to him that her power bills were considerably higher than the same months last year. Bob looked at the comparison and agreed. The seasons were similar, but the bills for this year were much higher.
Bob then went to the indoor air handler under the house and looked at the filter. All seemed normal with them.
He then went to the outside unit and looked around and nothing stood out to be a problem. He then went inside and checked the outlet temperature at one of the room registers. The temperature was 120°F. He then went to the room thermostat and checked the thermostat to see if the strip heat was calling for heat and it was not. He was looking confused when Btu Buddy appeared and asked, “What is the problem, Bob?”
Enlarge this picture
Figure 1. This electric heat element is grounded to the frame of the furnace causing it to produce heat all of the time.
Bob explained what he knew and asked Btu Buddy for some advice.
Btu Buddy said, “Check for amp draw at the strip heaters on both lines going to the heaters. Remember the time you had a strip heater that was grounded and it was drawing current all the time (Figure 1)?”
Bob got his ammeter from the truck and went under the house and checked all three strip heaters and there was no current flow. Bob then asked, “Now what?”
Btu Buddy then said, “You have ruled out heat from any source except the heat pump refrigerant cycle, so the excess heat must be coming from the heat pump coil itself. With an air discharge temperature like you are getting, I would suggest that you have a reduced airflow. A heat pump should not have a discharge temperature above about 105° and this one is running 120°. Feel the liquid line and tell me if it feels normal.”
Bob put his hand on the liquid line and exclaimed, “Boy, that line is really hot. Normally it would be about hand temperature, but that could burn you if you held it for long.”
“What does that tell you, Bob?” asked Btu Buddy.
“It tells me that the air stream is not taking the heat out of the refrigerant condenser coil, which is the indoor coil in the heat cycle,” said Bob.
Btu Buddy then asked, “What could be some reasons for these symptoms?”
Bob answered, “The filter could be stopped up, the coil could be dirty, the fan may not be moving enough air, trash in the ductwork, insulation may have come loose and dropped down, supply registers or return grilles may be restricted are possibilities (Figure 2). The duct is insulated on the outside, so there shouldn’t be any insulation on the inside that could be loose and cause a restriction.”
Btu Buddy then said, “Then you must eliminate those possibilities one at the time. It may be a combination of several of those things.”
Bob said, “I never thought of it being more than one thing. Most all of the trouble calls that I have worked on get back to one problem.”
Btu Buddy said, “That is usually the case. Let’s go do some checking. The simplest things to check would be the supply registers and return air grilles. I noticed that this house has multiple returns, so be sure to check them all.”
Bob went from room to room and checked the airflow possibilities and told Btu Buddy, “I found several rooms that both the supply and return fixtures were shut off. I talked to the homeowner and she said she was trying to save money by not heating those rooms. I explained to her that closing those fixtures was at least part of the problem.”
Btu Buddy said, “Now check the liquid line temperature.”
Bob held the liquid line and said, “That is much better. I think I will check the temperature with my thermistor temperature tester.”
After the check, Bob said, “The temperature is still 107°. I am not sure that we have gotten to the bottom of this problem.”
Btu Buddy then said, “Good point, check further.”
Bob looked at the fan wheel and commented, “The fan wheel has a lot of dirt in the curves of the wheel. I think I will clean the wheel.”
“Good point, Bob”, said Btu Buddy. “If the fan wheel is dirty, where did the dirt come from?”
Bob responded, “It had to come through the filters. At some point the filters must have been really dirty and let dirt pass.”
Btu Buddy then said, “Most filters only get the larger particles of dirt; much of the fine dirt slips through. In the summer, the coil is wet and acts as a super filter. I would suspect that the coil is dirty also.”
Bob got set up and cleaned the fan wheel and the coil, and said, “I can’t believe how much dirt came out of the core of that coil. It is a good thing I had this pressure washer. It just kept pushing out dirt. That especially made detergent for coils really did the trick.”
When Bob got the system back together, he started the unit up and after it had run for about 20 minutes, he looked at the temperature of the liquid line and said, “The temperature is down to 100°. That works for me.”
Btu Buddy suggested, “Bob, you need to check the outlet air temperature now that you have made these changes.”
Bob went in the house and checked the air temperature at the same place he had checked before and the temperature was 100°.
Bob went back outside with Btu Buddy and told him the results and Btu Buddy said, “Now you have confidence that you got to the complete bottom of the situation. Be sure and talk to the homeowner and tell her what you did. Be sure and mention the outlet air temperatures will be lower, but that the system will be more efficient.”
Bob asked, “Why didn’t you suggest that we put gauges on the system and check the pressures?”
Btu Buddy explained, “You could have connected your gauges. However, we came to the same conclusions without installing gauges. Remember, every time you fasten your gauges, you let out some refrigerant. The system has a critical charge and you may alter the charge when connecting the gauges. Also, you always have the possibility of leaving a leak behind and then you would be called back to the same job later to add refrigerant.”
Bob then said, “None of that would be good.”
Bob talked to the homeowner and explained everything to her and she understood to leave all airflows alone.
When riding away, Bob asked Btu Buddy why high head pressure resulted in such a dramatic change in power consumption in a heat pump and Btu Buddy said, “Let’s go to lunch and talk about it. Bring your text book so we can discuss some examples.”
Saturday, March 1, 2008
Some typical Q & A
AC unit for 450 sqft clip this post email this post what is this?
