Reverse Cycle Heat AC

Stormer · #1 11-12-2003

Help please -

I have a cruisair reverse cycle unit that is about 15 years old. It has worked well since I''ve owned the boat - till recently. The AC works fine - but the heat has stopped working. I''m sure it''s not a thermostat problem since I replaced the thermostat sensor and the unit worked well after that.

Any thoughts anyone?

Thanks.

GordMay · #2 11-13-2003

I’m not certain I understand your question - “you replaced the thermostat sensor, & the unit worked fine”.
I’m going to presume that, having replaced the thermostat, your unit still does not heat ???

Reverse Cycle Heat/Cool units have a Reversing Valve, that must be periodically energized, in order to prevent it from seizing up. To keep the Reversing Valve operating freely, switch the A/C to Heat mode, for a few moments, at least once a month.

You might be able to “Free-Up” a seized Valve, by gently tapping it, while in Heating Mode.

The less likely problem with the Valve could be a broken coil. You can test this (with ALL POWER OFF) by removing the two (2) Reversing Coil Wires from the terminal strip (in the control box - not the thermostat), and measuring for continuity with your Ohmmeter . The coil should read near Zero Ohms.

Good luck, & regards,
Gord

Stormer · #3 11-16-2003

Sorry to be unclear Gord -

Several years ago the thermostat went bad - the unit still produced heat at that time...it just didn''t shut off (kept throwing off heat). I replaced the thermostat and unit did stop producing heat when the cabin got warm enough. My problem now is that it doesn''t heat at all (but it WILL cool). I''ve tried running the unit and switching between heat/cold - but it still doesn''t work. How do I identify the correct wires in the control box? There are several of them? Thx.

Matt

Could you be a bit more specific as to you comments? How can I "energize" the system? Does an HVAC guy have to charge it somehow?

Stormer · #4 11-16-2003

Also, what is the location of the valve?

GordMay · #5 11-16-2003

The reversing valve should be located with the compressor, and might have a black cabtire cable (like extension cord) running to the control box. In any case, the valve only has two wires.
Try searching the Cruisair (note spelling - no ''e'') site for your specific model. I think they have wiring diagrams.