I think I posted this issue around last May. I just tried to search for the post, to update it, but couldn't find it.
Is there a way to review my past posts?
More importantly.....My Comfort Control doesn't light up when I move the switch to "on". This has happened a few times, now. I think I asked where the t-stat got its power from, but, again, didn't find that topic. I disconnected the phone looking connections in both front and back a/c units, sprayed them with contact cleaner, and worked them in and out. This SEEMED to help the last few times, but not today.
We are packing the coach up for our yearly trip to Mexico, so heating and cooling that works would be a real nice thing to have working properly.
Any suggestions of how to track down the problem?
Thanks
This one? Comfort Control kaput (http://www.foreforums.com/index.php?topic=41950)
Have you tried a different T-Stat? I have a known working one I can loan you.
Otherwise a few of us have converted over to this plug & play upgrade: EasyTouch RV™ Thermostat – Micro-Air, Inc. (https://www.microair.net/products/easytouch-rv-thermostat)
Elliot,
Does the replacement t-stat use the same phone jack that goes into the back of the Comfort Control.
I'm only here, in Maine, until the 14th, then on the road. I could have you send it to my brother-in-law in Texas. I think I'll look into buying the new upgrade, if you think that could fix the problem. Is there a test to see if I'm getting current to the t-stat?
And thanks for finding my previous post!! Nice work
Yes
12 power comes from a breaker that is in compartment behind white cover. At one time I had to disconnect the wire so I could reset the system.
I just Googled the replacement. Which model? They seem a little costly...????!!!!!$250??
Yup, it's a direct fit for the 5-button comfort control. It is NOT plug and play with the 4-button unit though, there's more work involved in that scenario.
WiFi/Bluetooth thermostat upgrade from Dometic 5-button (https://www.foreforums.com/index.php?topic=43096.msg433501#msg433501)
You're paying for the ability to control it from your phone. It's pretty slick when you're laying in bed and want to turn the heat on at night ^.^d
The model I have is: EasyTouch RV 357
You can also set it with a high and low temps. Temp get too high, AC turns off. temp get to low, heat come on.
Only want the heat to come on say 7AM?, just set a schedule for the heat to turn on at 7AM and pick the temp you want it to go up to.
If you have it connected to an internet connection you can check or change the temps from anywhere.
I have the four button T-stat so yours may be different problem
The solder joint connecting the on/off switch to the board had cracked on mine. I had intermittent problems and finally it totally quit.
Try wiggling the switch to see if it tries to come on. If yes, it may be solder joint.
12 power comes from a breaker that is in compartment behind white cover. At one time I had to disconnect the wire so I could reset the system.
Sorry.....compartment behind WHAT white cover?? The T-stat? How did you reset the system?
I have the same unit that Elliott mentioned, #357. If you have the 5-button Dometic controller now, it's a direct, plug-and-play replacement. If it's the controller that's the problem, this should resolve that issue, plus give you a lot of nice added features like scheduling and remote access like Turbojack mentioned.
Sounds great.
I just would like to be certain:
A) I have power to the existing t-stat. I will TRY and check the red/black wires tomorrow
B) It isn't simply the 3 v fuses. I had the units running about a month ago, so I think its NOT that.
I will order one tomorrow.
This is what is in mine Amazon.com: Dometic 3314082011 Appliance Components Rv : Automotive (https://smile.amazon.com/Dometic-Digital-Comfort-Control-Center/dp/B00CXB8BY6) Works fine for the dual ACs. I don't have AH though, just a meager 295.
Same one that came in my coach when we bought it. Has AH setting too.
In one of your lower compartments (drivers side?) there is a white cover that is held on with thumb screws, that is over all of the circuit breakers. I had to find the correct one and remove the nut to get the wire off to kill the power to the thermostats and system.
Yesterday, the t-stat would not light up, when I moved the switch from off to on.
As I mentioned, this has occurred a few times, since last May.
