Dutch Star A/C Failures

[rg neumann]

Our 2015 DS required the front Dometic AC to be replaced last fall due to a seized motor. Now the rear unit is malfunctioning and may require replacement. What is the expected life of these AC units? We are not full-timers although we keep the AC @80 degrees when we store it at home.

[Podivin]

I don't know what the 'expected' life is, but I just had to replace one of mine on my 2013. The other is still original and working fine, but the new one is SO much quieter that it's tempting to replace it just for that.

[jacwjames]

I own a 2002 Monaco.

I had to change the front motor in 2015, it started to lock up.

Last year the rear started to cause a problem. I was going to replace the motor but could not find one. Not sure if was just supply chain issues or if the motor was actually obsolete.
So after looking at options I decided to just go ahead and replace both AC's. I hope that they last but who knows. I had read that people are reporting failures on relatively new units.

[bentjm]

Originally Posted by rg neumann

Our 2015 DS required the front Dometic AC to be replaced last fall due to a seized motor. Now the rear unit is malfunctioning and may require replacement. What is the expected life of these AC units? We are not full-timers although we keep the AC @80 degrees when we store it at home.

Seized motor or seized compressor?

[rg neumann]

The motor hummed but I rotated it and it then ran for the balance of time. However, the compressor didn't come on (the amps. remained @ 3). An hour or so later the motor still ran but no cooling occurred. Guess a call to a mobile mechanic is required.

[WILDEBILL308]

Originally Posted by rg neumann

The motor hummed but I rotated it and it then ran for the balance of time. However, the compressor didn't come on (the amps. remained @ 3). An hour or so later the motor still ran but no cooling occurred. Guess a call to a mobile mechanic is required.

Try this, turn your AC off at the thermostat. Turn the thermostat off. Remove the front of the thermostat and see if there is a fuse in side. If there is remove it (I also check it with a meter) then replace it, now turn everything back on.
You can spray some light oil on the fan bearings and sometimes that will help extend the life.
Bill

[Calpop45]

Re: humming but no cool. Check run/start capacitor. Simple to do and easy to replace. Source: SupplyHouse.com

[bentjm]

Originally Posted by Calpop45

Re: humming but no cool. Check run/start capacitor. Simple to do and easy to replace. Source: SupplyHouse.com

+1. Check the capacitor.

[Dutch Star Don]

From late 2013 to early 2015 Dometic had a huge number of failures from poorly soldered circuit boards. When we bought our 2014 DS, there was another on the lot that was identical, but a different color. That coach had both Dometic units fail.

Did Dometic step up.....NO!

[Injuneer]

I've seen 40+ year old Dometic rooftop AC units still humming along fine.
I can guarantee that probably more than 85% of all total replacements are not needed. Repair shops make far more money on new ones, rarely have a trained HVAC tech on staff, and they usually don't warranty repairs more than 5 miles and 5 minutes. Motors can be retrofitted or rebuilt if a direct replacement cannot be found. Capacitors can be replaced. Control boards can be fixed. Thermostats can be replaced or retrofitted. The only reason I'd ever replace one is if the compressor shorted or opened, and that is a very rare occurrence.

[Pelledan]

Checking the capacitor is quick and easy. Shut down all power and remove the two wires from the capacitor. Take an insulated screwdriver and short across the two terminals to discharge any power that may be held in the capacitor. Take a multi-meter (a cheap $10.00 one with a resistance selection will do) and set it for resistance check. Cross connect the two meter wires for continuity and adjust continuity for 100% scale deflection. Take one meter wire and hold to one of the capacitor terminals, the look at the meter as you touch the other meter wire to the capacitor's other terminal. If you get no needle deflection on the meter, the capacitor is open and no good. If you get a sustained meter deflection, the capacitor is shorted and no good. If you get a quick "blip" deflection where the meter needle rises and falls (it will do this very quickly), the capacitor is good and your problem is elsewhere.

Dan

[dp7]

Originally Posted by rg neumann

Our 2015 DS required the front Dometic AC to be replaced last fall due to a seized motor. Now the rear unit is malfunctioning and may require replacement. What is the expected life of these AC units? We are not full-timers although we keep the AC @80 degrees when we store it at home.

My rear dometic Penguin II lasted 8 months. The front one lasted 10 months.

[bentjm]

Another consideration is the quality of your incoming power. Low voltage at a campground where I parked my coach for a year before we retired and started traveling fried the compressors in both my Penguin IIs. They had been installed by the previous owner a year and a half earlier.

I blame myself for not checking the voltage.

I replaced both units myself and installed a Hughes Autoformer. No problems since then.

[DrPhil]

I've always heard that running the AC when the voltage is low is very hard on an AC and then will of course shorten the life of the compressor. Not sure if this is true or not, but lots of campgrounds have subpar electrical systems, and this is why I always use an autoformer.