yxue
Apr 25, 2008, 04:08 PM
Hi,
I have a heating and cooling system in my condo. The heating is working fine, but the A/C does not. When the room temperature is above the set temperature, the outside A/C system (compressor) kicks in and the inside evaporator coil becomes cold, but the air blower simply won't comes up whether the Fan switch is on Auto to On. The thermostat is Totaline P374-200. I did some diagnosis, and here is what I found
- If I connect R and W using a jumper, heating system will start and so does the air blower (so I can say the air blower is working)
- If I conned R and Y, the A/C system kicks in (I can hear the freon circulating) and the compressor and its fun running, and the coil becomes cold, but the air blower won't start
- If I connect R and G, the air blower does not start either.
My guess is the fan relay switch is not working. Am I right? But why it works when in heating mode. Do heating and cooling work the same way and use the same relay switch?
Appreciate any expert advice.
Thanks
I have a heating and cooling system in my condo. The heating is working fine, but the A/C does not. When the room temperature is above the set temperature, the outside A/C system (compressor) kicks in and the inside evaporator coil becomes cold, but the air blower simply won't comes up whether the Fan switch is on Auto to On. The thermostat is Totaline P374-200. I did some diagnosis, and here is what I found
- If I connect R and W using a jumper, heating system will start and so does the air blower (so I can say the air blower is working)
- If I conned R and Y, the A/C system kicks in (I can hear the freon circulating) and the compressor and its fun running, and the coil becomes cold, but the air blower won't start
- If I connect R and G, the air blower does not start either.
My guess is the fan relay switch is not working. Am I right? But why it works when in heating mode. Do heating and cooling work the same way and use the same relay switch?
Appreciate any expert advice.
Thanks