I left the unit " on ", overnight. This morning, as I walked by the coach, I heard the sound of the a/c running. Went inside.....yup....
t-stat was lit up and a/c on. Soooooo.......any ideas???
I HATE intermittent problems, like this!!!!
Intermittent means it will work when it doesn't matter and not work when it is critical. Almost always.
Check all all of the phone cable connections. From the rear AC to then front AC and at the back of the thermostat. Lots of couplers and connections. 12v to the thermostat comes from the ACs. If the thermostat works some times and seems dead others power is where I would start. It could be a cable, a connector, a circuit board or maybe the thermostat. A new 10 button thermostat replacing a 5 button thermostat may not be a direct plug and play. Some have gad to change boards in the ACs but thos might have been 4 to 10 swaps.
Glenn, it sounds like you need to replace the thermostat. Boards to go out or have loose connections over time. Good luck with your issue!
The AC is getting the 12V from the coach's 12V system. If you were to loose your 12V power from the coach's 12v system, and still had 110v to the AC the AC would not work. They need the 12V from the coach to be able to work.
As I mentioned above, this has been an intermittent problem....the WORST kind of problem.
I did order the VERY EXPENSIVE T-stat, as recommended.
I did NOT install it, as my original t-stat decided to light up and operate.......
Until today.
This problem seems to occur after the t-stat hasn't been used for a while, as in when it is in storage, or recently, not used for either the A/C nor heat. I don't know if that has any relevance.
So......I decided to install the plug and play Micro Air
No instructions came with this thing.
I plugged....
NO PLAY
It doesn't light up !!!!!!??????
What is my next step? I wanted to test to see if the phone jack was getting power, but I only have standard tester.
Any help would be greatly appreciated
If I recall correctly, it's require no set up to use at the screen. You should be able to plug that telephone cable in and start controlling things immediately. It makes me suspect your power source or a ground going to it. A loose ground may explain the symptoms you were seeing with the old T stat.
Any ideas as to how to trace it?
This isn't my strong suit
I agree with Elliot, it should be "plug and play". If you you want remote controlling, that's another story, ie, Bluetooth, Wi-Fi.
I'd start by inspecting the plug and cleaning it up. Low hanging fruit. After that I suppose it's time pop that wood panel/run off the wall and see what's back there. Maybe a mouse chewed something up. I have no idea where it runs... that might be a Rudy question.
I'd probably let this thread percolate for half a day before I started tearing things up. Someone may be able to chime in and suggest some low hanging fruit to inspect
Will do
I can wait
It is like a 6 wire phone cable. Rear goes to the front. Then there is a coupler nd then it goes straight to the front end, left to the driver's side overhead cabinets then through the cabinet floor and down the column where the thermostat is. Any of the connections or plug in connectors might be suspect. Both AC units have a 12v wire and a ground. Power to the thermostat likely comes from the front AC.
"Like a six wire phone line" but maybe not exactly. Usually these data cables have the ends reversed from one end to the other. One side of the flat cable usually has a ridge and the other side is smooth.
Glenn,
If both the new and old thermostats occasionally come on with attempted use and then go blank, I would suspect the phone cable or the phone plugs are the problem because the 5 button thermostat and the micro-air usually are very reliable. Both of them use digital communication so the analog style thermostat will not work.
After you have checked for bad fuses, the red and black wires in the plugs supply the 12 VDC. Green and yellow for data.
Check to see if the plugs are clean and fully seated in their phone jacks at both the thermostat and at the air conditioners. Also, water leakage causing corrosion, mice eating the cable or vibration are common causes of this type of failure. I also have seen bad inline couplers (sometimes used to convert cable types) on these lines near the air conditioner jacks.
As an easy test for bad cables is to buy another data cable. Or with the proper crimping tool and plugs, convert a phone cable to a data cable. String it through the air to make the substitute connections. At Walmart these data cables are "straight "phone cables and Amazon calls them "reverse" phone cables. Home Depot and Lowes may have data cables too.
Just like looking for your car keys, you will find the problem in the last place you look.
