Leak from AC heat pump housing

[danlehosky]

We just brought our new 2012 25fb flying cloud and I walked into it this morning only to see water on the floor. I looked up and noticed that it had dripped from the ac heat pump housing. We are keeping the trailer warm running on auto which I assume means the hp is doing the work. Any ideas?
Best
Dan

[SteveH]

Did you have rain over night, or do you think it is condensation from the unit?

If rain, there is a gasket between the unit, and the top of the trailer. If condensation, there is a drain for that which sometimes gets plugged from insects or mold and muck like the home AC drains.

[dznf0g]

Correct me if I'm wrong, but I THINK that the AC drain hose only drips when AC is on. When heat pump is on, I believe, the condensation produced during the defrost cycle, just runs off the roof.
If that's true, I would think the seal between the roof and bottom of the AC unit (outside) is allowing water to run in. Mine had a small pinhole leak there and I sealed it from inside around the perimeter of the roof opening. There was a small void in the factory seal job.

[SteveH]

Originally Posted by dznf0g

Correct me if I'm wrong, but I THINK that the AC drain hose only drips when AC is on. When heat pump is on, I believe, the condensation produced during the defrost cycle, just runs off the roof.
If that's true, I would think the seal between the roof and bottom of the AC unit (outside) is allowing water to run in. Mine had a small pinhole leak there and I sealed it from inside around the perimeter of the roof opening. There was a small void in the factory seal job.

Yes, I think you are right, normally. But, look where the OP is located and think about the humidity level he has to deal with.

[Silver Goose]

Originally Posted by dznf0g

Correct me if I'm wrong, but I THINK that the AC drain hose only drips when AC is on. When heat pump is on, I believe, the condensation produced during the defrost cycle, just runs off the roof.
If that's true, I would think the seal between the roof and bottom of the AC unit (outside) is allowing water to run in. Mine had a small pinhole leak there and I sealed it from inside around the perimeter of the roof opening. There was a small void in the factory seal job.

That's exactly how mine works... A/C condensation drains to the wheel well via a tube, H/P condensation runs off the roof. During the periodic defrost cycle in H/P mode, the unit essentially switches to A/C mode for a few minutes except the inside blower stops. Being in a relatively dry climate, I haven't experienced this, but expect in a high humidity area as SteveH pointed out it would seem reasonable that condensation would form on the inside coil during defrost, then when the blower kicked in, it might blow some water into the ceiling housing. that might account for a few drips at the end of the defrost cycle. If its more than that, I would be inspecting the seals for a possible leak or a plugged up drain tube.

BTW, the 1st time we used the H/P, I woke up in the middle of the night and immediately became aware that the compressor was running on the roof, but the blower wasn't. In my half awake state I thought that couldn't be good, so I manually switched to furnace. After breakfast I was reading the book and discovered the paragraph about the defrost cycle. I think it also says "Defrost" will display on the CCC, but have never looked.

[Schu]

Dometic has been confirmed condensation will come to the inside to drain out of tube. How do you have vents set?

[danlehosky]

Thanks, I have the side vents partially open, the front vent about 1/3 open and the back vent awfully open, I have the thermostat set to run on all auto including the fan.

[Silver Goose]

Originally Posted by Schu

Dometic has been confirmed condensation will come to the inside to drain out of tube. How do you have vents set?

Schu, are you saying the heat pump condensation should be directed to the pan drain and drain line and not run off the roof? The A/C condensation drains properly through the wheel well, but the H/P condensation has always run off the roof, never through the drain and I had assumed this was normal. If you believe it should not run off the roof, I will investigate why it is the next time I find a reason to get up there.

My ceiling shroud has a pair of vents facing fore and aft, both open. I've not experienced any drips inside.

[dznf0g]

Originally Posted by Schu

Dometic has been confirmed condensation will come to the inside to drain out of tube. How do you have vents set?

Yes, but as Steve says, only during the defrost cycle.
I suppose, Steve, you could be right, that there is enough humidity to have a significant drain off into the pan after a defrost cycle. I have never experienced that (that I am aware of), but it's possible.