No power to thermostat

[jerhofer]

We are camped in Mansfield, MA in our 2013 EXT. After hooking up, I tried to turn on the AC but there is no power to the thermostat. It has been working perfectly the past six days during our trip. I checked all of the fuses both under the rear seat and under the driver's seat and did not find any that were blown. I also checked all of the circuit breakers and all is well there.

I did a search and found that one person had had an issue with the circuit breaker on the furnace. That circuit breaker is as it should be too.

The only thing different that happened today was my taking the motorhome to a place that washed RV's first thing this morning. He did a great job but was using a high pressure sprayer. Until now I did not think about covering the exhaust outlet for the furnace. Could water have entered the furnace and be causing the problem. He was not able to reach the roof very well so no high pressure water was applied to the AC unit. We drove here from just outside Philadelphia.

Everything else in the motor home appears to be working. The fuse for the thermostat also supplies voltage for the exhaust fan and it is working.

Any help would be appreciated.

[jm2]

Jerry,

start by testing the 110 VAC supply that you're hooking up to for proper ground, hot and neutral,

and then flipping the 110 VAC breaker(s) (though they may all look OK) off and then back on,

we have no firsthand knowledge of the equipment you're talking about, so,

my suggestion might be that you check in with Airstream of New England, tomorrow. they are located in Stoughton, MA, only about a dozen or so miles away from Mansfield, MA.

best of luck with the problem!

[txtwin]

Might be on the wrong track here. Assume this is the thermostat in the RV to control temp? I know this sounds super simple, but did your batteries die that power the actual thermostat? Should be 2 AA batteries, and the front just clips off.

Hope its that simple...

[Protagonist]

Originally Posted by txtwin

Should be 2 AA batteries, and the front just clips off.

Weird. My Interstate's thermostat is hardwired and runs off the house batteries. If it ran off AA cells there wouldn't be any reason for there to be a fuse for it on the fuse panel; it would be self-contained.

I'm curious how jerhofer decided that the reason the AC didn't work was that the thermostat lost power. It might be advantageous to pull the fuse and bridge across the fuse contacts with a voltmeter to see if the thermostat is in fact drawing power; if it is, it's not dead and there is some other reason for the AC to not work.

[jerhofer]

Originally Posted by Protagonist

Weird. My Interstate's thermostat is hardwired and runs off the house batteries. If it ran off AA cells there wouldn't be any reason for there to be a fuse for it on the fuse panel; it would be self-contained.

I'm curious how jerhofer decided that the reason the AC didn't work was that the thermostat lost power. It might be advantageous to pull the fuse and bridge across the fuse contacts with a voltmeter to see if the thermostat is in fact drawing power; if it is, it's not dead and there is some other reason for the AC to not work.

When I discovered the problem I was trying to check on the inside temperature. Actually, because it is cool here this evening, I would need the furnace more than the AC. But the thermostat does not light up up at all. It is dead to the world. When you push any button it should light up and then you can hit the power button to turn it on and select the mode. I don't know if the AC or furnace work but I suspect they do if only the thermostat would power up.

[jerhofer]

Originally Posted by txtwin

Might be on the wrong track here. Assume this is the thermostat in the RV to control temp? I know this sounds super simple, but did your batteries die that power the actual thermostat? Should be 2 AA batteries, and the front just clips off.

Hope its that simple...

No batteries. As Protag says, it is hardwired.

[jerhofer]

Originally Posted by jm2

Jerry,

start by testing the 110 VAC supply that you're hooking up to for proper ground, hot and neutral,

and then flipping the 110 VAC breaker(s) (though they may all look OK) off and then back on,

we have no firsthand knowledge of the equipment you're talking about, so,

my suggestion might be that you check in with Airstream of New England, tomorrow. they are located in Stoughton, MA, only about a dozen or so miles away from Mansfield, MA.

best of luck with the problem!

I flipped all the breakers on and off to no avail. I have a Progressive Industries PT30C 30 Amp Portable Electrical Management System that I use. It will detect voltage issues and it says all is well with the inline voltage. Plus everything else works in the motor home.

Amazon.com: Progressive Industries PT30C 30 Amp Portable Electrical Management System: Automotive

I found Airstream of New England on Airstream's website but it appears they only sell travel trailers. I will give them a call but I may call the factory first to see if they have any suggestions. They have been very helpful in the past.

[lewster]

You're looking under the wrong rock!!

Your Dometic CCC II thermostat is powered by 12VDC derived from the upper control board located curb side under the shroud of your roof unit. You're CCC II isn't getting any!! If you remove the inner air distribution box (watch for hidden screws ), you will see a telephone-type cable leading into a small beige (or white) plastic RJ-11 union box.

