Reverse Cycle AC question...>

I have a 25 yr. old 12K Mermaid system. When cooling it works great. -20 degrees at the outlet etc. I've replaced the squirrel cage blower, and put in a Honeywell digital Thermostat. Works great in the cooling mode. Last night, due to the Cool evenings here I put it into the heat mode. Compressor was loud(er) and the fan failed to turn on. Is this the symptom of a bad reverse cycle solenoid? I haven't had the chance to adequately troubleshoot this and just reverted to my standalone West Marine heater for the evening.

Any ideas appreciated!

Thanks

Would have to believe that the thermostat did not turn on the fan and the valve is stuck halfway . Try checking your wiring at thermostat for the fan and heating. Try to power the Vale back and forth without compressor running or light tapping it while running. Values need to be operated several times a year to keep them loose.

Thanks Deckape...I'll start the diagnosis ...

Has it ever worked in the heat mode since you replaced the thermostat?


That's an important piece of information when troubleshooting.

WesK said:

Has it ever worked in the heat mode since you replaced the thermostat?

Click to expand...

Yes....Mermaid uses a simple 4 wire (home style) thermostat. Works perfectly on the cool side. Temps trigger it on and blower works perfectly. I did replace the blower this past winter, but it was an identical unit to the original so that should not be the issue...

I'll check thermostat connections first and look at the valve..

On my cruisair 16k btu, the valve makes a definite sharp click-thunk when switching, if activated when the unit is powered off. It is a 120vac powered solenoid reversing valve on my cruisair. Basically a magnetic field created by the solenoid slides the valve over when heating and for cooling the solenoid coil is off.

Heron said:

I did replace the blower this past winter, but it was an identical unit to the original so that should not be the issue

Click to expand...

Two years ago one of my home ACs had a blower motor replaced with an "identical" unit. It cooled, but when switched to the heat mode several months later no dice. The installer had miswired the unit or the wiring codes were changed. It took another technician trip to figure it out.

sunchaser said:

It cooled, but when switched to the heat mode several months later no dice. The installer had miswired the unit or the wiring codes were changed. It took another technician trip to figure it out.

Click to expand...

Interesting...
The blower is a simple 2 wire hook-up, but I'll look there too. Thanks!