I have worked in the HVAC field for 25 years but have had very little exposure to Heat Pumps. I installed an American Standard HP in July, it worked fine for cooling. As we went into heating season, we switched over to heat, and it worked fine, cycling as it should. Since the Temperature has dropped below 35 degrees, the unit runs continously, it is not having a problem heating the house. It is about to run my wife out of here. Even with the T-stat turned to the off position the unit continues to run, the only way to stop it is to turn the voltage off at the furnace. I tried checking the connecting terminals for voltage but none is present at the white wires or the yellow connections, the T-stat is in the off position, it seems to be back feeding from the outside unit. I was wondering if there is some type of outdoor t-stat in the unit? This unit is R-22 and may be about 6 years old. I feel kinda dumb, but this wiring is about to drive me crazy. If the Temp. goes up the unit runs fine. The furnace is oil fired and does not fire even when I turn the T-stat to emergency heat, it may be the t-stat (White Rogers, two stage heat, 1 stage cool, 1F58-72) but I think I got the wiring messed up somehow.
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Heat pump runs continously below 35 degrees
- Thread starter TomBabik
- Start date
I don't know nuthin bout nuthin in terms of hvac, but both of my American standard heritage 14 heat pumps have outdoor thermostats installed so I can burn fossil fuel when the temp gets below my threshold (33F)
I wish I could help you?
I wish I could help you?
snorky18
Well-known member
I'm not good at reading long stretches with no paragraph breaks, but any chances you have a relay for the blower stuck on?
.....I've had both air source and ground source heat pumps over the years ....sounds like you have an air source with backup oil furnace. What I can tell you operationally - perhaps it will help you to regain your sanity a bit:
- the switch over to oil should be automatic and not until a much lower temp is reached (this is "20-year" memory talking but it seems to be the temp was around 5-10F when the oil furnace kicked in)
- you should be able to override (at the thermostat) the automatic switch over and force the oil furnace to come on (at any temperature)
- perhaps I am stating the obvious but the unit should not run continuously
- we did not have an outdoor thermostat on ours.
Is it possible that you simply have a faulty thermostat....( get one at Home depot .... if not the problem just return it. ) ?
- the switch over to oil should be automatic and not until a much lower temp is reached (this is "20-year" memory talking but it seems to be the temp was around 5-10F when the oil furnace kicked in)
- you should be able to override (at the thermostat) the automatic switch over and force the oil furnace to come on (at any temperature)
- perhaps I am stating the obvious but the unit should not run continuously
- we did not have an outdoor thermostat on ours.
Is it possible that you simply have a faulty thermostat....( get one at Home depot .... if not the problem just return it. ) ?
If you are in the business, then your best bet is to stop at the AM Std distributor in your area and discuss it with their tech rep. In my experience the AS dist typically have excellent support and are the best source of parts. What is the second stage heat on your heat pump?
I'm no pro, but I had one in AL. When the temp got cold it started running continuously (and using the electric secondary) our electric bills went through the roof. Turns out there was a bad solder joint somewhere outside and in the cold wether the coolant/freon/whatever... leaked out. It almost cost us a compressor. The installer fixed it for nothing, but we still had to pay the electric bills! (should have never happened)
danski0224
Well-known member
I have worked in the HVAC field for 25 years but have had very little exposure to Heat Pumps. I installed an American Standard HP in July, it worked fine for cooling. As we went into heating season, we switched over to heat, and it worked fine, cycling as it should. Since the Temperature has dropped below 35 degrees, the unit runs continously, it is not having a problem heating the house.
Something isn't wired properly, or you have the wrong thermostat.
I'd download the wiring instructions for the thermostat and double check it.
You are trying to do a dual fuel setup, and one of the best controllers is the Vision Pro IAQ with an outdoor temperature sensor.
As the temperature drops, the heat pump WILL run all the time. I don't think that thermostat has the capability to switch heating sources at a balance point, so the emergency heat will not kick on until the space starts cooling down, kicking in the second stage.
Hopefully, you did a load calc and know what your thermal and economic balance points are.
I have a 2 stage heat pump and 2 stage furnace controlled by the Vision Pro IAQ.
SteelHorseHD
Well-known member
How long have you waited after turning the T-stat off before you cut the juice to the unit? If I turn the T-stat off on mine the unit will continue to run for a short time afterwards (maybe 5 minutes tops)
My setup doesn't switch heat sources automatically but I have a switch on the side of my furnace that will shut the heat pump off and start the furnace.
My setup doesn't switch heat sources automatically but I have a switch on the side of my furnace that will shut the heat pump off and start the furnace.
Milton Shaw
Well-known member
- Joined
- Feb 11, 2011
- Messages
- 4,868
With all the electronics on units now, you probably need to get a repairman for that brand out there to check sensors/wiring to see if something is hooked up wrong. A neighbor has one of the high end 22 seer units and has had problems from boards, leaks and company that installed it is out of business now less than year old unit. Most HP's run based on indoor thermostat settings, depending on the sizing of the unit they may have to run continously at 35 to keep up with heat load in house vs. heat pump output. HP's are normally rated at 50 outside for say 36,000 BTU but that drops to 12,000 at 35 outside or less until it is using more electricity than its producing in HP mode then it cuts off and switches to aux heat. But from your message the unit is overheating the house and not cutting off at all. That sounds like wiring problem with thermostat or on unit at the relay board.
brihvac
Well-known member
A few things. I know with the Honeywell Vision Pro stats you have to set them up for your "specific" application. There are certain codes you have to put in to set it up for AC heatpump with fossil fuel back up. If you suspect a bad thermostat...take it off the wall and pull the red "R" wire. It should shut down. If it does than you know there is a stat issue. If it does not than you know the stat is ok. Is the contactor stuck on the outdoor unit? Pull the coil wire on the contactor and see if it shuts down? They are really not that hard, you just need to take your time so you dont get overwhelmed.