AC Unit Heating, but Not Cooling

[Irishwake]

Bought a 38 carver santego which had set neglected for a few years. Aft ac unit works fine, but forward ac unit only puts out heat. It's a marine air system vr12k-h system with a 3 dial control panel. I check fuse at control at it's ok. All wires seem solid. I don't think it's a freon issue, since the actual heat is kicking out (not just air). How can I rule out thermostat in control panel? Any help is appreciated.

[RickR]

I would say if it is a heat and cold one then the reversing valve must be stuck. There is a valve in heat pump systems that reverses the flow so your chiller becomes a heater.

[speciald@ocens.]

Try banging on the reversal valve. It may be stuck. If it releases, alternate between cooling and heating until it frees up; you may be able to get it to work and save an expensive repair.

[Irishwake]

Sounds logical enough. Before I start banging on too many things.....any idea where I can get a diagram..or not to sound too dunce....what's the reversal valve look like?

[RickR]

Not sure I would not say with out seeing it but I will say you can tell it is a electric valve with wires coming out of it also look here and see what these people say about similar problems
BoaterEd - Air Won't Switch to Heat

[ShaunJ]

Originally Posted by RickR

I would say if it is a heat and cold one then the reversing valve must be stuck. There is a valve in heat pump systems that reverses the flow so your chiller becomes a heater.

Irish Wake
I think Rick nailed it, give his idea a try...
Good luck

ShaunJ

[GordMay]

Reverse cycle heat-cool units have a reversing valve that must be energized periodically to keep the internal parts moving freely. To accomplish this, switch the A/C into HEAT for a few seconds once a month.
As noted, you could try “tapping” on the valve, to try and free it up.

See Figure 1 for location.
➥ http://www.dometic.com/FileOrganizer...254-vector.pdf

Or
➥ http://www.dometic.com/FileOrganizer...-Operation.pdf

You can order parts directly from Dometic (owns MarineAir) by calling the retail sales department at 1-800 544 4881

[Irishwake]

Originally Posted by ShaunJ

Irish Wake
I think Rick nailed it, give his idea a try...
Good luck

ShaunJ

I'm beginning to suspect thermostat. Here is a similar thread from another discussion
http://marine-ac.com/forum/troublesh...does-not-cool/

I'm having same symptoms. I'll let you know how this turns out.
Thanks all for your help.