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Posted by nickt (My Page) on Fri, Feb 29, 08 at 15:02
We are being told that the smallest AC units available are 1.5 ton. But, we only have 450 sq ft to cool (bedroom, bathroom closet suite w/ 9 ft ceilings and an office with a 11 ft vaulted ceiling). Would a 1.5 unit (placed in the attic space) be grossly inefficient? Can you use strategic placement of the thermostat to try to get more dehumidification and prevent short cycling? Can you just blow the extra air out an attic vent or something?
We have looked into mini-splits and are concerned that a single unit would not be able to cool all four spaces effectively. Multiple units would just be overkill.
Any advice would be greatly appreciated.
--------------------------------------------------------------------------------
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RE: AC unit for 450 sqft clip this post email this post what is this?
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Posted by mikenew (My Page) on Sat, Mar 1, 08 at 8:19
It's hard for me to believe you can get all that in 450 sqft. there are multi zone mini splits that may help in this application, otherwise you can bring in some outside air and condition it to offset the oversizing
Frigidaire vs Lennox gas furnace clip this post email this post what is this?
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Posted by lynnt (My Page) on Fri, Feb 29, 08 at 21:48
I live in the Washington DC area, in a 50-year-old 2300-sq-foot rambler. A service rep from my HVAC company shut down my 20-year-old Kenmore 80 1000-btu gas furnace this afternoon. He had run a camera on a cable up the burner flues into the heat exchanger, and showed me what he said were cracks: lighter lines among the black soot and more than a bit of rust. Although the monoxide alarms around the house and in the furnace room have not complained, he said the furnace was unsafe and must be replaced immediately.
OK, I can buy that the poor thing is at end of life. Question #1, do you agree that it had to be shut down immediately, or is this a pressure sales tactic? He didn't cut any wires, just turned off the breaker and the thermostat; is it safe for me to turn it back on?
Question #2, the sales rep is offering the following replacements, all 1000-btu Frigidaires (which I understand are made by Nordyne). What do you think of these furnaces, and does the price sound reasonable? They include running the required new exhaust PVC for the 93%er, plus all include $350 for running about 20 feet of flexible ducting to a badly-served dining-room addition.
80% 2-stage FG6TA096C12B $3500
80% 2-stage variable FG6RA096CVBA $4410
93% 2-stage FG6TC080CVBB $4550
The same company will replace my aged gas hot-water heater with a new 50-gal model for about $900, and add a system humidifier for about $650 if I do these at the same time as the furnace work. Comments?
Another company prefers Lennox furnaces; they say all I need is a 90K BTU furnace due to the increased efficiency these days -- though the old furnace was sized before the dining-room addition was built. They say the 80% Lennoxes are sturdy and far more reliable than the fancy Energy Star models. They are proposing:
80% G40 $2300
90% G51V $3400
and will do my hot-water heater for $625 along with the furnace replacement.
Is this apples and oranges? I really appreciate your input, and apologize for the long writeup. Both companies have good records in the area, and both have been around for more than a decade.
Lynn
--------------------------------------------------------------------------------
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RE: Frigidaire vs Lennox gas furnace clip this post email this post what is this?
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Posted by ryanhughes (My Page) on Fri, Feb 29, 08 at 22:56
The Lennox prices sound a bit low. Make sure you know what you're getting. Get all of it in writing: parts, materials, warranty, permit, etc. etc. Both brands are fine in my opinion. You really aren't comparing apples to apples; you have a "builder" Lennox or a SINGLE stage Lennox (I think the G51V is a good one--variable speed, 92.1% AFUE, etc.). The Frigidaire units are dual stage, which provides more comfort (low stage and high stage).
--------------------------------------------------------------------------------
RE: Frigidaire vs Lennox gas furnace clip this post email this post what is this?
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Posted by mikenew (My Page) on Sat, Mar 1, 08 at 8:30
The tech had to shut you down for liability reasons but your not going to endanger your family by turning your heat on it is physically impossible for combustion product to get in your airstream in that furnace as the indoor air passing through your heat exchanger is positive pressure the worry is your indoor air making it into the combustion chamber and causing the flame to rollout but there should be safeties in place to shut down if that happens
Manual 'J' and Foam Insulation clip this post email this post what is this?
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Posted by lsufan (My Page) on Fri, Feb 29, 08 at 21:46
New house under construction. Live in South Louisiana. Most windows on North side of home. Foam under the roof deck(5-6 inches) and in the walls(3-4 inches) of a two story 6000 sq. ft. home. Manual J performed by several HVAC contractors...all provide for 5 ac units (varying tonnage)for a total tonnage of 16-18 tons! Told that the Manual J program does not always take into account the significance of the foam insulation....told program makes no allowance for anything with R value greater than 19.
Told by foam contractor that 16-18 tons of ac way high...suggest we could get away with as little as 6-8 tons. BTW, going with American Standard 18 SEER units with variable speed handlers.
What gives? Would think that we could get away with much less tonnage and number of units.
--------------------------------------------------------------------------------
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RE: Manual 'J' and Foam Insulation clip this post email this post what is this?
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Posted by mikenew (My Page) on Sat, Mar 1, 08 at 8:15
Manual J only knows what it is told and they don't know what to tell there is an R value to your structure period and that is what you need to know the foam contractor needs to talk to your HVAC guys. Kinda discouraging that five companies can't figure that out, SCARY!
do you think it's possible to keep the same refriderant lines that run from the condensor and air handler? they run inside interior walls and there is no real access to the crawl space on second floor where the handler is from an exterior wall.
