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#1
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heat pump problem
I have a Trane heatpump that is about 12 years old. In the summer it cools fine. Last winter the house was about 2 deg cooler than the thermostat was set for. Noticed the inside air handler was running,but the outside unit was not. Checked and had power. The relay that puts power to the compressor and fan was not pulled in. The coil did not have any voltage on it. The circuit board has a led that blinks once per second like the paper in the pump says it should if everything is ok. I cut it off by the thermostat and then 5 minuits later turned it on. Everything is working fine now. The heatpump did that to be about 3 or 4 times last year. I don't recall the temperature then,but today it was about 40 deg F outside. It was 66 inside instead of 68 like it was set for. I don't mind calling a man for service, but there would not be anything I know of for him to find. Any ideas on why the outside unit will not cycle off and on like it should ? Maybe it goes into the defrost mode and gets hung up ? |
#2
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heat pump problem
On Thursday, November 28, 2019 at 12:28:16 PM UTC-5, Ralph Mowery wrote:
I have a Trane heatpump that is about 12 years old. In the summer it cools fine. Last winter the house was about 2 deg cooler than the thermostat was set for. Noticed the inside air handler was running,but the outside unit was not. Checked and had power. The relay that puts power to the compressor and fan was not pulled in. The coil did not have any voltage on it. The circuit board has a led that blinks once per second like the paper in the pump says it should if everything is ok. I cut it off by the thermostat and then 5 minuits later turned it on. Everything is working fine now. The heatpump did that to be about 3 or 4 times last year. I don't recall the temperature then,but today it was about 40 deg F outside. It was 66 inside instead of 68 like it was set for. I don't mind calling a man for service, but there would not be anything I know of for him to find. Any ideas on why the outside unit will not cycle off and on like it should ? Maybe it goes into the defrost mode and gets hung up ? IDK how heat pump systems call for heat. Is there one wire that says make heat, another one that turns the blower on? Or does one wire say make heat and the system turns the blower on? If it's the latter, then since the blower is running you can rule out the thermostat. If it's two wires, then it's possible it's a thermostat problem. I agree that calling for service on something like this is really bad. They won't see it happening and even if they do, probably won't have any more idea what to do that you do. |
#3
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heat pump problem
On Thursday, November 28, 2019 at 8:11:12 PM UTC-5, trader_4 wrote:
On Thursday, November 28, 2019 at 12:28:16 PM UTC-5, Ralph Mowery wrote: I have a Trane heatpump that is about 12 years old. In the summer it cools fine. Last winter the house was about 2 deg cooler than the thermostat was set for. Noticed the inside air handler was running,but the outside unit was not. Checked and had power. The relay that puts power to the compressor and fan was not pulled in. The coil did not have any voltage on it. The circuit board has a led that blinks once per second like the paper in the pump says it should if everything is ok. I cut it off by the thermostat and then 5 minuits later turned it on. Everything is working fine now. The heatpump did that to be about 3 or 4 times last year. I don't recall the temperature then,but today it was about 40 deg F outside. It was 66 inside instead of 68 like it was set for. I don't mind calling a man for service, but there would not be anything I know of for him to find. Any ideas on why the outside unit will not cycle off and on like it should ? Maybe it goes into the defrost mode and gets hung up ? IDK how heat pump systems call for heat. Is there one wire that says make heat, another one that turns the blower on? Or does one wire say make heat and the system turns the blower on? If it's the latter, then since the blower is running you can rule out the thermostat. If it's two wires, then it's possible it's a thermostat problem. I agree that calling for service on something like this is really bad. They won't see it happening and even if they do, probably won't have any more idea what to do that you do. Another question, what does it do when it's 66/68 and you just leave it? Does it eventually come on? Does it go back on when it drops to 65?, etc. Or does the compressor just stay off indefinitely? What was it doing just before, was it maintaining 68? If so, then you'd think it must stay off a long time when it's 40 outside for inside to drop two degrees. |
#4
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heat pump problem
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#5
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heat pump problem
On Thu, 28 Nov 2019 17:11:06 -0800 (PST), trader_4
