A/C humming

Sorry dougrainer, I missed the part of 5 button conctrol.

CT_WANDERER wrote:
OP Try removing the red wires to your themostat. See if the humming stop. If it is not your T-stat board the Humming should not stop. If it is your T-Stat the Humming will stop.
The 12volt power comes from the AC unit to the T-Stat on the red wire. When cooling is wanted, the T-stat send the coman signal back to the AC on the yellow wire. If the T-Stat is bad it is sending a constant signal to the AC Compresser relay. However with out the power or signal line on the T-stat. The Compresser relay should not work. So if the t-Stat is disconnected the compressor should stop if the T-Stat is bad. If the t-stat is good the compressor should be still running and your AC board could be bad. Also once you disconnect the 12 volt power wires if your compress stops, if you touch the red wires back to the terminal your compressor will start to run again. This would indicate that your T-stat is signaling the AC to run. This is the way I went and from this I replaced the Stat and my my system is working right now. Who knows maybe I was just lucky. But it only cost me $25. Check the price of replacing the AC Control Board. It will be more than $25.

HE DOES NOT HAVE THAT TYPE TSTAT, SO HE CANNOT DO WHAT YOU WANT HIM TO DO. READ my previous response to you. Besides, IF he had your type, all he has to do is turn the battery disconnect OFF and that will kill 12 volt power to the wall tstat and IF the wall tstat is the problem the compressor would stop. IF NOT, the compressor will stay running. Doug

OP Try removing the red wires to your themostat. See if the humming stop. If it is not your T-stat board the Humming should not stop. If it is your T-Stat the Humming will stop.
The 12volt power comes from the AC unit to the T-Stat on the red wire. When cooling is wanted, the T-stat send the coman signal back to the AC on the yellow wire. If the T-Stat is bad it is sending a constant signal to the AC Compresser relay. However with out the power or signal line on the T-stat. The Compresser relay should not work. So if the t-Stat is disconnected the compressor should stop if the T-Stat is bad. If the t-stat is good the compressor should be still running and your AC board could be bad. Also once you disconnect the 12 volt power wires if your compress stops, if you touch the red wires back to the terminal your compressor will start to run again. This would indicate that your T-stat is signaling the AC to run. This is the way I went and from this I replaced the Stat and my my system is working right now. Who knows maybe I was just lucky. But it only cost me $25. Check the price of replacing the AC Control Board. It will be more than $25.

CT_WANDERER wrote:

bluebarry1964b wrote:
Is it the circuit board on the wall thermostat that's no good, or the circuit board in the a/c unit itself?

I had the same problem after our trip last fall. I would hear the humming even after I tried to turn off the AC at the T-Stat. It would only stop if I turned off the AC Breaker. I checked mine out to what I felt was the T-State. Went to W-Mart and got a $25 digital T-Stat Problem gone and I have a better T-Stat controlling my AC/Furnace system.

Your problem could be in the AC board or could be the T-Stat. Best to check it out before jumpping in. T-Stat can be done for $25.00. Your AC board is going to cost more than that.

He CANNOT use any Tstst other than the 5 button CCC Dometic unit. He has NO standard wall tstat wires at all. He has a phone cable for a wire to the AC. Doug

Circuit board in AC unit. Not thermostat

bluebarry1964b wrote:
Is it the circuit board on the wall thermostat that's no good, or the circuit board in the a/c unit itself?

I had the same problem after our trip last fall. I would hear the humming even after I tried to turn off the AC at the T-Stat. It would only stop if I turned off the AC Breaker. I checked mine out to what I felt was the T-State. Went to W-Mart and got a $25 digital T-Stat Problem gone and I have a better T-Stat controlling my AC/Furnace system.

Your problem could be in the AC board or could be the T-Stat. Best to check it out before jumpping in. T-Stat can be done for $25.00. Your AC board is going to cost more than that.

bluebarry1964b wrote:
Is it the circuit board on the wall thermostat that's no good, or the circuit board in the a/c unit itself?

I'm guessing the a/c itself if your compressor is running and what I was referring to with mine.

bluebarry1964b wrote:
Is it the circuit board on the wall thermostat that's no good, or the circuit board in the a/c unit itself?

The AC circuit board, NOT the wall tstat. Doug

Is it the circuit board on the wall thermostat that's no good, or the circuit board in the a/c unit itself?

dougrainer wrote:

barnaclebill wrote:
Doug, mine does the same thing, it is a penguin with heat pump, but if I shut off at the breaker and turn it back on after 10-15 minutes it runs fine, cycles on and off but then will do the same thing again maybe 1-2-3 days later. Any thoughts? Thanks, Bill

Same relay and problem. Doug

Thank you for your quick reply, Bill