Thanks for your help.
Both in and out need to go. Best to let a pro do it but maybe he would let you help him! Maybe let you wire it?
__________________
IAQ/HVAC for the past 13 years and still learning
Replacing an old condensor
--------------------------------------------------------------------------------
Hello, I am curious...I have 2 trane condesors outside from 1988. One still works fine, however the other can't hold a refridgerant charge for more than a month. Was told that we probably had to replace the unit. Was wondering if that just meant just the unit outside or if the air handlers inside needed replacing as well. Also is that something I could do myself or would it be wise to have a professional do it? Thanks for any help, as it is very appreciated.
mike n
AC Repair AC Coil Leaking
--------------------------------------------------------------------------------
If you replace the condensor the evaporator definitely needs to go as this is probably leaking also and the efficiencies of the equipment will not match and there are warranty issues also. If the lineset is properly sized there is no reason you can't keep it but it is possible it's not the right size make sure you check it yourself
mike n
If the charge is leaking out in a month then the leak is freakin' huge and it should be pretty easy to find it. They said you would 'probably' have to replace it? Did they locate the leak?
Depending on where the leak is it could be repairable easily enough if it's on exposed copper. (big IF) The thing is it will still cost you an unpleasant ammount of cash to do it.
...so I'm going to agree with the guys below here...
If the thing is 20 years old consider this an early wake up call before summer hits and just try and figure out how your going to pay for a new unit. Replace the inside and outside unit. No point in having a system that old and you pay to have the condenser replaced only to find next year your going to have to have the air handler replaced when you could have saved a few bucks now on trip time and labor and had it all done at once.
The thing with fixing a leak on an old system is that it stands a good chance of happening again :/
Michael
see most clipped and recent clippings
Posted by nickt (My Page) on Fri, Feb 29, 08 at 15:02
We are being told that the smallest AC units available are 1.5 ton. But, we only have 450 sq ft to cool (bedroom, bathroom closet suite w/ 9 ft ceilings and an office with a 11 ft vaulted ceiling). Would a 1.5 unit (placed in the attic space) be grossly inefficient? Can you use strategic placement of the thermostat to try to get more dehumidification and prevent short cycling? Can you just blow the extra air out an attic vent or something?
We have looked into mini-splits and are concerned that a single unit would not be able to cool all four spaces effectively. Multiple units would just be overkill.
Any advice would be greatly appreciated.
--------------------------------------------------------------------------------
Follow-Up Postings:
RE: AC unit for 450 sqft clip this post email this post what is this?
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Posted by mikenew (My Page) on Sat, Mar 1, 08 at 8:19
It's hard for me to believe you can get all that in 450 sqft. there are multi zone mini splits that may help in this application, otherwise you can bring in some outside air and condition it to offset the oversizing
Frigidaire vs Lennox gas furnace clip this post email this post what is this?
see most clipped and recent clippings
Posted by lynnt (My Page) on Fri, Feb 29, 08 at 21:48
I live in the Washington DC area, in a 50-year-old 2300-sq-foot rambler. A service rep from my HVAC company shut down my 20-year-old Kenmore 80 1000-btu gas furnace this afternoon. He had run a camera on a cable up the burner flues into the heat exchanger, and showed me what he said were cracks: lighter lines among the black soot and more than a bit of rust. Although the monoxide alarms around the house and in the furnace room have not complained, he said the furnace was unsafe and must be replaced immediately.
OK, I can buy that the poor thing is at end of life. Question #1, do you agree that it had to be shut down immediately, or is this a pressure sales tactic? He didn't cut any wires, just turned off the breaker and the thermostat; is it safe for me to turn it back on?
Question #2, the sales rep is offering the following replacements, all 1000-btu Frigidaires (which I understand are made by Nordyne). What do you think of these furnaces, and does the price sound reasonable? They include running the required new exhaust PVC for the 93%er, plus all include $350 for running about 20 feet of flexible ducting to a badly-served dining-room addition.
80% 2-stage FG6TA096C12B $3500
80% 2-stage variable FG6RA096CVBA $4410
93% 2-stage FG6TC080CVBB $4550
The same company will replace my aged gas hot-water heater with a new 50-gal model for about $900, and add a system humidifier for about $650 if I do these at the same time as the furnace work. Comments?
Another company prefers Lennox furnaces; they say all I need is a 90K BTU furnace due to the increased efficiency these days -- though the old furnace was sized before the dining-room addition was built. They say the 80% Lennoxes are sturdy and far more reliable than the fancy Energy Star models. They are proposing:
80% G40 $2300
90% G51V $3400
and will do my hot-water heater for $625 along with the furnace replacement.
Is this apples and oranges? I really appreciate your input, and apologize for the long writeup. Both companies have good records in the area, and both have been around for more than a decade.
Lynn
--------------------------------------------------------------------------------
Follow-Up Postings:
RE: Frigidaire vs Lennox gas furnace clip this post email this post what is this?
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Posted by ryanhughes (My Page) on Fri, Feb 29, 08 at 22:56
The Lennox prices sound a bit low. Make sure you know what you're getting. Get all of it in writing: parts, materials, warranty, permit, etc. etc. Both brands are fine in my opinion. You really aren't comparing apples to apples; you have a "builder" Lennox or a SINGLE stage Lennox (I think the G51V is a good one--variable speed, 92.1% AFUE, etc.). The Frigidaire units are dual stage, which provides more comfort (low stage and high stage).
