Air conditioning issue

[Knot Today]

Need some help on this one......replaced the water pump in November. Heat worked great. Now it's time for A/C and I have great flow, but the pump goes into thermal protection(?) And shuts off after a little while running. Clean strainer, ran Barnacle Buster through system.....and same thing. Water flow is great for the first part and unit is cooling. . Thanks in advance for your help!

 

[RT Firefly]

Greetings,
Welcome aboard. League City? Well y'all that'd be WARM (85F) welcome aboard.

 

[Knot Today]

Thanks. Been living aboard almost 2 years.

 

[Comodave]

What is the water temperature surrounding the boat?

 

[Knot Today]

Galveston, so around mid 70s

 

[menzies]

Need some help on this one......replaced the water pump in November. Heat worked great. Now it's time for A/C and I have great flow, but the pump goes into thermal protection(?) And shuts off after a little while running. Clean strainer, ran Barnacle Buster through system.....and same thing. Water flow is great for the first part and unit is cooling. . Thanks in advance for your help!

Do you have a air bleed line installed before the RW pump?

Could be that air is being pulled in downstream of the AC unit (between the RW intake and the RW AC pump) - usually that will give you a HI PS reading though.

 

[Knot Today]

No air bleed. I get great flow for about 10 minutes before the pump shuts down. New 1200 gph Little Giant pump (installed in November)...... should mention, it's hardwired to is own breaker. I can run if for hours without the air conditioner on and it will never go into thermal protection

 

[O C Diver]

I suspect you have an electrical problem that is reducing the voltage on the system to the point where the pump goes into thermal shut down. If you have a multi meter and know how to use it, measure voltage at the breaker for the pump with everything off. Then measure with the pump running and no air conditioning. Finally monitor voltage with both pump and air conditioning. There may be a third item which is what is pushing the thermal protection over the limit such as a refrigerator starting.

If it is low voltage, it could be a wiring issue in your boat or loss of voltage on your dock from other users or a combination of several things.

Ted

 

[Knot Today]

Ed,
Thank you. Will definitely look into that..... tried everything else! Will post results.

 

[Ski in NC]

So this is the water pump tripping? And not the AC compressor?

Water pump trips when running AC, but can run for hours with AC not on?

Something is not making sense here...

 

[DavidM]

So you have good water flow and the unit worked fine in heat mode. Now that you switched to cooling it trips even with good water flow. Sounds like the reversing valve is not working.

This is the valve that switches from heat to cool to reroute the freon. Try starting the unit on cool and tapping the valve. The valve is in the freon loop and has a solenoid and wires to it.

David

 

[Knot Today]

So you have good water flow and the unit worked fine in heat mode. Now that you switched to cooling it trips even with good water flow. Sounds like the reversing valve is not working.

This is the valve that switches from heat to cool to reroute the freon. Try starting the unit on cool and tapping the valve. The valve is in the freon loop and has a solenoid and wires to it.

David

David,
Will definitely try that, but just to clarify, the pump itself goes into thermal shutdown, not the unit. The unit just throws an E1 code (no waterflow). Not sure if the water flow would be restricted if the reversing valve was stuck?, or what could be adding a load on the pump when unit is on, vs when it is off?

 

[O C Diver]

If the pump will run without the AC unit running, it's not a problem within the AC unit as there is no valving on the water side of the AC unit, just a heat exchanger the water flows through.

Still think the thermal overload has to do with low voltage.

Ted

 

[Ski in NC]

Definitely measure run amps and volts. Ted is right, if volts are low for some reason, amps will go up and so will heat in the motor. Might just have a crappy motor or failing thermal limiter, but gots to see the volts and amps before considering that.

 

[Knot Today]

Problem solved.....I suspected a bad pump and it was confirmed. Checked the voltage to the circuit with the pump off, pump on and the ac unit on. Voltage never changed....took the pump out of the equation with a sump pump hooked up and the unit has ran for over an hour with no issues......last Cal pump I ever buy, ordering a March pump tonight.

Thank you guys for all of your troubleshooting suggestions. It's great to get some ideas from people not so close to the problem.

Calm Seas and Tight Lines!

 

[High Wire]

I’m with Ted. Running the compressor is pulling the voltage down to both compressor and pump.
Take a voltage reading at the supply to the pump with no compressor running and again with it running.
Is there a difference on shore power and on generator?
Measure the amps of the pump and compare to the nameplate for FLA, full load amps

 

[JGannon]

Air Conditioner shut down

Recently purchased a trawler with a Marine MarvairReverse Cycle AC unit. This company was bought out by Dometic and the unit is no longer being sold so there is no customer support to contact.

The unit heats OK but shuts down after several minutes in the cooling mode. Everything runs OK. There is water flowing, pump and condenser kick in, etc. The digital control unit reads “Relay Failure” when it shuts down. After turning off the circuit breaker, I can restart the unit again and everything will work fine until it shuts down again with the same message.

Have no AC experience as this is my first boat with an AC unit. Had a local AC technician stop by and he confessed he was not familiar with this unit and couldn’t figure out the problem. Am currently in the Atlantic Yacht Basin yard in Chesapeake, VA having work done. Any recommendations for a local repair technician or possible solutions would be greatly appreciated as the days are getting warmer.

 

[Comodave]

Recently purchased a trawler with a Marine MarvairReverse Cycle AC unit. This company was bought out by Dometic and the unit is no longer being sold so there is no customer support to contact.

The unit heats OK but shuts down after several minutes in the cooling mode. Everything runs OK. There is water flowing, pump and condenser kick in, etc. The digital control unit reads “Relay Failure” when it shuts down. After turning off the circuit breaker, I can restart the unit again and everything will work fine until it shuts down again with the same message.

Have no AC experience as this is my first boat with an AC unit. Had a local AC technician stop by and he confessed he was not familiar with this unit and couldn’t figure out the problem. Am currently in the Atlantic Yacht Basin yard in Chesapeake, VA having work done. Any recommendations for a local repair technician or possible solutions would be greatly appreciated as the days are getting warmer.

Welcome aboard. I am surprised that AYB doesn’t have someone that can fix A/C units. I thought they did just about everything.

 

[JGannon]

Yes. Have heard really good things about AYB. They contract out AC issues. Tech guy that stopped by unable to solve the problem. Looking for ideas on next step.

 

[Gmarr]

Recently purchased a trawler with a Marine MarvairReverse Cycle AC unit. This company was bought out by Dometic and the unit is no longer being sold so there is no customer support to contact.



The unit heats OK but shuts down after several minutes in the cooling mode. Everything runs OK. There is water flowing, pump and condenser kick in, etc. The digital control unit reads “Relay Failure” when it shuts down. After turning off the circuit breaker, I can restart the unit again and everything will work fine until it shuts down again with the same message.



Have no AC experience as this is my first boat with an AC unit. Had a local AC technician stop by and he confessed he was not familiar with this unit and couldn’t figure out the problem. Am currently in the Atlantic Yacht Basin yard in Chesapeake, VA having work done. Any recommendations for a local repair technician or possible solutions would be greatly appreciated as the days are getting warmer.

JGannon- try this guy at Dometic if he is still around- told me that there are lots of former service techs from the various companies at Dometic.


Mark Bower
Service Technician
Phone (954) 366-2778
mark.bower@dometic.com
Dometic North America, 2000 N. Andrews Ave, 33069 Pompano Beach, FL

 

[caltexflanc]

Talk to James Taylor the head honcho there at AYB and he'll find the right tech for you. Super helpful guy. Could be a reversing valve issue from the sounds of it. Or it could be reading that the pump relay hasn't triggered, or it could be something entirely different.