wrote: On Thursday, November 28, 2019 at 12:28:16 PM UTC-5, Ralph Mowery wrote: I have a Trane heatpump that is about 12 years old. In the summer it cools fine. Last winter the house was about 2 deg cooler than the thermostat was set for. Noticed the inside air handler was running,but the outside unit was not. Checked and had power. The relay that puts power to the compressor and fan was not pulled in. The coil did not have any voltage on it. The circuit board has a led that blinks once per second like the paper in the pump says it should if everything is ok. I cut it off by the thermostat and then 5 minuits later turned it on. Everything is working fine now. The heatpump did that to be about 3 or 4 times last year. I don't recall the temperature then,but today it was about 40 deg F outside. It was 66 inside instead of 68 like it was set for. I don't mind calling a man for service, but there would not be anything I know of for him to find. Any ideas on why the outside unit will not cycle off and on like it should ? Maybe it goes into the defrost mode and gets hung up ? IDK how heat pump systems call for heat. Is there one wire that says make heat, another one that turns the blower on? Or does one wire say make heat and the system turns the blower on? If it's the latter, then since the blower is running you can rule out the thermostat. If it's two wires, then it's possible it's a thermostat problem. I agree that calling for service on something like this is really bad. They won't see it happening and even if they do, probably won't have any more idea what to do that you do. in the thermostat cable The white wire calls for heat (W2 calls the toaster wire) The green wire turns on the fan. Yellow is AC Going out to the condenser it is either an orange or blue wire that turns on the reversing valve (manufacturer dependent) |
#6
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heat pump problem
On Thursday, November 28, 2019 at 9:41:03 PM UTC-5, wrote:
On Thu, 28 Nov 2019 17:11:06 -0800 (PST), trader_4 wrote: On Thursday, November 28, 2019 at 12:28:16 PM UTC-5, Ralph Mowery wrote: I have a Trane heatpump that is about 12 years old. In the summer it cools fine. Last winter the house was about 2 deg cooler than the thermostat was set for. Noticed the inside air handler was running,but the outside unit was not. Checked and had power. The relay that puts power to the compressor and fan was not pulled in. The coil did not have any voltage on it. The circuit board has a led that blinks once per second like the paper in the pump says it should if everything is ok. I cut it off by the thermostat and then 5 minuits later turned it on. Everything is working fine now. The heatpump did that to be about 3 or 4 times last year. I don't recall the temperature then,but today it was about 40 deg F outside. It was 66 inside instead of 68 like it was set for. I don't mind calling a man for service, but there would not be anything I know of for him to find. Any ideas on why the outside unit will not cycle off and on like it should ? Maybe it goes into the defrost mode and gets hung up ? IDK how heat pump systems call for heat. Is there one wire that says make heat, another one that turns the blower on? Or does one wire say make heat and the system turns the blower on? If it's the latter, then since the blower is running you can rule out the thermostat. If it's two wires, then it's possible it's a thermostat problem. I agree that calling for service on something like this is really bad. They won't see it happening and even if they do, probably won't have any more idea what to do that you do. in the thermostat cable The white wire calls for heat (W2 calls the toaster wire) The green wire turns on the fan. Yellow is AC Going out to the condenser it is either an orange or blue wire that turns on the reversing valve (manufacturer dependent) But when it calls for heat does the thermostat activate the W wire and the G fan wire? Or just the W wire? With furnaces, it only activates the W wire, the furnace then turns on the blower. The G wire in the furnace application is if you want to manually put the blower on, without heat. That matters with Ralph's problem. If it takes two wires to work it, then it's possibly a thermostat problem or issue with the W wire. If it just takes activating the W wire, then the thermostat and wiring aren't the problem, because his blower is running. I guess regardless I would get it set up so that I could measure the voltage at the W and G terminals at the air handler control board when it's having the problem. That might require taping over a cut off switch on a panel. I'd also inspect the relay on the control board that drives the compressor unit, if possible. Maybe the relay is sticking/failing and sometimes it will not close to activate. He should also measure the voltage at the control board that goes to the compressor when it's having the problem, see if it has voltage or not. That would help determine if it's before that point or an intermittent wiring problem going to the compressor unit. But it doesn't seem like a wiring thing, since recycling the power restores normal operation. So far, it sounds most likely a control board problem. If it looks like that's it, he could buy a new one. If it turns out that it's not that, very good chance he can sell it on Ebay and get most of his money back. Very cheap compared to what it would cost to call out an HVAC guy. the compressor. |