--------------------------------------------------------------------------------
RE: Frigidaire vs Lennox gas furnace clip this post email this post what is this?
see most clipped and recent clippings
Posted by mikenew (My Page) on Sat, Mar 1, 08 at 8:30
The tech had to shut you down for liability reasons but your not going to endanger your family by turning your heat on it is physically impossible for combustion product to get in your airstream in that furnace as the indoor air passing through your heat exchanger is positive pressure the worry is your indoor air making it into the combustion chamber and causing the flame to rollout but there should be safeties in place to shut down if that happens
Manual 'J' and Foam Insulation clip this post email this post what is this?
see most clipped and recent clippings
Posted by lsufan (My Page) on Fri, Feb 29, 08 at 21:46
New house under construction. Live in South Louisiana. Most windows on North side of home. Foam under the roof deck(5-6 inches) and in the walls(3-4 inches) of a two story 6000 sq. ft. home. Manual J performed by several HVAC contractors...all provide for 5 ac units (varying tonnage)for a total tonnage of 16-18 tons! Told that the Manual J program does not always take into account the significance of the foam insulation....told program makes no allowance for anything with R value greater than 19.
Told by foam contractor that 16-18 tons of ac way high...suggest we could get away with as little as 6-8 tons. BTW, going with American Standard 18 SEER units with variable speed handlers.
What gives? Would think that we could get away with much less tonnage and number of units.
--------------------------------------------------------------------------------
Follow-Up Postings:
RE: Manual 'J' and Foam Insulation clip this post email this post what is this?
see most clipped and recent clippings
Posted by mikenew (My Page) on Sat, Mar 1, 08 at 8:15
Manual J only knows what it is told and they don't know what to tell there is an R value to your structure period and that is what you need to know the foam contractor needs to talk to your HVAC guys. Kinda discouraging that five companies can't figure that out, SCARY!
do you think it's possible to keep the same refriderant lines that run from the condensor and air handler? they run inside interior walls and there is no real access to the crawl space on second floor where the handler is from an exterior wall.
Thanks for your help.
Both in and out need to go. Best to let a pro do it but maybe he would let you help him! Maybe let you wire it?
__________________
IAQ/HVAC for the past 13 years and still learning
Replacing an old condensor
--------------------------------------------------------------------------------
Hello, I am curious...I have 2 trane condesors outside from 1988. One still works fine, however the other can't hold a refridgerant charge for more than a month. Was told that we probably had to replace the unit. Was wondering if that just meant just the unit outside or if the air handlers inside needed replacing as well. Also is that something I could do myself or would it be wise to have a professional do it? Thanks for any help, as it is very appreciated.
mike n
AC Repair AC Coil Leaking
--------------------------------------------------------------------------------
If you replace the condensor the evaporator definitely needs to go as this is probably leaking also and the efficiencies of the equipment will not match and there are warranty issues also. If the lineset is properly sized there is no reason you can't keep it but it is possible it's not the right size make sure you check it yourself
mike n
If the charge is leaking out in a month then the leak is freakin' huge and it should be pretty easy to find it. They said you would 'probably' have to replace it? Did they locate the leak?
Depending on where the leak is it could be repairable easily enough if it's on exposed copper. (big IF) The thing is it will still cost you an unpleasant ammount of cash to do it.
...so I'm going to agree with the guys below here...
If the thing is 20 years old consider this an early wake up call before summer hits and just try and figure out how your going to pay for a new unit. Replace the inside and outside unit. No point in having a system that old and you pay to have the condenser replaced only to find next year your going to have to have the air handler replaced when you could have saved a few bucks now on trip time and labor and had it all done at once.
The thing with fixing a leak on an old system is that it stands a good chance of happening again :/
Michael
Friday, February 29, 2008
Clean air conditioner before spring
Clean air conditioner before spring
Cleaning your air conditioning unit is an easy task but one that many people overlook.
A clean air conditioner works more efficiently, costs less to operate and is less likely to require repair. Setting up a schedule for regular cleaning is a good maintenance practice, and one of the best times is now, before the season begins.
Tools, materials needed
1. Vacuum cleaner or shop vac
2. Garden hose
3. Screwdriver, pliers
4. HVAC cleaner (available in spray cans at hardware stores)
5. Shop cloth or soft bristle brush (such as an old toilet brush)
Instructions
Window air conditioner
1. Unplug the power cord from the outlet
2. Remove the filter cover on the inside of the house
3. Remove the filter and wash thoroughly with soap and water. Let it dry before putting it back in the unit.
4. Vacuum all of the dust and dirt from the unit that you can reach from the inside, and then go outside.
5. Spray the ventilation fins with the HVAC solvent and wipe or brush them clean. Straighten any bent fins with a pair of pliers.
6. Remove the outside cover, spraying the inside of the cover with HVAC solvent and rinsing it clean with water from the garden hose.
7. Vacuum the accumulated dirt and debris from the compressor coils. Look for evidence that the coils have been leaking or cracked. If you find damage to the coils, call an HVAC serviceman.
8. Spray the compressor unit with the HVAC solvent and let sit for a few minutes. Clean the coils with the cloth or brush. Vacuum once more to get any dust or dirt that was missed.
9. Replace the cover
Central air conditioner (outdoor compressor unit)
1. Turn off the power supply
2. With the screwdriver, remove the screws holding the fan assembly on top of the unit, and set it aside, using care not to cut or crimp the wires.
