I was having problems with the heat in my RV and rather than get a brand new 5 button Duo Therm with the attendant retrofit problems I purchased what I THOUGHT was a remanufactured one for $149 on eBay.
Much to my surprise, about ten minutes after I paid through PayPal I got a phone call and voice message from Nebraska! Calling back I spoke to Jim, who informed me that he did repairs on Duo Therm and I would need to send him my old one. He then asked me what my problem was. After describing it to him, he told me that he doubted that I would need his services and told me how to set the two zones so one would not conflict with the other. I tried it and it worked! I was so pleased I told him to keep $30 for his services. He promptly refunded my money and, as well, sent me a factory reset procedure to use if all else fails, that I'm including here.
If you have problems with Duo Therm please give Jim a try. He's a great guy and more than fair!
http://www.frerichselectronics .com
Subject: reset procedure for Dometic 4 button thermostat
If zones or other functions do not work - do this Reset Procedure for your 4 button Dometic thermostat.
1 Connect the phone type cable to the back of the thermostat and turn on the power switch.
2 If possible, on any zone set the heat and cool (each) to 70 degrees on the display.
3 Momentarily depress and release the mode switch - the display lighting should come on.
4 Depress and together hold down the two bottom buttons (up and down).
5 While still holding the two bottom buttons add the third button from the bottom (mode button).
6 Release the third button (mode) first.
7 Then release the two bottom buttons (up and down) together.
8 Momentarily depress the mode button. The display light should go off. If not, repeat steps 1-8.
This reset procedure programs your thermostat to your RV's systems and temporarily defaults to settings of 68F for the heating and 72F for the cooling. Look for these temperatures as proof
Linear Mode
