AC/HEAT thermostat

[hfmckevitt]

I have a spilt ac/heat unit. (uses raw water). I’m having trouble finding a thermostat for this unit. The old was no longer working
All Honeywell stats are for heat pumps with alx heat.
They run the AC side but not the heat side.
Any recommendations
Thanks
Henry
Linda Lee

 

[PM]

I hd a local HVAC guy come replace mine. He was not really a marine AC guy although he had seen some.

He did a fine job. If I recall it was several hundred dollars. It is a pretty advanced thermostat unit.

pete

 

[oscar]

I have a spilt ac/heat unit. (uses raw water). I’m having trouble finding a thermostat for this unit. The old was no longer working
All Honeywell stats are for heat pumps with alx heat.
They run the AC side but not the heat side.
Any recommendations
Thanks
Henry
Linda Lee

Many thermostats can be programmed to do a variety of functions. The fact that it advertises heat pump/aux heat means it's capable of doing so. Download the manual for that unit and see if it can be hooked up to do less.

Without going into details I had to temporarily rig my residential smart thermostat from heat pump/aux heat to a simple "on/off" heat only. Matter of moving some of the connecting wires around.

 

[OldDan1943]

I am impressed with the marine AC/heat. Set the temp and the unit changes over as necessary. My home unit, I have to manually change over from heat to A/C.

 

[FF]

Switching from cooling to reverse cycle heating and perhaps operating a secondary heat source when its too cold for the heat pump is common on modern RV's.


Price of thermostat should be lower than boat priced.

 

[Alaskan Sea-Duction]

What brand is the unit? I have Marine Air which was bought out by Dometic. I have the three knob version for Run, Fan speed and temp. The thermostat has a long sending unit that sets in the air intake of the unit. I can still get parts, but I have to go through Dometic.

 

[gulfstar1]

You should be able to use your old thermostat as a guide to get the right style. Your standard heat pump thermostat like the honeywell will have terminals on it to switch the units reversing valve from heat to cool mode. Some marine units will use a standard heat/cool thermostat (not a heat pump stat) and the unit controls will operate the reversing valve to go to from heat to cool.
I had a mermaid reverse cycle unit on my last boat that operated this way.