3. Remove all accumulated leaves, grass clippings and weeds that may have been pulled into the unit by the fan.
4. Spray the coils with HVAC solvent and let sit for a few minutes.
5. Spray the inside of the unit with the garden hose to clean thoroughly.
6. Clean the air ventilation fins on the outside of the unit with the solvent and the cloth or brush.
7. Straighten any bent fins with the pliers.
8. Replace the fan unit.
Cleaning your air conditioning unit is an easy task but one that many people overlook.
A clean air conditioner works more efficiently, costs less to operate and is less likely to require repair. Setting up a schedule for regular cleaning is a good maintenance practice, and one of the best times is now, before the season begins.
Tools, materials needed
1. Vacuum cleaner or shop vac
2. Garden hose
3. Screwdriver, pliers
4. HVAC cleaner (available in spray cans at hardware stores)
5. Shop cloth or soft bristle brush (such as an old toilet brush)
Instructions
Window air conditioner
1. Unplug the power cord from the outlet
2. Remove the filter cover on the inside of the house
3. Remove the filter and wash thoroughly with soap and water. Let it dry before putting it back in the unit.
4. Vacuum all of the dust and dirt from the unit that you can reach from the inside, and then go outside.
5. Spray the ventilation fins with the HVAC solvent and wipe or brush them clean. Straighten any bent fins with a pair of pliers.
6. Remove the outside cover, spraying the inside of the cover with HVAC solvent and rinsing it clean with water from the garden hose.
7. Vacuum the accumulated dirt and debris from the compressor coils. Look for evidence that the coils have been leaking or cracked. If you find damage to the coils, call an HVAC serviceman.
8. Spray the compressor unit with the HVAC solvent and let sit for a few minutes. Clean the coils with the cloth or brush. Vacuum once more to get any dust or dirt that was missed.
9. Replace the cover
Central air conditioner (outdoor compressor unit)
1. Turn off the power supply
2. With the screwdriver, remove the screws holding the fan assembly on top of the unit, and set it aside, using care not to cut or crimp the wires.
3. Remove all accumulated leaves, grass clippings and weeds that may have been pulled into the unit by the fan.
4. Spray the coils with HVAC solvent and let sit for a few minutes.
5. Spray the inside of the unit with the garden hose to clean thoroughly.
6. Clean the air ventilation fins on the outside of the unit with the solvent and the cloth or brush.
7. Straighten any bent fins with the pliers.
8. Replace the fan unit.
Wednesday, February 27, 2008
Getting ready for the Heat
Our friends in Texas are feeling it already don't let the summer find you unprepared download your free Homeowners Protection Guide today.
http://www.howtorepairairconditioners.com
Break in the heat a good time to get your A/C working
Don’t let today’s pleasant weather fool you — hot weather is on its way, and sooner than you think.
The Rio Grande Valley had a taste of summer weather Monday, as temperatures soared to the 90s.
In fact, McAllen set a new record high for that day when it reached 96 degrees at about 4 p.m.
The last record was 94 degrees, set in 1944, said Joseph Tomaselli, a meteorologist with the National Weather Service’s station in Brownsville. The Valley’s average temperatures for this time of year are in the mid- to high 70s, Tomaselli said.
Blame the heat on south and southwestern winds that preceded today’s cold front, said Greg Flatt, lead meteorologist for the National Weather Service. Temperatures are forecast to only reach the mid 70s today and Wednesday. Then they are expected to jump back to the 80s later this week.
More cool days are anticipated throughout the next month or so, but come late April the hot weather will be here to stay, Flatt said.
“Our summer gets here a little sooner,” he said.
So now would be a good time to make sure your air conditioning unit is properly working.
People should have their air conditioning units checked at least once a year and regularly replace filters to avoid any unexpected problems when they need cold air the most, according to local air conditioning repairmen.
Jose Avendano, owner of Cardenas Air and Heat in McAllen said people should keep up with their air conditioning unit maintenance like they keep up the maintenance of their cars.
“How often do you wash your car? Every time it’s dirty,” he said.
Homeowners should check the outdoor and indoor units to see how dirty the system is. If their unit needs cleaning, call a professional instead of trying it yourself so as to not risk getting hurt or damaging the unit, Avendano said. He also urged homeowners to check the batteries on their thermostats once a year to make sure it’s giving the right readings.
Another way to keep repair costs and temperatures low is to sign a maintenance agreement with a repair company you trust, said Ramon Gonzalez, owner of Azteca Electrical and Mechanical in McAllen.
Under the agreement, technicians check the air conditioning units at least once a year to make sure everything is smoothly running. Technicians can give the owners a heads-up to any potential problems and fix them before they become a larger and more expensive one, Gonzalez said. Contract prices vary by company.
Gonzalez also encouraged homeowners to clean out the coils because they’ve been known to collect ants, pet hair and other debris from outside.
Now, when the weather is still temperate, is the best time to check air conditioning units, because when summer comes it will be harder finding a technician who is readily available, he said.
http://www.howtorepairairconditioners.com
Break in the heat a good time to get your A/C working
Don’t let today’s pleasant weather fool you — hot weather is on its way, and sooner than you think.
The Rio Grande Valley had a taste of summer weather Monday, as temperatures soared to the 90s.
In fact, McAllen set a new record high for that day when it reached 96 degrees at about 4 p.m.
