Dometic Marineair problem.

[wyctoronto]

It’s a 2005 16,000 BTU unit. I can’t get antifreeze from the input to the output through the unit. Have disconnected both hoses right at the unit but can’t get flow either direction. Any ideas? Does anybody have a technical support number for Dometic. Their website seems to direct me to a vendor. Thanks.

 

[Scott T-Bird]

I will be curious if you get any information. Just last Saturday, I had no flow thru my 12,000 BTU unit (1999). It seemed like the raw water pump was trying to pump water thru but I couldn't determine if there was a blockage. I was running heat just the week before. I've heard that the reverse cycle valve can get jammed sometimes when reversing from air condition to heat. But I had no problems with this up until last weekend.

 

[wyctoronto]

Mine also was working fine just before hauling out; that’s why it’s confusing !!

 

[Davidasailor26]

Air conditioning pumps are not self priming, and getting them to pull antifreeze can be tricky. When the boat is in the water the pump is usually below the waterline, so water naturally flows into it. Even then it’s often necessary to open a bleed valve to let the air out of the pump so water can start flowing. When out of the water it’s even harder to get antifreeze through to prime the pump.

If you have two people you can try having one pour antifreeze into a long neck funnel and into the intake hose, while the other person turns on the AC and opens the bleed valve long enough to bleed the pump, and then close it while AF gets circulated.

I usually winterize by myself, so I use an aquarium pump to help push the AF through. I put the pump output onto the AC input, and pour AF down a funnel while the pump and AC run. With that the aquarium pump generates just enough pressure to keep the AF flowing.

 

[wyctoronto]

Air conditioning pumps are not self priming, and getting them to pull antifreeze can be tricky. When the boat is in the water the pump is usually below the waterline, so water naturally flows into it. Even then it’s often necessary to open a bleed valve to let the air out of the pump so water can start flowing. When out of the water it’s even harder to get antifreeze through the to prime the pump.

If you have two people you can try having one pour antifreeze into a long neck funnel and into the intake hose, while the other person turns on the AC and opens the bleed valve long enough to bleed the pump, and then close it while AF gets circulated.

I usually winterize by myself, so I use an aquarium pump to help push the AF through. I put the pump output onto the AC input, and pour AF down a funnel while the pump and AC run. With that the aquarium pump generates just enough pressure to keep the AF flowing.

View attachment 235321

Thanks, but I’ve tried pumping from the unit itself both ways from the input and outflow connections. Antifreeze won’t go thru the unit.

 

[Davidasailor26]

Thanks, but I’ve tried pumping from the unit itself both ways from the input and outflow connections. Antifreeze won’t go thru the unit.

Ah, well that is strange. I think the reversing valve Scott mentioned is just for the refrigerant, not the water, so I don’t think that would be involved. I don’t have any other explanation for what might suddenly block the water flow through the unit.