Chances are that it got overly moist and possibly shorted. Dometic conveniently provided a spare union on a different cable (probably black) leading from the roof unit (this is actually used for serial connections for up to 4 zones from a single t/stat, but you can use either one). Use a hair dryer to dry the connections, and then plug in to the other union.

If you still get nothing, you should check the 3 amp fuse located on the relay control board that is under the upper unit's shroud. If that fuse is good, locate the black and red cabled coming from the upper unit and test with a VOM for DC voltage. If none there, look at your DC fuse block for the fuse marked 'A/C'.

Have fun!

[jerhofer]

Originally Posted by lewster

You're looking under the wrong rock!!

Your Dometic CCC II thermostat is powered by 12VDC derived from the upper control board located curb side under the shroud of your roof unit. You're CCC II isn't getting any!! If you remove the inner air distribution box (watch for hidden screws ), you will see a telephone-type cable leading into a small beige (or white) plastic RJ-11 union box.

Chances are that it got overly moist and possibly shorted. Dometic conveniently provided a spare union on a different cable (probably black) leading from the roof unit (this is actually used for serial connections for up to 4 zones from a single t/stat, but you can use either one). Use a hair dryer to dry the connections, and then plug in to the other union.

If you still get nothing, you should check the 3 amp fuse located on the relay control board that is under the upper unit's shroud. If that fuse is good, locate the black and red cabled coming from the upper unit and test with a VOM for DC voltage. If none there, look at your DC fuse block for the fuse marked 'A/C'.

Have fun!

I was hoping you would respond. I will check it out.

[David O]

I had a similar problem with my new 20 ft. No power to entire trailer. Had power coming in all the way to circuit brakers and out from there. It turned out to be the gfi protector in the bathroom tripped and shut down everything!

[jerhofer]

90% of solving any problem is knowing where to look. Thanks to Lewster, I now had that knowledge. And thanks to the AC installation manual, I knew where to look for the screws. There were two on each side at the air intake. Remove the air filters prior to removing the cover. The other two screws were on each end at the horizontal vents.









As Lewster said there were a clump of wires on the curb side. Upon pulling those out I immediately discovered the problem. The phone cable that runs to the thermostat had unhooked from the receptacle. I plugged the wire into one of the receptacles and the thermostat worked. I would guess the primary reason was that someone at the factory did not properly seat them. And the very rough roads we traveled on yesterday from Philadelphia to Boston probably didn't help.





I had previously removed the thermostat from the wall mount in case it was the problem.



Many thanks to Lewster for giving me the information I needed. And now I know how that part of my AI works!!!

[Ron_CA]

Thanks for the pics. Could come in handy.

[73shark]

You should send these pictures to the Airstream folks in Jackson Center.

[lewster]

:c lap:

GOOD JOB!!!

Now I have someone I can send all of my A/C work to!!!

[Kwils25]

This thread is a great example of how awesome this forum is!


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[jerhofer]

Originally Posted by Kwils25

This thread is a great example of how awesome this forum is!


Sent from my iPad using Airstream Forums

Agreed! It was a relief that we didn't have to take the AI somewhere to get it worked on and interrupt our vacation. We have a beautiful lot in this campground and did not want to tear down.

[GloryBound]

A slight variation. My thermostat first said E1. I reset the wall unit. It now shows Zone 1(blinking) and Zone 4. Also does not recognize the furnace at all. Fan or A/C does not turn on. I checked the fuses and they all look good. Any advice would be greatly appreciated.

[73shark]

Does the owner's manual for the t-stat say what E1 means?

I seem to recall a discussion of t-stat error messages and what they meant in another thread.

[lewster]

Remove the T/stat from the wall ( pulls out from the bottom) and remove the RJ-11 plug. Wait a few minutes and reconnect.

If that doesn't work, I would next remove the inner A/C air box and look for the RJ-11 union piece. There should be another one close by.

Change the cable coming from the T/stat (provably grey) to the other union and see if works now.

Either you are not getting 12VDC to the stat from the upper relay board, or the board is bad.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[Jim Flower]

I had this same problem last week and I have had it several times before, only under extremely hot and humid conditions where the AC is working too hard. That is, I have it set too low. The fix: it's not really a fix but I blundered along and the AC eventually worked, but I do not know what causes the recurring problem. Disconnect the thermostat connections as shown in the preceding photos. Ensure the connections are dry. Reassemble. Perform a system reset. ( press zone and mode at the same time) Reprogram the thermostat. The AC will most likely not work but the fan will. Wait 24 hours and then try the AC. In my case, the AC would now work. I have no idea why but I am guessing that there is some kind of electrical gizmo that resets itself when left alone or the whole contraption has dried out. This works for me until next time I really need AC but is a pain. I am getting a little smarter by not working the AC so hard. Lewster has a real fix by adding a better seal on the AC unit. Jim


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