The last record was 94 degrees, set in 1944, said Joseph Tomaselli, a meteorologist with the National Weather Service’s station in Brownsville. The Valley’s average temperatures for this time of year are in the mid- to high 70s, Tomaselli said.
Blame the heat on south and southwestern winds that preceded today’s cold front, said Greg Flatt, lead meteorologist for the National Weather Service. Temperatures are forecast to only reach the mid 70s today and Wednesday. Then they are expected to jump back to the 80s later this week.
More cool days are anticipated throughout the next month or so, but come late April the hot weather will be here to stay, Flatt said.
“Our summer gets here a little sooner,” he said.
So now would be a good time to make sure your air conditioning unit is properly working.
People should have their air conditioning units checked at least once a year and regularly replace filters to avoid any unexpected problems when they need cold air the most, according to local air conditioning repairmen.
Jose Avendano, owner of Cardenas Air and Heat in McAllen said people should keep up with their air conditioning unit maintenance like they keep up the maintenance of their cars.
“How often do you wash your car? Every time it’s dirty,” he said.
Homeowners should check the outdoor and indoor units to see how dirty the system is. If their unit needs cleaning, call a professional instead of trying it yourself so as to not risk getting hurt or damaging the unit, Avendano said. He also urged homeowners to check the batteries on their thermostats once a year to make sure it’s giving the right readings.
Another way to keep repair costs and temperatures low is to sign a maintenance agreement with a repair company you trust, said Ramon Gonzalez, owner of Azteca Electrical and Mechanical in McAllen.
Under the agreement, technicians check the air conditioning units at least once a year to make sure everything is smoothly running. Technicians can give the owners a heads-up to any potential problems and fix them before they become a larger and more expensive one, Gonzalez said. Contract prices vary by company.
Gonzalez also encouraged homeowners to clean out the coils because they’ve been known to collect ants, pet hair and other debris from outside.
Now, when the weather is still temperate, is the best time to check air conditioning units, because when summer comes it will be harder finding a technician who is readily available, he said.
Monday, February 25, 2008
Troubleshooting traps and tricks
SOLUTION TO OUR LAST PROBLEM
To begin, here is the answer to our Dec. 3, 2007 issue troubleshooting problem, “An Electric Heating System That’s Not Heating Enough.”
In order to get this unit back on line, we need to replace two heating elements, HE1 and HE2. As sometimes happens in residential heating units, customers don’t realize that one element has gone out at some point in the past, and may not call for service until the heating capacity of the unit drops low enough for them to notice (with the failure of the second element). Both elements were proven to have failed since proper voltage was applied, but the measured current draw in their circuits was zero.
And, now on to this issue’s problem.
A GAS FURNACE FOLLOW-UP SERVICE CALL
Since we’re still in the “heating season mode” our troubleshooting problem this time around is focused on a customer who has called to say that “the room gets too warm before the furnace cycles off.” This is actually a follow-up situation, and here are some details:
• This is a new tenant in a residential rental, and after moving in and turning up the heat, they note that the burners turn on and the blower motor operates, but it seems to them that the house gets too warm before the unit cycles off.
• When you arrive, you note that this is a standard natural gas upflow furnace, with a standard electromechanical thermostat, which, according to the landlord (who took it upon himself to install), was installed last season when the furnace wasn’t operating at all.
• In your evaluation of the system’s performance, you choose a set point of 70°F and note that the room temperature does, in fact, go above that before the burners cycle off and the blower motor shuts down.
To begin your troubleshooting process, you disconnect the wiring from the thermostat sub-base and, using an analog ammeter and ten-wire wrap, you check the current draw of the control circuit. Figure 1 shows you the results of your test, and Figure 2 shows you the setting of the heat anticipator on the thermostat sub-base.
And your troubleshooting question is: What needs to be done in order to get this unit operating normally again?
If you have the answer to this question, Please respond to mike@howtorepairairconditioners.com otherwise wait for our follow up.
Author’s Side Note on Our Troubleshooting Problems
When you submit your diagnosis, feel free to include any additional thoughts and opinions about the scenario we present in addition to the answer to the problem. What do you think about the landlord in his do-it-yourself role? How about the choice of the replacement thermostat (about as inexpensive a model as possible) in a rental situation? How about using a digital meter rather than an analog meter to accomplish the test we illustrated? Any other thoughts on what you, as a service professional, should insist on doing to make sure you don’t find yourself in a problem situation after you leave this house? We will be publishing reader input along with the answer next time around.
To begin, here is the answer to our Dec. 3, 2007 issue troubleshooting problem, “An Electric Heating System That’s Not Heating Enough.”
In order to get this unit back on line, we need to replace two heating elements, HE1 and HE2. As sometimes happens in residential heating units, customers don’t realize that one element has gone out at some point in the past, and may not call for service until the heating capacity of the unit drops low enough for them to notice (with the failure of the second element). Both elements were proven to have failed since proper voltage was applied, but the measured current draw in their circuits was zero.
And, now on to this issue’s problem.
A GAS FURNACE FOLLOW-UP SERVICE CALL
Since we’re still in the “heating season mode” our troubleshooting problem this time around is focused on a customer who has called to say that “the room gets too warm before the furnace cycles off.” This is actually a follow-up situation, and here are some details:
• This is a new tenant in a residential rental, and after moving in and turning up the heat, they note that the burners turn on and the blower motor operates, but it seems to them that the house gets too warm before the unit cycles off.