#7
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heat pump problem
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#9
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heat pump problem
On Fri, 29 Nov 2019 11:02:59 -0500, Ralph Mowery
wrote: In article , says... I'd also inspect the relay on the control board that drives the compressor unit, if possible. Maybe the relay is sticking/failing and sometimes it will not close to activate. He should also measure the voltage at the control board that goes to the compressor when it's having the problem, see if it has voltage or not. That would help determine if it's before that point or an intermittent wiring problem going to the compressor unit. But it doesn't seem like a wiring thing, since recycling the power restores normal operation. So far, it sounds most likely a control board problem. If it looks like that's it, he could buy a new one. If it turns out that it's not that, very good chance he can sell it on Ebay and get most of his money back. Very cheap compared to what it would cost to call out an HVAC guy. the compressor. I worked for years as an electrician and instrument person at a large plant, so doing the actual work and measurment ( I have all kinds of test instruments at home) is no problem. I dealt with computer controled equipment and some 480 volt 3 phase heaters that pulled about 300 amps. Just knowing what to look for on this simple controller is my problem. That thing just will not stay screwed up long enough to find the problem. It only does it a few times in the winter. Just started a year or two ago. I did check the relay that powers the compressor and fan. It did not have any power going to them. Pushing it in by hand (screwdriver) starts them. I may buy a control board off ebay. Seems that I looked into it last year but did not follow up when I bought a spare capacitor and relay just so I would have them at hand. The board would be cheap compaired to calling the man. I learned my lesson on that a few years back when I was charged about $ 350 just to have the capacitor replaced. Since you do seem to have skills, it might be worth making up a test light with an LED and a 2k or so resistor and hanging it on the white wire and maybe another one on the green.. Then if that is OK start moving it closer to the relay that is not getting the pick shot. You can leave it connected and look at it when it is working, again when it is failing. In a few failures, you should be able to find the bad part. |
#10
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heat pump problem
On Fri, 29 Nov 2019 11:02:59 -0500, Ralph Mowery
wrote: In article , says... I'd also inspect the relay on the control board that drives the compressor unit, if possible. Maybe the relay is sticking/failing and sometimes it will not close to activate. He should also measure the voltage at the control board that goes to the compressor when it's having the problem, see if it has voltage or not. That would help determine if it's before that point or an intermittent wiring problem going to the compressor unit. But it doesn't seem like a wiring thing, since recycling the power restores normal operation. So far, it sounds most likely a control board problem. If it looks like that's it, he could buy a new one. If it turns out that it's not that, very good chance he can sell it on Ebay and get most of his money back. Very cheap compared to what it would cost to call out an HVAC guy. the compressor. I worked for years as an electrician and instrument person at a large plant, so doing the actual work and measurment ( I have all kinds of test instruments at home) is no problem. I dealt with computer controled equipment and some 480 volt 3 phase heaters that pulled about 300 amps. Just knowing what to look for on this simple controller is my problem. That thing just will not stay screwed up long enough to find the problem. It only does it a few times in the winter. Just started a year or two ago. I did check the relay that powers the compressor and fan. It did not have any power going to them. Pushing it in by hand (screwdriver) starts them. I may buy a control board off ebay. Seems that I looked into it last year but did not follow up when I bought a spare capacitor and relay just so I would have them at hand. The board would be cheap compaired to calling the man. I learned my lesson on that a few years back when I was charged about $ 350 just to have the capacitor replaced. Personally "I" would start by checking ALL connections in the low voltage control circuit. clean all contacts to "bright" and reinstall with de-oxit or similar connection "dope". Any place with push or slide connections, buff the contacts with a hard pink eraser. Also trty wiggling any solid core wires to check for cracks, and check for ANY evidence of moisture, corrosion, or buf nests. |