Jim
The original t-stat did not light up when I turned on the switch
The new unit did not light up when I plugged it in
It came with no instructions
I imagine that, if there was 12 v power, then BOTH would light up
I would have to strip the wire near the t-stat to get a probe on the black and red lines
Unless there is a better way
Glenn, go to their website and download their installation/operation manual for the easy touch!
Has anyone verified that the thermostat gets 12 volts directly and not through the phone cable? When I switched out my 13.5K for a 15k I thought the 12 volts were sent through the phone cable. If so you need to go to the source which is the circuit board on under the cover on the roof unit which might explain weather issue. There is also a red and black 12 volt supply under the air register cover that you could verify voltage.
Do not strip the wires or cut off the plug to read the voltage. Big mistake.
Use small, straightened paper clips or straight pins held to the meter probes to read the DC voltage on the plug's contacts.
If you found 12 volts on the plug then with it plugged in, try looking for 12 volts on the back of the thermostat - with the switch In the on position.
Jim
I have not tested the 12 volt yet. How do I determine which wire is black and red without striping the main wire?
ALSO....
I left the switch to my original t-stat "on" for about two days. Then, it MAGICALLY fired up my a/c unit, one night. The next day, I plugged in the new, high dollar t-stat that I was told to get.
It lit right up, also. I need to read the manual, to understand how to use it, but for now I am still using the old one.
Let me know if anyone wants the new one, when I get back to the States, as this clearly is NOT the problem.
The only wiring connection to the thermostat is the phone-like flat cable.
If you are having intermittent power issues pull down the inside AC covers and verify the 12v plus connection and the ground connection.
IHi Glenn,
I would be interested in your old thermostat. 3 zero 8 4 four zero 5 one 5 four JIm
If you are having intermittent power issues pull down the inside AC covers and verify the 12v plus connection and the ground connection.
[/quote]
OK
Where do I look for it?
How do I recognize the connection?
Not the phone cable, but a separate wire?
There 12v +wire will most likely be white and the ground wire, green. Grounds are connected to the frame opening towards the front near the 120v box. 12v + wire probably comes out just to the right of the box.
Pull down the screen/filter cover from the inside cover. AA I recall there are four screws to remove to drop the inside cover.
Once again, thanks, Roger!
Glenn.
In the phone type plug for the Dometic 4 and 5 button thermostats, use opened safety pins held against the voltmeter probes to be able to reach the contacts between plastic dividers of the plug. Normally the red is positive and black is negative for 12 VDC, but who knows how different manufactures have wired it. The green- and yellow-colored wires normally observed in the plug are for data transfer to and from the A/C circuit boards. They may show some much lower DC voltages as well - unrelated to the power source. you are looking for. You may need to cross-check all color combinations.
If no 12VDC voltage is found, check the fuse on the A/C circuit boards or suspect bad plugs, jacks and phone cable.
Jim
Frerichs Electronics
2002 U320 42'
Thanks
Will do
Update:
As I had previously noted, this is an intermediate problem. When I did have power to the Comfort Control, I plugged in the Micro- Air Model 357 that was recommended to me. It, also, lit up. I reinstalled the original t-stat.
Yesterday, when I tried to fire up our air conditioner, there was no power. I had our Mobil RV repairman in my coach, working on my Microphor problem. We believe that the problem is with the control circuit board on the front unit. When I did have power to the t-stat, everything worked fine. He informed me that these boards are hard to find. In a past post, about replacing air conditioners three years ago, David S told me he got one on E-bay. I will be going up on the roof to find the model number of the board and try to find one, when we get back to the states. Can my existing board be repaired??
ALSO....I may want to sell the Micro- Air, since I don't believe it is the T-stat. Anyone wanna buy it from me, unused, new ????
When I get back to the states in May.
Getting warm here.
PIcture....
I was coveting that thermostat before I bought the Furrion system.
Why isn't all of this stuff Bluetooth by now?
So I have a similar issues with my AC. I can turn on my 3 button thermostat and it lights up. BUT the view on the thermostat only shows zone 1. When I go to AC nothing happens. In investigation I disconnected the phone cable from the fron to rear AC and the front AC worked. Nothing of course from the rear. The 4 button duo therm of course still shows only zone 1. No zone 2. ALSO the front AC works but is continuous and the fan runs constantly. I did buy the duotherm 5 button thermostat and 2 control boards but have yet to install. Is there something simple that may be the cause before I go ahead and try the upgrade. Saw lots of talk about a fuse in the control board and phone wire going bad. Maybe the cause.
Help and knowledge would be appreciated!!
Hi Peter,
Your email mentioned 3 button and 4 button thermostats.
When the 4 button thermostat push buttons begin to fail, it temporarily scrambles the chip in the thermostat. Replacing the push buttons usually brings it back to normal, though occasionally resetting of the thermostat is needed afterwards.
Five button thermostats will not work with a 4 button A/C system. Hope you can return it or consider upgrading to a five button system - lots of work and greater expense.
Get hold of me for more help,
Jim Frerichs
308-440-5154
Sorry finger issues. 4 button and 5 button
I think that he said he had a 5 button tstat and new 5 button upper boards. Sometimes you can spray electrical contact cleaner on the cable ends and the couplers. The Dometic couplers are not the same as telephone couplers.
I just got done spraying contact cleaner and gently swabbing with Q Tip.
STILL no power to t stat. Went up on roof and opened front a/c unit. 3 amp fuse good. NO apparent corrosion or loose wires. will go check behind white panel tomorrow. Then....????????
Is there 12 volts at the 3 amp fuse? Thanks
Glenn,
If there is no 12 volts at the air conditioner fuse (to ground) then you might look for a fuse in the coach fuse panel (under the refrigerator?) or a tripped circuit breaker behind the white panel. If you are lucky your white book schematics might show 12-volt power for the air conditioner circuit boards. Also, you might check for a broken data cable, plug, jack, etc. either for positive or ground.
Jim
2002 U320 42'
My MO , when the t stat doesn't light up, is to leave the power switch "on". On two different occasions, I have come back, the next day, and there is power on the unit.
Yesterday, after three days of no power to the t stat, I went to bed with switch in the "on" position. I woke up, around 1:00am, to the sound of BOTH of my a/c's running, and the t stat lit up.
Instead of simply turning off the power switch, as I usually do, I turned off each a/c unit in the mode setting. The t stat is still "on".
Soooooo.......Can I leave the t stat in this position, without causing damage to it?
ANYONE have any ideas as to what is going on with my power to the t stat. This is making me crazy. I will leave it on, as it is getting warmer here, in Mazatlan, unless I am doing something wrong.
Thanks.
Symptom screams bad connection somewhere. Not sure of how to help you find it. My thermostat is always on and has been since we have owned the coach.
Glen,
1. Yes
2. You need to check the on/off switch (on the thermostat) to see if the contacts are bad, if so replace (or have someone replace) the switch.
Mike
2. You need to check the on/off switch (on the thermostat) to see if the contacts are bad, if so replace (or have someone replace) the switch
[/quote]
Problem is that when I plugged in the high dollarIT stat, it wouldn't light up, either. Now that the t stat is "hot " the new one works also.
That would preclude a switch problem, wouldn't it??
Glen,
If that is the case then I would be looking for a bad end on the cable that plugs into the tstat. and goes to the AC units. The ends are thriftly made but are simple to change out. New ends can be found at most any home improvement store (along with the crimping tool)
Mike
Glen,
The power (12vdc) that feeds the thermostat comes from a breaker that is located in the set of breakers that are hid behind the removable kick panel in front of the passengers seat. On your coach year seems like it is in the range of breaker #50 to 54 find the correct breaker for future troubleshooting. That is a self resetting breaker and it could be failing. IIRC that is a 5 amp breaker. Next time you loose power see if you have voltage on both sides of the breaker. That breaker also has a second item feeding off of it but I don't recall what that is at the moment.
Mike