Troubleshooting Heat Pump on boat

[GSS]

I have a 12,000 BTU water source heat pump on a boat. The unit heats adequately, but does not cool. Fan blows in both heat and cool cycle and the thermostat cycles in heat mode...It appears the compressor is running in cool mode, but I haven't confirmed this at the unit...I just noted the amps on the instrument panel of the boat jumps about 10 amps when this unit is on (just like it always did when it was running). Can you give me any tips on what I need to look for?

[jamesgangnc]

There's a valve in the lines that changes the direction of the refrigerant. Usually has solenoids on it. You can confirm that the solenoids are not open and that they are getting power as appropriate when you switch it back and forth between heat and cool modes. If it's getting powered and the solenoids appear to be working then the valve might be stuck. This presumes you're handy with test meters and such. Otherwise call the service guy.

[Bubba]

Look for that wet looking stuff your boat floats in called W-A-T-E-R. Jump in it. It will be cool. Bubba

[GSS]

If the valve is stuck in the cooling mode (I'm assuming it would be stuck closed) would the unit trip the on high head pressure?

[daytona°]

Is this a split system or package? Being a boater and with A/C*Heat in my boat, I never had to use the heat, but did have to add a supply air run because the unit was not breathing properly. A manufacture name and model would be nice also. Can you feel and of the refrigeration lines to see if one or the other is getting cool to the touch?

[<kjpro]

No, it&#39;d be stuck in the &#39;heating&#39; or &#39;cooling&#39; mode.

[Jeffrey Lebowski]

Wow have a nother beer, Daytona.....

Now, likely the reversing valve solenoid is stuck or burnt out or else it isnt getting voltage to change operation into the cooling mode.

[polleke]

reach in with your hand and feel the temps of the pipes.

you can be sure the compressor is pumping in correct way , but where is the hot discharge going to. and where is the unit cold etc. you should be able to find where it is going. call your son and make a drawing and together just sort it out. if in cooling mode still heating find a strange kind of valve with four pipes on it and a electrical connection check if this one is in correct position by feeling on the pipes.

[Jeffrey Lebowski]

Reach in with your hand and try feeling my f****ng pipe and I&#39;ll wallop you a good one.

[Noon-Air]

Hmmm.....water cooled on a boat...... maybe some more questions are in order.... Are the sea strainers clean?? Is the WRV functioning properly?? I do hope it has a freeze stat on the water side HX.

[jamesgangnc]

THose are good things to check but he did say it was operating properly in one mode and if there was exchanger problems it would have issues both ways.

[Noon-Air]

Wow have a nother beer, Daytona.....

THose are good things to check but he did say it was operating properly in one mode and if there was exchanger problems it would have issues both ways.

Not necessarily.... water cooled systems, especially on a boat work a little differently. Add to that, its a heat pump.... It also makes a differance if its in the Arctic where the sea water temp is 28F or at the equator where the sea water if 82F. A complete set of readings would be a good thing.

[jamesgangnc]

Mind you I agree that it would be good to look the whole thing over, no argument. But the fact that it is a heat pump using a water exchanger means if there is a problem on the water side it is not going to heat or cool. Either way if there is not water moving through the heat exchanger the water in it will very shortly get too hot or too cold to support which ever operation you are trying to do. It needs continual new water as either a heat source or a heat sink.

[Noon-Air]

Ok, so tell me why it works in heat mode but not in cooling *if* the RV is working correctly.(without a complete set of readings) Maybe the water side is a bit dirty?? Maybe the WRV isn&#39;t set correctly?? Maybe there is a bunch of algae or seaweed or jellyfish in the sea strainer?? Reduced water flow and heat transfer in heat mode will result in lots of heat output, and most probably a very cold exchanger barrel(hence the need for the freeze stat), OTOH, in cooling mode, the heat will not be transfered in the exchanger, leaving you with high head, and no cooling.

Maybe if the OP were to post a complete set of readings both before, and after making sure that the water side is clean and operating properly. Look at it this way... what will an air source HP system do with a dirty, partially stopped up outside coil do??? FWIW, the effects are more pronounced and immediate with water cooled, even with the smallest of problems.