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Topic: How to repair your Dometic 4 button thermostat (Read 4060 times) previous topic - next topic

How to repair your Dometic 4 button thermostat

For those with thermostats that still work but don't respond to buttons well, here's the fix, no soldering required. 

It would take multiple button pushes to get my thermostat to switch mode, and it got frustrating.  I've heard of disassembling the switches to clean them periodically but wanted a better fix.  So...

An order to Mouser Electronics for new switches, I bought five @ $1.22 each.  They are exact replacements.
Mouser number    PVA10AH2
Mfg. PN:              PVA10AH2
These are DPST momentary 23mm pushbutton switches.

Turn thermostat off.  Remove the cover from the thermostat, it snaps on.

Remove the screws that hold the circuit board, unplug the cable from it.  This is an electronics board so treat it gently and ground your body (touch something substantial and metal), don't shuffle over the floor in wool socks holding it etc. to eliminate any static charge before touching it. 

Set it on a padded surface on the table and look at the switches. Break out the reading glasses.  Using a small screwdriver or knife tip, you can release the retaining clips that hold the components of a switch together.  Release clips, withdraw the top, spring and contacts, noting how they are inserted.  They will only go in one way.

Now, take one of your new switches and do the same.  Use the new parts in the old switch housing and snap the switch back together. You've just rebuilt the switch. 

Five minutes max.  It sounds far more complex than it is.  There is a spring in the switch that can pop out, really doesn't matter though as you use the new spring. Repeat as necessary for any other hinky switches and carefully reassemble the thermostat.

I didn't take pictures of the procedure and it's pretty self explanatory once you look at it but can and will post pix if necessary.  I enjoy this fix on a daily basis and hope you do also.

Chuck

"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: How to repair your Dometic 4 button thermostat

Reply #1
Chuck,, it shows 23mm on the website under that part # and they are soldered???
John H
Coachless, now use aircraft.
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: How to repair your Dometic 4 button thermostat

Reply #2
I did mine a few years back, took the t/stat apart cleaned it, and if my memory serves me correctly, turned the contacts over. As Chuck said the contacts and springs are SMALL, I put mine on a white pillow case make the little parts easier to see, a pair of tweezers are handy too.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: How to repair your Dometic 4 button thermostat

Reply #3
Chuck,, it shows 23mm on the website under that part # and they are soldered???
John H

Good catch John, they are 23mm.  They have pins on them for soldering into a circuit board but you won't be using them.  Chuck
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: How to repair your Dometic 4 button thermostat

Reply #4
My switches were acting eratic and I sprayed the contacts with corrision x and they are acting normal for now. Thanks for the repair procedure, if they act up again I will try your repair.
Felix and Gail Mathieu
99 U320
Jeep Liberty CRD
Build number 5522

Re: How to repair your Dometic 4 button thermostat

Reply #5
same here Chuck, I took them apart as you said and using a fine brush justgave the contacts a touch with Corrosion X and all is good now. I bought 2 cans when we were at Xtreme and I only have 1 left. Good stuff and will have to see if I can get it closer to here.
John h
Coachless, now use aircraft.
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: How to repair your Dometic 4 button thermostat

Reply #6
 
same here Chuck, I took them apart as you said and using a fine brush justgave the contacts a touch with Corrosion X and all is good now. I bought 2 cans when we were at Xtreme and I only have 1 left. Good stuff and will have to see if I can get it closer to here.
John h

Good deal, even better.  Zero parts cost and it's fixed.  Recycling at its finest.
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: How to repair your Dometic 4 button thermostat

Reply #7
Howdy Chuck,

  I recently ordered these switches from Mouser.  Replaced contacts following your intstructions..
Thermostat works like new. We sure were getting tired of pounding on the controller!!.Its a great and inexpensive fix.  Thanks for your work on this..I'm bumping your karma up a notch!!!
Dave Abel
Dave and Nancy Abel
'00 U320 36' WTFE  Build #5669
'10 Jeep Wrangler Unlimited Rubicon
Livingston, TX  SKP's Fulltiming

Re: How to repair your Dometic 4 button thermostat

Reply #8
Why thanks, Dave, appreciate the bump.  Glad it was useful for you. 

