Dometic penguin thermostat???

[larry b]

I have a roughly 1996 Dometic Penguin AC unit. This unit works great but tries to keep an exact temperature and the compressor only turns on for 1-2 minutes and then shuts off for roughly one minute. This only happens when the AC unit can keep up with the desired temperature easily.

My question-how do i open up the temp range between turning off and turning back on? I haven't measured this but my guess there is no drop in degrees now. Is there an external thermostat I can wire in?

Any help? this weekend i couldn't sleep because i kept turning up and down the thermostat to keep the AC on for the family.

Thanks
Larry

[larry b]

Any ideas?? Just throwing this back out there looking for suggestions!

Thanks
Larry

[overlander63]

Move the sensor for the thermostat out of the draft of cold air. You can also try putting a rubber or vinyl tube over the sensor.

[Silver Hawk]

When I had mine installed I got a external (from A/C) thermastat installed. Put in the living room away from draft. Works great.

[larry b]

Thanks i will give it a try that is a very easy fix
I usually over complicate things and forget the K.I.S.S method.
Hope it works

Thanks for the idea

[perryg114]

Remove the cover and pull out the sensor tube and run it out the side of the shroud so it sticks out into the room air. Most AC units have a real leaky poorly designed air box that leaks cold air into the intake where the sensor is.

Perry

Originally Posted by overlander63

Move the sensor for the thermostat out of the draft of cold air. You can also try putting a rubber or vinyl tube over the sensor.

[ggoat!!!]

The thermostat, if mechanical like most older units are, is easily adjustable. Disconnect power from the trailer. Take the inside a/c cover off, then remove the metal cover around the thermostat itself. On the front of the thermostat itself you will see a small hole just to the left of the main temperature adjustment knob/pot. Inside this tiny hole will be a tiny flathead adjustable pot. A jeweler's screwdriver is used to adjust it. It will be labeled with an arrow pointing down with the words "colder" embossed very small in the metal. Turn in the direction of the arrow for increased sensitivity of the temperature control; i.e., the compressor will kick in at an earlier spot in the temperature control's range. I had this problem with mine; even with the control set to maximum cool, it would only kick on if it was warmer than 80 or so degrees and was miserable. A couple turns of the internal thermostat's adjuster and the trailer is like a meat wagon...literally freezing in there if I want it...and I DO! Love it. And, no freezing up.

[larry b]

Thanks all for the useful info.

ggoat the problem is not with the ac not turning on it cycles on and off to often with little or no temperature change in the camper. When its hot or in full sun the ac unit cycles normally. Its only at night when the ac unit can easily keep the desired temp. I am thinking the position and draft sounds logical. I just got in from moving the tube , still inside the ac shroud but moved away from the metal frame. I also put a loose fitting plastic tube over the thermistat tube. I will give this a try this weekend. If this doesnt work i will try moving the thermostat outside and adjusting the pots. Thanks again for the help

[perryg114]

The thermostat is designed such that when the temp gets close to 70 degrees it won't turn the AC on even if it is set to full cold. Move the sensor then play with the screw. I have thought of putting a manual overide on mine so the compressor comes on when the switch is on. That thermostat is just a bimetal spring in there with some contacts on it and as ggoat says, it is probably adjustable.

Perry

[larry b]

Well i tried it tonight and seems much better. The AC unit compressor doesnt cycle on and off nearly as much as it used to. Moving and putting the termostat tube in a plastic tube seamed to do the trick.

Thanks for the help

Larry