No Heat From 2010 R25 HVAC

I have an HVAC system on my 2010 Ranger 25 tug, It blows cold air, but not hot air. Any suggestions to get it to heat the boat. It is getting cold out there.

I don’t know what equipment is installed on your 2010 R25, but it may be the same as the Dometic HVAC system on my 2012 R27. It is a heat pump that operates exactly like a home heat pump except it uses sea water as the heat exchanging medium. The system has two modes, cooling and heating, just like a home heat pump. A reversing valve located adjacent to the compressor determines the mode in which the system is operating— cooling or heating. Sometimes that reversing valve gets stuck in one one mode or the other. A solenoid that physically moves the reversing valve can also fail causing it to remain in the last operating mode.

Try switching the system between heating and cooling modes a few times in an attempt to free the reversing valve. Switching between modes is accomplished by setting the thermostat in the cabin to a temperature where heat is called for by the thermostat and letting it run for a minute or two and then setting the thermostat to a temperature where the thermostat calls for cooling. This procedure can only be accomplished on a temperate day that’s not too hot or cold.

If the problem is a failure of the solenoid that physically moves the reversing valve, the above procedure will not fix the problem. The solenoid will have to be replaced. Unfortunately, there’s no way to tell which problem you have without accessing the solenoid.

If your system is Dometic, try their Global Marine Support: 1-800-730-4082

Will do, thanks

Capt Rob said:

Will do, thanks

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If you call Dometic, it will be helpful if you know the model of the unit that’s on your boat.

Hopefully someone with your model of boat will respond to clarify or add to the information I posted.

Where do I find the make and model number?

Capt Rob said:

Where do I find the make and model number?

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If the manual for your HVAC system is in the documents for your boat, you might find it there. Otherwise, you'll have to look on the equipment itself. If the HVAC system on your boat is like a 2012 R27, it is a "split system" where the compressor and air handler are in different places-- the compressor is under the footwell of the port companion seat and the air handler is in the cuddy.

Access to the compressor on 2012 R27s is gained two ways. 1) Remove the upholstered panel on the back port side of the cuddy. With that removed, there is an insulated panel that can be removed that provides limited access to the area under the port companion seat footwell where the compressor is located. There is a rectangular control box on top of the compressor that should have model and serial number information. 2) The other way to gain access to the compressor is to crawl to the forward end of the "cave"and remove the panel at the back end. Not an operation for the claustrophobic.

Access to the air handler is gained by removing the cuddy cushions. I'm pretty sure a fault in the reversing valve does not require access to the air handler.

If the model number is not in any of your boat's documents, before going to all the hassle of trying to get it off the equipment, call Dometic and tell them that you have a Dometic HVAC system installed in a 2010 Ranger Tug R25. There's a slight possibility that, if indeed a Dometic system was used in 2010 R25s, they will have records of what was installed on those boats.

I sure wish there was someone here on Tugnuts with the same model and year R25 that would know what was installed and reply. I'm just speculating that what was installed in your 2010 boat is the same as my 2012. Just understand that systems sometimes changed from model year to model year. For example, a 2016 R27 does not use the split system used on the 2012.

Got it thanks

I am in the process of buying a 2009 R25. The unit is a Dometic 16,000 b.t.u. If you place the port pasenger seat forward and look down next to the exterior of the boat , you will see a bracket holfing the seat in place. Remove the two screws and the entire seat assembly will hinge towards the center isle and under it is an opening showing the unit with the tag in plane sight.

I am in the process of buying a 2009 R25. The unit is a Dometic 16,000 b.t.u. If you place the port pasenger seat forward and look down next to the exterior of the boat , you will see a bracket holfing the seat in place. Remove the two screws and the entire seat assembly will hinge towards the center isle and under it is an opening showing the unit with the tag in plane sight.

Thanks will do

Shellback said:

……. If you place the port pasenger seat forward and look down next to the exterior of the boat , you will see a bracket holfing the seat in place. Remove the two screws and the entire seat assembly will hinge towards the center isle and under it is an opening showing the unit with the tag in plane sight.

Click to expand...

Sounds like the exact information he needs to find make and model data. Obviously, access is completely different than on a 2012 R27. Thanks for taking the time to reply.

I will try turning it off an on to see if that resets the solenoid .

What temperature range should I try that would work best for that test?

Capt Rob said:

I will try turning it off an on to see if that resets the solenoid .

What temperature range should I try that would work best for that test?

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Regarding statement #1– The solenoid is the mechanism that moves the reversing valve when that is called for by the thermostat. There is no resetting it. The solenoid either works or it doesn’t

Here’s how to get the thermostat to call for a change in reversing valve position.

Turn the system on and then look at the current temperature. Then turn the thermostat five degrees above the current temperature. That should make the system change the reversing valve to heating. Let it run for 10 minutes then turn off the system for three minutes. After that, turn the system back on and set the thermostat five degrees below the current temperature. That should provide cold air. From your previous posts, it appears your reversing valve is stuck in the cooling position.

If this confusing you, send me a PM with your phone number and I’ll try to clarify it.

I think I got it. I will let you know.
Much appreciated. Thanks.

I put it on heat , I heard someone click. It is blowing air. but no stream of water via the outside outlet.

The air temperature is 68 degrees. I set it at 75. The cabin temperature does seem to be getting warmer. But not like the heat from the engine heater.

I have a generator. I am that it would be better for me to plug in my electric heater and run the generator when anchored.

Then when plugged into shore power to run the boat havc.

I have a marine air systems, direct expansion unit. With a manual dated 9-18-07. I own a 2010 Ranger 25 Tug.

I found the problem. My AC panel was programmed to be AC only (PL1 code). I changed it to the Heat only (PL2 code). The LED lights changed from blue to red. Water started coming out of the hull outlet. It got very warm very quickly and cycled on and off correctly.

Thanks everyone for the help. Now I just have to remember to turn it back to AC only in the spring.