• When you arrive, you note that this is a standard natural gas upflow furnace, with a standard electromechanical thermostat, which, according to the landlord (who took it upon himself to install), was installed last season when the furnace wasn’t operating at all.
• In your evaluation of the system’s performance, you choose a set point of 70°F and note that the room temperature does, in fact, go above that before the burners cycle off and the blower motor shuts down.
To begin your troubleshooting process, you disconnect the wiring from the thermostat sub-base and, using an analog ammeter and ten-wire wrap, you check the current draw of the control circuit. Figure 1 shows you the results of your test, and Figure 2 shows you the setting of the heat anticipator on the thermostat sub-base.
And your troubleshooting question is: What needs to be done in order to get this unit operating normally again?
If you have the answer to this question, Please respond to mike@howtorepairairconditioners.com otherwise wait for our follow up.
Author’s Side Note on Our Troubleshooting Problems
When you submit your diagnosis, feel free to include any additional thoughts and opinions about the scenario we present in addition to the answer to the problem. What do you think about the landlord in his do-it-yourself role? How about the choice of the replacement thermostat (about as inexpensive a model as possible) in a rental situation? How about using a digital meter rather than an analog meter to accomplish the test we illustrated? Any other thoughts on what you, as a service professional, should insist on doing to make sure you don’t find yourself in a problem situation after you leave this house? We will be publishing reader input along with the answer next time around.
Sunday, February 24, 2008
Help for someone with no Heat
Glad to help our Do It Youselfer Friends
oliverc
Advice on diagnosing Rheem furnace problem
--------------------------------------------------------------------------------
I have a Rheem Criterion model RGDG-05NAUER, and I need help diagnosing the problem, which started after the thing had been running almost continuously for a few cold days.
When the thermostat calls for heat, the induction draft blower starts up and does its 30 second prepurge. The igniter doesn't glow. The gas comes on for a few seconds, but, of course, it doesn't light. After that, it just waits for a while and goes through the same cycle over and over again.
According to the troubleshooting flow diagram, this could be caused by a defective "Air Proving Switch" (or pressure switch, I guess it's more often called), a blocked vent, a faulty igniter or a control-board/ wiring problem. I'm pretty sure the vent is OK. I just don't know how to check the pressure switch. How do I know if it's working or not? (According to the manual, it's supposed to be closed if it's working OK. I tried shorting it out, but then not even the draft blower would come on.)
If it is the pressure switch, where can I find a replacement? I've looked all over the web, and I can't find any replacement for this part, which is:
(The 6, 0 and 8 all look kind of the same, I can't be sure the number is right no matter how long I stare at the tiny printing!)
One last question, which probably isn't relevant to the problem but I'd like to know anyway: There's a limit switch on the hot side of the compartment. It's a small thing with a little red cylinder sticking up out of it. How do I know whether it's been triggered and needs to be reset? And how would I reset it if I had to? When I push down on it, there's no give -- it doesn't feel like it would go down no matter how hard I push.
I do have a multimeter, but it doesn't do continuity testing (yeah, I'm from the stone age).
Thanks for any help you can give me.
BTW, does anyone else find it really irritating that the manufacturer gives almost no help on this stuff? And that every service place in town (Los Angeles) refuses to sell parts? I mean, shouldn't a guy be allowed to try and fix his own furnace if he wants to?
oliverc
Furnace Repair
--------------------------------------------------------------------------------
It's not the switch or the gas valve wouldn't open you need to unplug the igniter and put two meter leads in the holes of the plug with the furnace off, set your meter to volts ac then turn the furnace on after purge you should get a voltage reading if you do the igniter is bad you should have a local rheem distributor but if you don't rheem or ruud either one can sell you the same part.
mike n
Thank you, thank you! It was just as you said: igniter was bust. You are smarter than the manual. Two hours of blood sweat and tears later, fiddling in the innards with a hex wrench, I have heat!
oliverc
Advice on diagnosing Rheem furnace problem
--------------------------------------------------------------------------------
I have a Rheem Criterion model RGDG-05NAUER, and I need help diagnosing the problem, which started after the thing had been running almost continuously for a few cold days.
When the thermostat calls for heat, the induction draft blower starts up and does its 30 second prepurge. The igniter doesn't glow. The gas comes on for a few seconds, but, of course, it doesn't light. After that, it just waits for a while and goes through the same cycle over and over again.
According to the troubleshooting flow diagram, this could be caused by a defective "Air Proving Switch" (or pressure switch, I guess it's more often called), a blocked vent, a faulty igniter or a control-board/ wiring problem. I'm pretty sure the vent is OK. I just don't know how to check the pressure switch. How do I know if it's working or not? (According to the manual, it's supposed to be closed if it's working OK. I tried shorting it out, but then not even the draft blower would come on.)
If it is the pressure switch, where can I find a replacement? I've looked all over the web, and I can't find any replacement for this part, which is:
(The 6, 0 and 8 all look kind of the same, I can't be sure the number is right no matter how long I stare at the tiny printing!)
One last question, which probably isn't relevant to the problem but I'd like to know anyway: There's a limit switch on the hot side of the compartment. It's a small thing with a little red cylinder sticking up out of it. How do I know whether it's been triggered and needs to be reset? And how would I reset it if I had to? When I push down on it, there's no give -- it doesn't feel like it would go down no matter how hard I push.
I do have a multimeter, but it doesn't do continuity testing (yeah, I'm from the stone age).
Thanks for any help you can give me.
