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I am diagnosing a heat pump. The customer said it worked great during the cooling season, but when she turned the thermostat to heating, the thermostat started smoking. I took off the cover to the thermostat, jumpered the red with yellow, ac worked great, then jumpered red with white, and started sparking alot so i couldnt keep it that way because i felt the transformer and it was getting very hot. Please help! Any ideas??
 

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Techseabreeze
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Shorting at Thermostat

If your transformer became very hot it most likely took out the windings. Transformers should have a 3 amp. max. fuse inline with the Red wire just as it leaves transformer to prevent something like this from happening. Sounds to me you are needing to repair wiring, thermostat and replace the transformer. Better get some fuses and prevent the possibility again as you find the reason for thermostat shorting. Good Luck
 

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Energy mover
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if your trans is working fine between r and Y then it's not likely the transformer. if it was it would be doing that with r to g, r to y and r to w. it sound like there is a short in the W wire shorting the circuit to ground.
 

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Is it a Rheem or Ruud heat pump? If you jump R and Y and got AC without energizing the reversing valve you will have to get 24v to your reversing valve for heating mode. A heat pump thermostat energizes Y on any initial call for cooling or heat. The W terminal is the second call for heat.
 

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I have a Dayton heat pump, made by Rheem/Ruud (I think) and have recently installed a new Tempstar touch screen programmable thermostat. The thermostat is rated 2 heat and one cooling. My primary heat source is oil forced air upflow furnace with the heat pump added later with a fossil fuel kit installed. The system has worked great with a Maple/Chase 9721 programmable thermostat for years but the clock portion of the screen lost several of the numbers so I had to replace it. Everything works fine except I can't get the reversing valve to switch to heating. When the stat calls for heat the furnace comes on. I have all the schematics, thermostat, fossil fuel kit and heat pump. What would you charge me to review the schematics and provide me a solution to my problem? I could Fax or mail copies to you. There is no rush, although I am spending more to heat the house than I need to.

Thanks,

Joe Clemmons
 

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i am diagnosing a heat pump. The customer said it worked great during the cooling season, but when she turned the thermostat to heating, the thermostat started smoking. I took off the cover to the thermostat, jumpered the red with yellow, ac worked great, then jumpered red with white, and started sparking alot so i couldnt keep it that way because i felt the transformer and it was getting very hot. Please help! Any ideas??
thats basice service work man go home
 

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well if you did not take out transformer, If you are trying to get the heat pump to work and you get the ac to work in cooling mode by jumping r to y then you need to jump r,g,y,(o,b) connections. But it does sound like the short is on the w connection so the wire is either shorted or you have bad relay. Put a fuse in line and try again.
 

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Take the thermostat wires off at the unit then check the white to ground. If you get continuity it is in the wire if not it is probably in the upstream wiring or controls. I have seen people install new t-stats and run a screw into the wires.
 

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I have a Dayton heat pump, made by Rheem/Ruud (I think) and have recently installed a new Tempstar touch screen programmable thermostat. The thermostat is rated 2 heat and one cooling. My primary heat source is oil forced air upflow furnace with the heat pump added later with a fossil fuel kit installed. The system has worked great with a Maple/Chase 9721 programmable thermostat for years but the clock portion of the screen lost several of the numbers so I had to replace it. Everything works fine except I can't get the reversing valve to switch to heating. When the stat calls for heat the furnace comes on. I have all the schematics, thermostat, fossil fuel kit and heat pump. What would you charge me to review the schematics and provide me a solution to my problem? I could Fax or mail copies to you. There is no rush, although I am spending more to heat the house than I need to.

Thanks,

Joe Clemmons
R u sure you got the heat pump wired right. Sometimes u gotta have the blue wire instead of orange. Try heat when reversing valve is energized.
 

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I can't comprehend that this is a transformer problem...truth of the matter is..this is troubleshooting 101. any real tech could diagnose this problem in less than 5 min with an ohm meter. After you change the transformer and it still won't work, then call a tech. (hint....aux heat relay coil or wire)
 

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I am diagnosing a heat pump. The customer said it worked great during the cooling season, but when she turned the thermostat to heating, the thermostat started smoking. I took off the cover to the thermostat, jumpered the red with yellow, ac worked great, then jumpered red with white, and started sparking alot so i couldnt keep it that way because i felt the transformer and it was getting very hot. Please help! Any ideas??
You need to understand how a heat pump works and get the appropriate thermostat that can control it or put 3 relays. R ,b/o ,y and g should all be energized during a heat call on the heat pump.
 

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HEAT PUMP NOT COOLING.


Indoor unit issues – If the heat pump is running, but pumping warm air, and the thermostat checks out, you may be low on refrigerant or have a faulty reversing valve. If there is no airflow, check your power switch or circuit breaker.
Dirty/clogged filter - A clogged filter or other blockages in the indoor blower can result in air becoming obstructed and weak/no airflow into your home. Inspect and clean/replace your air filter if necessary.
Dirty/clogged outdoor coil – Things like cottonwood and other dirt and debris can build up on your outdoor coil and reduce its ability to transfer heat effectively. The outdoor coil should be cleaned during regular system maintenance.

Thermostat settings - Start by checking to make sure the thermostat is set properly. If it is on heat mode or constant fan, it may be operating, but blowing warm air. Adjust the thermostat so it is set to cool or the “auto” setting. Continue by decreasing the temperature by a few degrees and monitoring for a change in room temperature.
Outdoor unit issues – Be sure the outdoor unit is running. As previously described, check your circuit breaker, and visually inspect for signs of the outdoor unit freezing, which may be a clue you have low refrigerant charge.
 

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I am diagnosing a heat pump. The customer said it worked great during the cooling season, but when she turned the thermostat to heating, the thermostat started smoking. I took off the cover to the thermostat, jumpered the red with yellow, ac worked great, then jumpered red with white, and started sparking alot so i couldnt keep it that way because i felt the transformer and it was getting very hot. Please help! Any ideas??
 

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Start by checking to make sure the thermostat is set properly. If it is on heat mode or constant fan, it may be operating, but blowing warm air. Adjust the thermostat so it is set to cool or the “auto” setting. Continue by decreasing the temperature by a few degrees and monitoring for a change in room temperature.
 
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