Fan stops running on Carrier Heat Pump

[spanky1960]

I have a 20 year old carrier 2.5 ton heat pump. During a/c mode the fan will stop working while the compressor continues to hum away. Then the air coming out of the vents is hot. It does not seem to be heat related since the fan will work for about 1.5 hours before stopping. I can then go to the air handler and turn off the breakers for about 2 minutes and turn them back on and the fan will work for around another 1.5 hours. I just have to do this all day if I want it to cool my house. I had the capacitor replaced and the freon checked. Also, I noticed if I pull the fuses out of the outside box next to the heat pump and wait about 5 minutes and plug it back in the fan still does not run. It's only when I turn it off at the air handler and listen for 3 clicks and turn it back on. Last night I stood by the air handler until the air turned warm. Just before it did I heard a click and it seemed to get warmer then I heard another and another. By then the air blowing out of the handler was warm. I turned it off waited for 3 clicks (2 minutes) and turned it back on and cold air was blowing again.

The repair man came out today. He jumped the relay in the circuit board at the heat pump so the fan would not stop. He said that if the fan stopped now it would be because the fan motor needed replaced. If the fan did not stop it was the circuit board. Well the fan stayed on, but it still gets warm. I still hear a click of a relay or something in the air handler. Can someone tell me how this works? and what could be happening?

Thanks

[mattison]

Sounds like your contactor is dropping out on you. If you have a volt meter and know how to use it check for 24 volts on the control side of the contactor when it drops off. If you don't feel comfy with that then remove your t-stat from the wall and jumper R+Y+G and let it run like that for a while and see how it does.

[spanky1960]

When I tried R+Y+G at the thermostat I wasn't getting cold air, however the fan and compressor seemed to be running. I touched the bigger copper line between the heat pump and air handler and almost burned my hand. Anyway to do something like this and get Air conditioning? Or is there a way to bypass the defrost board altogether?

Thanks for your assistance!

[mattison]

When you jumpered R+Y+G you must add the reversing valve wire to the mix. It's usually "O" what are the wire landings on your stat labeled?

[spanky1960]

:wall: I really need help!

I had someone jumper the fan so it wouldn't drop out and it worked but once in a while the heat would come on. I noticed after a while neither the fan or the comperssor would come on.

I bought a new defrost board which I'm not sure I have the jumpers in the right place. I still can't get either the compressor or fan to come on.

If I push in on the relay with a screwdriver I can get the fan to come on. If I hold it in for about 10 seconds it will stay pushed in, but the compressor isn't coming on.

I also noticed one of the yellow jumpers from the capacitator to a blue ceramic device (Just looked it up on the web. It is the Compressor Thermister Starter. Looking at the Thermister and it has some burn marks around the seal... It's still hot to touch 5 min after taking it out of the heat pump) was corroded and the shield melted. I ran a new jumper. It didn't help.

Any Ideas?

I thought the new defrost board was going to work but now I can't get anything at the heat pump to work. Is there anyway to troubleshoot without the defrost board?

Would the comperssor thermister starter keep the compressor from running? It sounds like a stupid question but I just have to ask. Also what is the likelyhood that it is bad?

Thanks,
Jim :wall: