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
Chuck,, it shows 23mm on the website under that part # and they are soldered???
John H
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.
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
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.
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.
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
Why thanks, Dave, appreciate the bump. Glad it was useful for you.
Chuck
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.
Hadn't seen this thread before. Good future reference. ^.^d
Larry
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.
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.
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
Jim is a long-time Foreforums member
Dometic 4 button thermostat repair (https://www.foreforums.com/index.php?topic=21786.0)
Same member who rebuilds the Aqua Hot controllers. The one he did for me is still going strong.
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.
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.
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.
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 !
X3 on the contact replace/repair. I changed mine last year, works perfect.
Larry