Dometic AC in 2016 Airstream Classic 30’

[Merckmaven]

Hi All,

I’m hoping someone can advise, need help with 2nd Dometic AC unit in AS Classic. The front unit works perfectly, but the smaller (13500) unit in the back blows out room temp air, but not all the time. If the front unit is turned on and set for around 74, and the back unit is turned off or turned up to 90 degrees, then cold air is coming out of the back unit but not really blowing like it does when fan is on. Sometimes, if the front unit has cooled down the cabin, can turn on the back unit and it will actually work, compressor, cold air blowing.

Most perplexed-obviously it’s not a Freon issue since at times it actually works. Could it be the thermostat? Welcome ANY ideas. Heat index in Texas today over 100 and have 2 large black dogs! Thanks.

[wulfraat]

I would do 3 things:

1. Turn off the front AC for this test
2. Remove and clean the ceiling-mounted filters located just under both AC units
3. Turn the temp down as low it will go in bedroom zone with AC on to force cooling action

See if you get cold air. If you do then turn on main AC with low temp to force cooling on main unit.

That will take about 5 minutes... maybe you can report back on if that helps?

[uncle_bob]

Originally Posted by wulfraat

I would do 3 things:

1. Turn off the front AC for this test
2. Remove and clean the ceiling-mounted filters located just under both AC units
3. Turn the temp down as low it will go in bedroom zone with AC on to force cooling action

See if you get cold air. If you do then turn on main AC with low temp to force cooling on main unit.

That will take about 5 minutes... maybe you can report back on if that helps?

Hi

Only thing I'd add to that is to be very sure all the vents are open. They tend to rattle shut ..... I have data on this ....

Bob

[Nelson428]

Ouch 🥵. I had the issue a few months back. Turned out my ac fan motor was going out when it worked it was cool when it didn’t it was not cool even though the unit was running. Once that was replaced all was well.

[Merckmaven]

Thanks for your suggestion-so cleaned filters yesterday. Went through your steps and waited at least 5”-air blowing robustly but still not cool.

[Merckmaven]

Thanks for your reply and suggestion- double checked and the vents are all open and the filters are all clean.

[Merckmaven]

Could you hear it running the entire time, even though it was going out? Lots of air movement and sounds like fans are normal, but air isn’t cool. Thanks!

[88Limited]

The only other user maintenance item is getting on the roof, taking the cover off and cleaning (with water) the coils. While you have the cover off (with power off the rig) check for loose wires etc.
Other than that it's time to call a tech.

[Merckmaven]

So bought a replacement Dometic Penguins 2 (13500)-does anyone think it’s worth a try to switch out the whole back AC unit or the capacitor only? Don’t know enough to determine, so welcome input. Thanks.

[Nelson428]

I replaced the whole unit. My parents have an identical unit like mine…… same issue. We replaced the av in both units. Sorry you have that issue.

[GCinSC2]

Capacitors can be tested easily with a decent multimeter.

[88Limited]

Replacing the capacitor is the cheaper option - $15 and an hour of your time. If you've already purchased another AC though...



This is a good video on how the capacitors work and how to check them.

https://www.youtube.com/watch?v=NkgxNLCrmr0

[gmattingly]

I had the same issue with our 2016 Serenity. Replaced the complete unit last year, solved the problem.

[Merckmaven]

Another question, has anyone actually replaced their Dometic AC on their AS themselves and, if so, how difficult/time consuming was it? Thanks.

[88Limited]

Originally Posted by Merckmaven

Another question, has anyone actually replaced their Dometic AC on their AS themselves and, if so, how difficult/time consuming was it? Thanks.

Once the inside surround comes off the rooftop portion of the AC is held on with 4 long bolts. Once those come out, the rooftop portion is free. I removed mine with some carpet remnants (to keep it from scratching the outer skin) a scaffold and two people to move it from the roof to the scaffold then down to the ground. Some people have rented forklifts, lulls, or made gantries to lower it from the roof. There are plenty of videos on youtube, it's not a hard job with the right planning.