Dometic A/C troubleshooting

reset the thermostat by pushing the on/off and plus button see if it comes on

mis-post...

Thanks for the tip. Tried that and cooling performance still stinks. I just hope it holds out another day and I'll get it in for service ASAP.

Sounds like a ducted unit. Wonder if something went wrong in that ducting.

If you c an hear the hum of the compressor running, the unit has lost its 410a charge and will have to be replaced under warranty. Doug

j-d wrote:
Sounds like a ducted unit. Wonder if something went wrong in that ducting.

Yeah. I'm not sure - even opening up the vent on it that directs all the cold air out of the unit instead of the ducts had about a 71 degree air temp when it was in the mid 80's yesterday. The thing used to work really well and would freeze you out at night earlier in the summer.

Do they develop leaks or could it be a sensor problem?

Check the easy stuff first. Filter- done, temperature differential- with an inferred temp gun check the inlet air and outlet air. It should be 15-20 degrees difference. If not, remove the vent cover (4 screws) and make sure the divider baffle between the inlet and outlet sections is sealed good. If all of that is OK, then you start looking for electrical/mechanical problems.

itguy08 wrote:

j-d wrote:
Sounds like a ducted unit. Wonder if something went wrong in that ducting.

Yeah. I'm not sure - even opening up the vent on it that directs all the cold air out of the unit instead of the ducts had about a 71 degree air temp when it was in the mid 80's yesterday. The thing used to work really well and would freeze you out at night earlier in the summer.

Do they develop leaks or could it be a sensor problem?

Yes, they can have leaks. Possible it is a freeze sensor but very unlikely. AS I stated, IF you hear the hum of the compressor or go up on top and put your hand on the compressor and it IS running, there is no other thing to do but replace the upper unit. Doug

Thanks for the tips - I took a look at the vent cover and all seems good up there - the duct holes look sealed and it looks like nothing is missing.

Don't have an IR thermometer but taping out outdoor thermometer got it to a low of 69 yesterday when it was in the low 80's.

Today it's 83 outside and 79 in the trailer with the AC running since about 9AM. Something's not right as we're in the shade and it can't keep up. Luckilly it's under warranty so when we get back a call to the dealer will be the 1st thing on Tuesday.

Thanks all!

My Dometic 13.5k A/C just died over vacation 2 months ago. Worked okay then suddenly wasn't cooling much if at all. I climbed up on the roof and saw oily stuff all over the compressor which was still running. Something sprung a leak. Just replaced the unit myself since these things are pretty much non-serviceable. I hope your luck was better than mine.

Joel