#11
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heat pump problem
On Fri, 29 Nov 2019 07:01:57 -0800 (PST), trader_4
wrote: On Thursday, November 28, 2019 at 9:41:03 PM UTC-5, wrote: On Thu, 28 Nov 2019 17:11:06 -0800 (PST), trader_4 wrote: On Thursday, November 28, 2019 at 12:28:16 PM UTC-5, Ralph Mowery wrote: I have a Trane heatpump that is about 12 years old. In the summer it cools fine. Last winter the house was about 2 deg cooler than the thermostat was set for. Noticed the inside air handler was running,but the outside unit was not. Checked and had power. The relay that puts power to the compressor and fan was not pulled in. The coil did not have any voltage on it. The circuit board has a led that blinks once per second like the paper in the pump says it should if everything is ok. I cut it off by the thermostat and then 5 minuits later turned it on. Everything is working fine now. The heatpump did that to be about 3 or 4 times last year. I don't recall the temperature then,but today it was about 40 deg F outside. It was 66 inside instead of 68 like it was set for. I don't mind calling a man for service, but there would not be anything I know of for him to find. Any ideas on why the outside unit will not cycle off and on like it should ? Maybe it goes into the defrost mode and gets hung up ? IDK how heat pump systems call for heat. Is there one wire that says make heat, another one that turns the blower on? Or does one wire say make heat and the system turns the blower on? If it's the latter, then since the blower is running you can rule out the thermostat. If it's two wires, then it's possible it's a thermostat problem. I agree that calling for service on something like this is really bad. They won't see it happening and even if they do, probably won't have any more idea what to do that you do. in the thermostat cable The white wire calls for heat (W2 calls the toaster wire) The green wire turns on the fan. Yellow is AC Going out to the condenser it is either an orange or blue wire that turns on the reversing valve (manufacturer dependent) But when it calls for heat does the thermostat activate the W wire and the G fan wire? Or just the W wire? With furnaces, it only activates the W wire, the furnace then turns on the blower. The G wire in the furnace application is if you want to manually put the blower on, without heat. That matters with Ralph's problem. If it takes two wires to work it, then it's possibly a thermostat problem or issue with the W wire. If it just takes activating the W wire, then the thermostat and wiring aren't the problem, because his blower is running. I guess regardless I would get it set up so that I could measure the voltage at the W and G terminals at the air handler control board when it's having the problem. That might require taping over a cut off switch on a panel. I'd also inspect the relay on the control board that drives the compressor unit, if possible. Maybe the relay is sticking/failing and sometimes it will not close to activate. He should also measure the voltage at the control board that goes to the compressor when it's having the problem, see if it has voltage or not. That would help determine if it's before that point or an intermittent wiring problem going to the compressor unit. But it doesn't seem like a wiring thing, since recycling the power restores normal operation. So far, it sounds most likely a control board problem. If it looks like that's it, he could buy a new one. If it turns out that it's not that, very good chance he can sell it on Ebay and get most of his money back. Very cheap compared to what it would cost to call out an HVAC guy. the compressor. The heat will not run unless the fan is on and depending on the thermostat base, you might have to turn the fan switch on to get heat. I am not sure about furnaces, I haven't seen one in 35 years but that is how air handlers work. I do know you can run most heat only furnaces on a 2 wire thermostat (just reading the instructions for thermostats). He is definitely in the situation where poking around with a meter (even a 24v test light) and looking at the wiring diagram is in order. Just throwing parts at it and trying to get lucky is silly. |
#12
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heat pump problem
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#13
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heat pump problem
On Friday, November 29, 2019 at 11:27:29 AM UTC-5, wrote:
