First post here and looking for some assistance with troubleshooting my heat pump. I have been living in my house for 2 years, I believe the system is original to the house and was installed in 1998. When I first moved into the house the heat pump worked fine, the system would heat and cool fine. In heat mode, if the temp dropped too much the aux heat would kick in. The system is a carrier weathermaker 8000TS heat pump system with a natural gas aux/emergency heat backup, the outdoor unit is a comfortmaker. The air conditioner works fine, no problems except with it freezing up twice this summer because 1) the indoor blower motor died and 2) after i replaced motor I had too many vents blocked off preventing sufficient airflow over the coil to prevent freezing. To elaborate on the previous cooling problem, I replaced the inside blower motor and capacitor as well as the outside compressor/fan capacitor. No more freeze ups once i corrected the mechanical failure and dumb move of blocking vents to boost airflow to upper floors. Lesson learned.
The AC part of the system works fine, if i turn it on via the thermidistat (TSTATCCPRH01-B), the indoor blower starts as well as the outdoor compressor and fan. House cools fine.
Now on to my current problem that first appeared last winter. With the heat pump system switched to off (for an extended period) and then switching it to heat, the thermostat (set at 72, with an indicated indoor temp at 70 or less) will show the heat indicator on the lower right. The indoor blower will turn on and the outdoor compressor and fan will kick on. The low and high pressure lines will quickly warm and the system will heat very well. House heats up quick, Yay! Well, after the target temp is reached the system will turn off as it should. This is where the problem happens, after a few hours the house temp will slowly fall and the thermostat will kick on and show the heat indicator again in the lower right and the indoor fan will turn on BUT the outdoor compressor and fan will not turn on. The thermostat will continue to run the indoor fan and show the heat indicator but the outdoor compressor and fan will not turn on again. Usually this happens after i go to bed in the evening and the fan will run all night with the temperature slowly dropping all night. I usually wake up to a cold house and then switch the system manually to Emergency heat. The emergency heat works wonderfully! The house gets warm in a matter of minutes. Thing is the system used to switch to e-heat automatically, it doesn't do it anymore (another symptom?). Over the past few days the temps were in the 40s, which are plenty high for the heat pump to work efficiently (I live in the Washington DC area).
So my question is what would cause the heat pump to heat perfectly fine for the first cycle of heat when turned on from an off position but not allow the outdoor unit to come on when its re-called after temp drops? Second is why does the system no longer switch to aux/e-heat on its own?
Just this morning i noticed something strange, the system was running as it normally does when i wake up....fan running with the heat indicated on the thermostat but outdoor unit not running and house temp dropping. Well, today is supposed to be 75degrees so i just turned it off for the day. WEll before turning it off the system showed house temp as 70 deg with a target of 72...it was attempting to get there. Approx 2-5 minutes after shutting the system completely off, i walked by the thermostat again and it said the internal temp was now 72 degrees. Is this a sign of a defective thermostat? it said it was 2 degrees cooler with the system running just ~3 minutes ago???
Additional details, again, i just replaced the indoor blower motor due to a failed front bearing, replaced capacitor. Indoor coil looks OK too. Outside, i hosed off and vacuumed the compressor unit, and changed out a weak capacitor. The contactor is aging but works perfectly fine, visually inspected it as it turned on and off. Air filter is clean and is replaced regularly. The contactor is getting 240v and the defrost board is also getting 24v.
My obvious observation is when the system is running in heat mode, not on the first start-up, the contactor is not getting a signal to activate the outside system. What could cause this condition? what would cause aux heat to no longer automatically switch on? Am I looking at a bad defrost board outside? With the indoor furnace working fine as well as all the fan controls I am inclined to say that part is working fine and the only electronics or parts are on the outside unit. I am convinced that the problems lies outside. To my knowledge, the outdoor unit has never frozen over. Last thing, the LED on the indoor board has not indicated any faults, its a solid red LED all the time.
Any help is appreciated. I've searched a bit but didn't find any answers. If I've missed a previous thread, please point me in that direction and will try what is recommended there.
The AC part of the system works fine, if i turn it on via the thermidistat (TSTATCCPRH01-B), the indoor blower starts as well as the outdoor compressor and fan. House cools fine.
Now on to my current problem that first appeared last winter. With the heat pump system switched to off (for an extended period) and then switching it to heat, the thermostat (set at 72, with an indicated indoor temp at 70 or less) will show the heat indicator on the lower right. The indoor blower will turn on and the outdoor compressor and fan will kick on. The low and high pressure lines will quickly warm and the system will heat very well. House heats up quick, Yay! Well, after the target temp is reached the system will turn off as it should. This is where the problem happens, after a few hours the house temp will slowly fall and the thermostat will kick on and show the heat indicator again in the lower right and the indoor fan will turn on BUT the outdoor compressor and fan will not turn on. The thermostat will continue to run the indoor fan and show the heat indicator but the outdoor compressor and fan will not turn on again. Usually this happens after i go to bed in the evening and the fan will run all night with the temperature slowly dropping all night. I usually wake up to a cold house and then switch the system manually to Emergency heat. The emergency heat works wonderfully! The house gets warm in a matter of minutes. Thing is the system used to switch to e-heat automatically, it doesn't do it anymore (another symptom?). Over the past few days the temps were in the 40s, which are plenty high for the heat pump to work efficiently (I live in the Washington DC area).
So my question is what would cause the heat pump to heat perfectly fine for the first cycle of heat when turned on from an off position but not allow the outdoor unit to come on when its re-called after temp drops? Second is why does the system no longer switch to aux/e-heat on its own?
Just this morning i noticed something strange, the system was running as it normally does when i wake up....fan running with the heat indicated on the thermostat but outdoor unit not running and house temp dropping. Well, today is supposed to be 75degrees so i just turned it off for the day. WEll before turning it off the system showed house temp as 70 deg with a target of 72...it was attempting to get there. Approx 2-5 minutes after shutting the system completely off, i walked by the thermostat again and it said the internal temp was now 72 degrees. Is this a sign of a defective thermostat? it said it was 2 degrees cooler with the system running just ~3 minutes ago???
Additional details, again, i just replaced the indoor blower motor due to a failed front bearing, replaced capacitor. Indoor coil looks OK too. Outside, i hosed off and vacuumed the compressor unit, and changed out a weak capacitor. The contactor is aging but works perfectly fine, visually inspected it as it turned on and off. Air filter is clean and is replaced regularly. The contactor is getting 240v and the defrost board is also getting 24v.
My obvious observation is when the system is running in heat mode, not on the first start-up, the contactor is not getting a signal to activate the outside system. What could cause this condition? what would cause aux heat to no longer automatically switch on? Am I looking at a bad defrost board outside? With the indoor furnace working fine as well as all the fan controls I am inclined to say that part is working fine and the only electronics or parts are on the outside unit. I am convinced that the problems lies outside. To my knowledge, the outdoor unit has never frozen over. Last thing, the LED on the indoor board has not indicated any faults, its a solid red LED all the time.
Any help is appreciated. I've searched a bit but didn't find any answers. If I've missed a previous thread, please point me in that direction and will try what is recommended there.