Chuck
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: How to repair your Dometic 4 button thermostat

Reply #9
I ordered 10 switches from Mouser (switches cost as much as shipping). I finally got around to taking the contacts out of 2 new switches and putting in the 4 old ones. I just replaced the one side that is connected to circuit....works like new. THANKS!

A paperclip works great as a little tool to slide under and hook the metal contacts and put them in place. Whole job took about 15-30 minutes with learning curve. If I had to do it again, 5 minutes.
1998 U270 34'

Re: How to repair your Dometic 4 button thermostat

Reply #10
Hadn't seen this thread before.  Good future reference.  ^.^d

Larry
Larry Warren
1996  U320 36' SBID "Lola"
Build #4970
Motorcade #18318

Re: How to repair your Dometic 4 button thermostat

Reply #11
I had not seen it either, and am very glad to see it now.  I'll get after this little task and make the DW happy with the thermostat again.  Thanks Chuck.
Bob Thomas
Sacramento, CA
Present:  1997 U320 '40
Previous: 1997 U295 '36
Bluegrass fan, and festival emcee

Re: How to repair your Dometic 4 button thermostat

Reply #12
I took them apart and cleaned them with spray electrical contact cleaner from radio shack.  It's been about a year and they are only starting to get funky again.  I'll probably do it your way now.

Re: How to repair your Dometic 4 button thermostat

Reply #13
I called Mouser for number  PVA10AH2 and talked with a great tech and after he researched that part number and found they had gone obsolete. The tech referred me to onlinecomponents.com. The switches I ordered which are a little longer but so cheap I could not resist and if the buttons are too long I'll Dremel them down to the proper size or screw them up completely.  The number I ordered is PVA10AH21.2NV2 They are solder in but I don't see a problem with that.
There is a guy that rebuilds the thermostat for $150 I have talked with him several times he's a very nice guy. You have to send him your thermostat he has no cores without your old one.
His contact info is: Jim Frerichs, 4102 Lark DR., Mission,TX-- Phone is 308-440-5154 (4 button Dometic Thermostat Repair)
Hope that helps

Re: How to repair your Dometic 4 button thermostat

Reply #14

There is a guy that rebuilds the thermostat for $150 I have talked with him several times he's a very nice guy. You have to send him your thermostat he has no cores without your old one.
His contact info is: Jim Frerichs, 4102 Lark DR., Mission,TX-- Phone is 308-440-5154 (4 button Dometic Thermostat Repair)
Hope that helps

Jim is a long-time Foreforums member

Dometic 4 button thermostat repair
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

Lifetime Escapees' member SKP 82766
Former 1999 30IB Lazy Daze (2000-2004)
Former 2003 U320 (2004-2016)
Former 2017 LTV Unity (2017-2023)
Shopping for our next coach

Re: How to repair your Dometic 4 button thermostat

Reply #15
Same member who rebuilds the Aqua Hot controllers. The one he did for me is still going strong.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: How to repair your Dometic 4 button thermostat

Reply #16
Another sometime problem with these thermostats is the on/off switch.  My a/c would sometimes just shut off for few minutes and then turn back on.  Turned out the soldier connections for the switch crack.  A soldiering iron and a little fresh soldier will fix the issue. 
1998 U320 40'
2005 GMC Yukon
MC# 17609

Re: How to repair your Dometic 4 button thermostat

Reply #17
It's been a while, and once again my thermostat started acting up again about five years after replacing the contacts.  Being in a bit of a rush I just removed the cover, didn't disassemble the switches, gave em all a short shot of Deoxit and they've been working flawlessly for three years now.  Deoxit is miracle stuff in a can for electronic/electric devices.
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: How to repair your Dometic 4 button thermostat

Reply #18
I replaced the contacts and springs in mine last spring. One of the best hacks I've done. It really improved my inside coach vocabulary.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: How to repair your Dometic 4 button thermostat

Reply #19
Replacing the springs and contacts may be the easiest coach repair possible and lowest cost, outcome works well, having completed my repair about two years back. Found the HOW TO on this forum. Great group of folks, thanks for sharing !
Charles
W5CRY
1997 Dynasty - Sold

Re: How to repair your Dometic 4 button thermostat

Reply #20
X3 on the contact replace/repair. I changed mine last year, works perfect.

Larry
Larry Warren
1996  U320 36' SBID "Lola"
Build #4970
Motorcade #18318