Dometic AC compressor not starting

[jfschmitter]

I have recently installed a new Dometic 15K Duo Therm AC unit. Normally the compressor starts within 10 seconds after the blower, but occasionally it will not start and the blower will turn off after a minute or so and then cycle again after a few minutes. The compressor may start on the second attempt or it may take 3 attempts. This is very intermittent and there may be a few days between occurrences. When I have checked the voltages it is been between 118 and 120. Should I add a starting capacitor? Are there any other suggestions?

Thanks

[Herk7769]

Originally Posted by jfschmitter

I have recently installed a new Dometic 15K Duo Therm AC unit. Normally the compressor starts within 10 seconds after the blower, but occasionally it will not start and the blower will turn off after a minute or so and then cycle again after a few minutes. The compressor may start on the second attempt or it may take 3 attempts. This is very intermittent and there may be a few days between occurrences. When I have checked the voltages it is been between 118 and 120. Should I add a starting capacitor? Are there any other suggestions?

Thanks

If new I would call Dometic. It should be under warranty.

[Witch Doctor]

It sounds more like a stat problem, even if the compressor did not start and was out on internal overload, your blower would still stay on. Because your blower is shutting down it could also be the circuit board inside the unit, but I think more then likely it's the stat. Is your breaker tripping? If no then it's not an overload or equalization problem. It's a stat or board problem in the unit.

[jfschmitter]

No the breaker is not tripping. The stat and control unit are also new. This is under warranty, but I want to be sure that it will be covered prior to calling a mobile service tech to diagnose the problem.

[Witch Doctor]

I would think that it would be under Warranty, in fact I think they are under warranty for 2 years, the problem will be for him to try and make it happen when he is there. Also some stats are bad right out of the box. If you put the stat on that would not be under warranty but your A/C would be.

[jfschmitter]

I have replaced the thermostat and control kit and still have the same issue. The other problem is that this occurs only at night when the outside air temp drops. I am in florida, so it is not that cool at night. Any other suggestions?

[Oaklevel]

Were are you running it????? At home with a long extension cord??? Or with at least a 30A cord & 30A Breaker

[jfschmitter]

I have a 30 amp service at the campground. I have checked the night time voltages for any drop, but it stays steady at 119 to 121.

[TURBS]

Originally Posted by herk7769

If new I would call Dometic. It should be under warranty.

2 year warranty for dometic a/c

[jfschmitter]

I have called Dometic and they gave me the number for a mobile AC tech. I will post the information when I get an answer.

[hrepich1]

I have a new Dometic air conditioner with exactly the same symptoms. Dealer replaced wall thermostat and control board under warranty to no avail. Fails mostly at night where the temp differential is small. Counted fan coming on and off 20 times without compressor coming on. Heat of finger under the stat will turn the compressor on. Taking it in again. I think it is in the program chip in the wall stat.

[jfschmitter]

I had tried 2 Thermostat and control box assemblies and had the same issue with both. I contacted Dometic and they sent me a T stat and control box for a unit that has heat strips. Although I don't use the heat strip, this control is different that the original. This works great! Functions as it should. I think they have a design flaw in the other style controls.
Joe S.

[hrepich1]

Thanks, they replaced the t stat with a white one, used to be black, both are LED read outs with buttons and a circuit board behind in a new 2013 Winebago.