Topic: Dometic thermostat E1 - where is the control box located? (Read 1315 times) previous topic - next topic

Hi all,
My 2013 Unity thermostat has stopped controlling the fan, A/C, and furnace properly, and the thermostat on the wall is working properly AFAIK. I can step through the various modes, set temperature up and down for heating and cooling, change the fan setting Hi, Lo, and Aut, but it doesn't turn the furnace on, the A/C on, or the fan alone in reaction to the the thermostat setting. It flashes E1, meaning no communication between the thermostat and the control unit.

Did a reset, but no joy.

Today, after just leaving the thermostat on Heat for a couple of days with the LCD flashing from E1 to the temperature back and forth, a new development!

The fan/blower for the A/C ductwork in the ceiling started up, cut back off, started up again, cut back off, started up again, ran for about 45 seconds continuously while I checked to see if the blower for the FURNACE was running, ... and it wasn't.  The fan cut off when I cut the thermostat OFF and has stayed off. I tried turning the thermostat back on and still getting the same E1 to temp flash, the fan didn't come on again, and when I cycled through the Hi, Lo, Auto - still nada. <sigh>

Connections at the thermostat are tight.

I'm guessing the control box is bad with the weird fan spasms, but I'd like to take a look at it if I could only figure out where it is. It doesn't seem to be in the A/C unit on the roof.

Anyone know or have other ideas about what is going on?

Thanks in advance for any help you can give. If I have to replace the unit, I'll probably do it myself.

NEW DEVELOPMENT

After leaving the thermostat set for "furnace" with the E1 -to - 68 alternate flashing, it actually stopped flashing and just showed the temperature.

I lowered the temperature setting, and the furnace kicked in and blew hot air out the bottom vents just like it is supposed to. NORMAL OPERATION.

This morning it went back to the E1 flashing routine, and has continued flashing since. <eye roll>

Am I the only one this has ever happened to?

Doesn't want to run the Air Conditioner now, same E1 - Temperature setting flashing.

As far as trying to locate the control box, I looked behind the panel above the slide-out pantry, and there is nothing there except some cabled wiring visible. I pulled out the drawers below the wardrobe, and the power inverter is back there, and a bit of 4 - 5" ductwork for the furnace. The area under the sink seems to be just filter and the water pump. Can't see anything in the TV pop-up cabinet that looks likely.

Anyone taken off the panel above the door and seen what is back there?

Could it be behind the refrigerator, maybe accessible from the outside? Anyone replaced a refrigerator???

Am I the only guy whose thermostat started E1-ing?

Anyone ever replaced just the wall part of the thermostat and successfully got it working?

Thanks for sharing any experience you've had with the Dometic thermostat.

Have a 2012 Unity.  Just purchased a week ago so not an expert.  However was having a somewhat similar problem with the fridge. Turns out it was a tripped breaker switch in the fuse box.  It's a black panel under the passenger seat right behind the drivers seat.
If it is tripped, to reset,, just like any breaker switch push it all the way down then up again.  If there is a way other than on the outside of the fridge to control it's temp I would like to know.

Also had to learn how to turn on and off the control for A/C (haven't used the furnace yet).  Push the power button once
to get the systems attention than push again to turn on the A/C.  Just pushing the button many times in a roll might trip the breaker, not a fact,  just speculation on my part.

If your fridge is like mine and has membrane switches on the front, the increasing size boxes control the temp.

Some older models have a metal bulb mounted on the fins that slide up and down.

Sounds like your AC unit is different from mine. No switch on it.

Answering my own question in the interest of posterity...

The control board is mounted in a small metal enclosure you access from outside the RV.

You  have to go up on the roof, remove the plastic housing over the Air Conditioner, and it is located on the passenger side (right side from inside sitting in the driver's seat), behind a metal panel with an abbreviated schematic printed on it.

The printed circuit board also controls the furnace. Seems the thermostat communication problem is not from a loose wire.