Exterior heat pump, Carrier Mdl 38YCC036340, cycles on and off when thermostat set on heat and fan on auto with ambient interior temp at 65 deg and thermostat set at 72 deg. Emergency heat function working properly. In Emer Heat function, heats house to desired temp and keeps it there. I have turned the heat pump off and am relying entirely on the emergency heat function to heat the house. What can I do to test the heat pump and or the thermostat? Thanks
It sounds as if you you have a low charge of refrigerant, r22. When the unit comes on outside, the outdoor coils become the lowside, there is a low pressure switch that is tripping out contactor protecting the compressor.
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If your thermostat is being used with an electric heating system and the fan does not start in heating mode on auto; remove the thermostat from the subcase on the wall and check for a switch on the back of the thermostat. A lot of electronic thermostats have a switch on the back that says electric/heat pump and gas/oil. If you have electric heat or heat pump you need to switch it to this side. Usually this is set at the factory for gas/ oil. Gas/oil furnaces have built in means of bringing on the fan and electric/ heat pumps are brought on by the thermostat.
if you have a gas or oil furnace then the limit control is probably bad. If you have electric heat or a heat pump then the sequencer is probably bad. But first make sure the thermostat is not set to "FAN". The thermostat must be set to "AUTO". Many systems have a time delay on the fan to capture the remaining heat after it completes a heating cycle. Usually several minutes.
It's hard to answer that question because there are so many variables. First I would look at the thermostat and see what manual settings are available. If it's a non programable there should be a switch that goes from heat to cool,one position for fan on , one for off, and one for auto. Set the heat/cool switch to heat. the fan on ,off and auto to auto. Then turn thermostat control up so it's above surrounding temperature.This should cause the heater to come on. If that doesn't work you may have problems with heater or thermostat. If it a programable t-stat I will need more information,such as name brand,model,etc. Hope this helps. Thanks.
If you have a standard thermostat the fan switch is for the air handler only. It completely over rides the thermostat for most settings. Now lets see this is what I'd expect: fan switch on Indoor fan runs all time Fan switch auto Indoor fan only runs when thermostat is set to cool or heat and the thermostat is turned up above room temp for heat or below room temp for cooling. In both of these modes the furnace blower comes on and stays on til the room temperature is satisfied. The outdoor unit only comes on for AC the out door unit will not come on for heat or the "on" setting on the thermostat. See exception 1 & 2 below...
Exception 1- (in a heat pump the out door unit runs in both heat and cool mode
unless it has emergency heat turned on then it will not come on outside
in the heat mode, and depending on the type of heat pump and furnace or
air handler it is). A heat pump thermostat usually has "backup heat" and an "emergency heat" setting switch on the thermostat. Exception 2 - On some thermostats they are made to cycle on the heat if the temperature reaches a preset temp (around 50'f usually but definitely by 40'f). This mode prevents freezing when if instance the homeowner is away or while the home is under construction. In this mode the fan inside can run but the heat usually comes on with it. Exception3 - On some electric furnaces the heating strips may be individually controlled and thus not all come on at one time. This may give the feel of no heat especially if the room is cold.
Now there may be other exceptions but Ive tried to give you a heads up on some of the most common ones. If you need more help please post more specifics about your unit/system as to for sure what switches are set to what setting and what is happening with each. My first though was that maybe your system is OK and you needed to know if the thermostat was working properly.
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you need to go oside and look for a red reset button on the unit. you tripped the high ressure switch when you let your filter get that dirty. go check on this and when your done if it still is not working then ask me more.