a/c freezing up


New Member
Hi. Anyone know what to do about this....... We have a new 5th Wheel Sprinter by Keystone, our first camper. The DuoTherm a/c works great for a few hours than quits and the unit on the roof is all frozen up, like a block of ice. ??? Thanks for any help.


Senior Member
a/c freezing up

Calo, welcome to the forum. Have you checked the owner's manual in the trouble shooting section? I'm not an A/C expert, but do know that if the outside temp is lower than the inside temp setting, it will freeze up and secondly, if the filters are dirty, it will freeze up, and thirdly, if the fins on the roof unit are clogged, it will freeze up and lastly, if the freon is low, it will freeze up. I'm sure there are better experts out there than me, but perhaps some of what I have said, might help.
Good luck.... ;) :)
a/c freezing up

Take the unit back to the dealer. If you don't want to do that, remove the cover from the air conditoner. This is usually accomplished by removing four screws in the top of the cover. Carefully pull the cover off and look to see if the probe is in the cooling coils. It looks like a short tube with a wire coming out of it. This sensor is supposed to stop the air conditioner from freezing up. If it isn't in place it doesn't work. Mine was still taped to the side of the unit.

Good luck.

Ed H.

New Member
a/c freezing up

Archer is on the right track with his suggestions. Since it is a new unit, the first thing I would suspect a foreign object blocking the air flow. This could be anything from a piece of cardboard to a piece of the plastic film used to protect things during shipping.
Rlmurray's suggestoin about a misplaced control sensor is also a good bet.
I worked in the A/C business for close to 20 years and I would not open the unit myself, but take it back to the dealer. A new unit should be under warranty and it is the dealer's job to fix it, but he can't do that if you don't take it in.
a/c freezing up

Ed gave you some good advice. I couldn't take mine back to the dealer because I could never talk to anyone there to schedule a time to take it back. And I wasn't going to just drive the 3 hour trip there to be told they didn't have time to look at it because they were servicing new units they had sold to people who were going to run into the same thing I do now.

Walt Michael's RV "SuperStore" in Belleville, Michigan is a terrible dealer and should be avoided at all cost. I tried to call them again yesterday because my dash board air conditioner stopped working and the dealer I took it to said I would have to get Walt Michael's to contact the people at Workhorse to verify that it was still under warranty. After listening to the recording say, "Please stay on the line, we are assisting other customers" for 45 minutes I gave up and hung up. This has been the story for almost 3 years now.

But the dealer that I took it to found the bill of sale in the RV and called Workhorse and the air conditioner is still under warranty. Terry Labonte Chevrolet in Greensboro, NC is a Holiday Rambler dealer also and seems to have a very good RV repair facility. Good people to work with.