On Fri, 29 Nov 2019 07:01:57 -0800 (PST), trader_4 wrote: On Thursday, November 28, 2019 at 9:41:03 PM UTC-5, wrote: On Thu, 28 Nov 2019 17:11:06 -0800 (PST), trader_4 wrote: On Thursday, November 28, 2019 at 12:28:16 PM UTC-5, Ralph Mowery wrote: I have a Trane heatpump that is about 12 years old. In the summer it cools fine. Last winter the house was about 2 deg cooler than the thermostat was set for. Noticed the inside air handler was running,but the outside unit was not. Checked and had power. The relay that puts power to the compressor and fan was not pulled in. The coil did not have any voltage on it. The circuit board has a led that blinks once per second like the paper in the pump says it should if everything is ok. I cut it off by the thermostat and then 5 minuits later turned it on. Everything is working fine now. The heatpump did that to be about 3 or 4 times last year. I don't recall the temperature then,but today it was about 40 deg F outside. It was 66 inside instead of 68 like it was set for. I don't mind calling a man for service, but there would not be anything I know of for him to find. Any ideas on why the outside unit will not cycle off and on like it should ? Maybe it goes into the defrost mode and gets hung up ? IDK how heat pump systems call for heat. Is there one wire that says make heat, another one that turns the blower on? Or does one wire say make heat and the system turns the blower on? If it's the latter, then since the blower is running you can rule out the thermostat. If it's two wires, then it's possible it's a thermostat problem. I agree that calling for service on something like this is really bad. They won't see it happening and even if they do, probably won't have any more idea what to do that you do. in the thermostat cable The white wire calls for heat (W2 calls the toaster wire) The green wire turns on the fan. Yellow is AC Going out to the condenser it is either an orange or blue wire that turns on the reversing valve (manufacturer dependent) But when it calls for heat does the thermostat activate the W wire and the G fan wire? Or just the W wire? With furnaces, it only activates the W wire, the furnace then turns on the blower. The G wire in the furnace application is if you want to manually put the blower on, without heat. That matters with Ralph's problem. If it takes two wires to work it, then it's possibly a thermostat problem or issue with the W wire. If it just takes activating the W wire, then the thermostat and wiring aren't the problem, because his blower is running. I guess regardless I would get it set up so that I could measure the voltage at the W and G terminals at the air handler control board when it's having the problem. That might require taping over a cut off switch on a panel. I'd also inspect the relay on the control board that drives the compressor unit, if possible. Maybe the relay is sticking/failing and sometimes it will not close to activate. He should also measure the voltage at the control board that goes to the compressor when it's having the problem, see if it has voltage or not. That would help determine if it's before that point or an intermittent wiring problem going to the compressor unit. But it doesn't seem like a wiring thing, since recycling the power restores normal operation. So far, it sounds most likely a control board problem. If it looks like that's it, he could buy a new one. If it turns out that it's not that, very good chance he can sell it on Ebay and get most of his money back. Very cheap compared to what it would cost to call out an HVAC guy. the compressor. The heat will not run unless the fan is on and depending on the thermostat base, you might have to turn the fan switch on to get heat. I am not sure about furnaces, I haven't seen one in 35 years but that is how air handlers work. Furnace is as I described. The thermostat just calls for heat on the W wire (or wires if it's two stage), the furnace does the rest, ie turns the blower on after the furnace has fired for a minute or so. Old furnaces used to use a temp switch in the plenum to activate the blower. New ones just use a time delay on the controller board. An interesting side note with two stage furnaces. They can generally be set up two ways. One is really the right and best way, which is to use two heat call wires, one for each stage. The other way is to just use one wire and set it up so the control board makes the call based on how long the furnace runs. So, it starts at low stage, then if it's still running after ~ 8 mins or so, it goes to high. Obviously that's far from ideal. If you need a bigger increase in temp, you have to wait 8 mins for it to kick up. And it also might kick up and then shut off in a just another short period, if the temp was almost where it needed to be. The thermostat knows what the req increase is and can invoke high stage at the beginning. But it takes an extra wire, that many installs probably don't have. It also takes a two stage thermostat. I'd also bet that a lot of furnaces are installed using the inferior method anyway, because the installers are half-assed, don't want to change to a two stage thermostat, etc. I do know you can run most heat only furnaces on a 2 wire thermostat (just reading the instructions for thermostats). Bingo. He is definitely in the situation where poking around with a meter (even a 24v test light) and looking at the wiring diagram is in order. Just throwing parts at it and trying to get lucky is silly. I agree, I'd do more investigating, starting with what the voltages are at the inputs to the unit and at the activation terminal going to the heat pump. |
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