Trane 4dcy4060a in heat mode, after being idle for a while the thermostat calls for heat – the indoor fan starts but the compressor and outside fan do not. initially (a couple months ago) i could push on the contactor and the unit would run and keep running and the problem occurred maybe once or twice a week – mostly when the weather is 30 – 35. recently the contactor would not stay closed – no voltage on the coil. I determined that if i tap the high pressure cutoff switch the unit starts up and keeps running- until next time this happens. It has become more frequent – and is now happening more frequently – almost daily. if I tap the high temp switch when it is not running it will run for maybe 15 seconds and stop; then tapping the high pressure switch starts it and it keeps running. Is the problem the high pressure cutoff is faulty or could there be some other problem? seems odd it would be open when the unit has been idle.
Trane heat pump compressor and outside fan do not start after being idle
heatpressurepump
Related Solutions
this sounds like a problem with a thermostatic balancing valve in the shower valve. you may have to pull the cartridge and clean it out or replace it. these valves use a setup that can act strangely with time and gunk. start with the simplest thing first.
The wire on the pump is not rated to be exposed or cord connected.
You will need to mount the pump inside an enclosure such as a Hoffman box or equivalent.
Then you can terminate a raceway or cable to the enclosure and the wiring will be protected inside.
Since RV's are covered by the National Electrical Code, this will satisfy the NEC.
Good luck!
Best Answer
I think I know what is going on (mostly). the unit was running hot and it sometimes tripped when it stopped he overpressure or had a pressure spike as it turned off which tripped it. I suspect the switch does not untrip once the unit sits and the pressure drops. tapping the switch reset it. The reason the unit was running hot is that over time a mold/moss/dust layer had grown over most of the air handler; this was plugging the gaps between the fins and severely reducing the heat transfer efficiency. I cleaned this off 5 days ago and thus far have not had to tap the high pressure switch. One thing I cannot explain is that in my initial troubleshooting tapping the high temperature cutoff switch also started the unit but it only ran about 15 seconds and shut down; then tapping high pressure switch would start it.