BTW, does anyone else find it really irritating that the manufacturer gives almost no help on this stuff? And that every service place in town (Los Angeles) refuses to sell parts? I mean, shouldn't a guy be allowed to try and fix his own furnace if he wants to?
oliverc
Furnace Repair
--------------------------------------------------------------------------------
It's not the switch or the gas valve wouldn't open you need to unplug the igniter and put two meter leads in the holes of the plug with the furnace off, set your meter to volts ac then turn the furnace on after purge you should get a voltage reading if you do the igniter is bad you should have a local rheem distributor but if you don't rheem or ruud either one can sell you the same part.
mike n
Thank you, thank you! It was just as you said: igniter was bust. You are smarter than the manual. Two hours of blood sweat and tears later, fiddling in the innards with a hex wrench, I have heat!
AC in the Attic Frustration
Here are some installation opinions from the northeast.
While attic installation of an air handler does present a few problems if installation is done properly and ductwork is sealed there is no reason that an attic installation cannot be a good fit especially if you don't like sweating to death upstairs in the summer, but you let me know what you think.
An attic is no place for a heating unit
Q.I have a gas furnace in my attic, where it was installed some time ago in the house that was built in 1937, with 3,000 square feet of living space. It is not heating very well, and two dealers offered ideas: One suggested installing a new hot-air unit fired by gas. Another suggested hydro air, a boiler in the attic that heats hot air that is blown into the second-floor living area. What should I do?
LAURIE, from Newton
A.Here we go again, when designers and contractors are putting air-conditioning units (not compressors, thank goodness) and heating units into attics. Generally, the idea is to share the space in large houses, with one unit in the basement to serve the first floor, another in the attic to serve the second and higher floors. In the Handyman's opinion, it is not a good idea, and in both cases these units should be removed from the attic.
In Michael Keegan's house, the air-conditioning unit (not a compressor, which should remain outdoors) is a distributor, with air flowing over cold coils and cooled as it is distributed to the house, or at least to the second floor. The problem is the unit is releasing a lot of water vapor into the attic, where it condenses on the cool ceiling and allows mold to grow. These units are usually airtight, but a leak may have occurred to allow that water vapor to escape. That can be fixed, and I suggest Mr. Keegan contact the dealer to get it fixed.
It would be better to relocate the unit to a proper room on the second floor, where excess water vapor could be exausted. Some engineers feel there is enough ventilation in an attic to handle the heat or water vapor, but the Handyman is not convinced this is so.
Ms. Laurie's problem is similar, but with a furnace that is not working very well. A good dealer might be able to fix that, but better would be to relocate that furnace, even if it has a power vent through an attic wall or through the roof. You can insulate the furnace, but you cannot insulate an open gas flame. Therefore, sooner or later, the unit will pump out a lot of water vapor and possibly heat, causing possible growth of mold, and possibly ice dams.
gas furnace with a power vent could be located on the second floor. If the house is big enough, this should not be a problem.
more stories like this Finally, most houses are not so big that they need two heating or two air-conditioning units. A lot of big houses are heated and cooled by one unit. That may sound old-fashioned, but it works better than some of the new-fangled ideas that are floating round these days.
While attic installation of an air handler does present a few problems if installation is done properly and ductwork is sealed there is no reason that an attic installation cannot be a good fit especially if you don't like sweating to death upstairs in the summer, but you let me know what you think.
An attic is no place for a heating unit
Q.I have a gas furnace in my attic, where it was installed some time ago in the house that was built in 1937, with 3,000 square feet of living space. It is not heating very well, and two dealers offered ideas: One suggested installing a new hot-air unit fired by gas. Another suggested hydro air, a boiler in the attic that heats hot air that is blown into the second-floor living area. What should I do?
LAURIE, from Newton
A.Here we go again, when designers and contractors are putting air-conditioning units (not compressors, thank goodness) and heating units into attics. Generally, the idea is to share the space in large houses, with one unit in the basement to serve the first floor, another in the attic to serve the second and higher floors. In the Handyman's opinion, it is not a good idea, and in both cases these units should be removed from the attic.
In Michael Keegan's house, the air-conditioning unit (not a compressor, which should remain outdoors) is a distributor, with air flowing over cold coils and cooled as it is distributed to the house, or at least to the second floor. The problem is the unit is releasing a lot of water vapor into the attic, where it condenses on the cool ceiling and allows mold to grow. These units are usually airtight, but a leak may have occurred to allow that water vapor to escape. That can be fixed, and I suggest Mr. Keegan contact the dealer to get it fixed.
It would be better to relocate the unit to a proper room on the second floor, where excess water vapor could be exausted. Some engineers feel there is enough ventilation in an attic to handle the heat or water vapor, but the Handyman is not convinced this is so.
Ms. Laurie's problem is similar, but with a furnace that is not working very well. A good dealer might be able to fix that, but better would be to relocate that furnace, even if it has a power vent through an attic wall or through the roof. You can insulate the furnace, but you cannot insulate an open gas flame. Therefore, sooner or later, the unit will pump out a lot of water vapor and possibly heat, causing possible growth of mold, and possibly ice dams.
gas furnace with a power vent could be located on the second floor. If the house is big enough, this should not be a problem.
more stories like this Finally, most houses are not so big that they need two heating or two air-conditioning units. A lot of big houses are heated and cooled by one unit. That may sound old-fashioned, but it works better than some of the new-fangled ideas that are floating round these days.
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