Bad Thermostat or something else?

[Nonno]

I have the Duo-Therm Comfort Control Center (2 zones), part # 3109228.001. Modes of operation are OFF, FAN ONLY, COOL, HEAT PUMP, FURNACE.

Worked fine night before last on HEAT PUMP and yesterday on COOL.

Today is a different story. I was trying to use FAN ONLY mode but it would not come on. Pressed "zone" to see the mode but only thing that appeared on display was "zone 1 2" at the bottom. Normal description of which mode it was in did not appear. Turned it off then on again. Everything appeared the way it should so I set it for FAN ONLY. After about 30 seconds still no fan turning on and backlight and description go off. Press "zone" again and only thing that appears is "zone 1 2" at the bottom. Turning it off and then on again the mode description reappears but it does the same thing as before. Other thing I noticed after turning it off, then on again is that the only mode options are OFF, FAN ONLY, and COOL. HEAT PUMP AND FURNACE don't appear anymore. Fortunately weather today and tonight will be ok so I don't need AC or Heat.

Haven't found any blown fuses or tripped breakers. Everything else 110vac and 12vdc are working fine.

What do you think, bad thermostat or something else?

[Norm4015]

Try doing a reset. I think the procedure is to turn it off and while holding down the top and bottom buttons turn it back on, then release the two buttons. It will read the settings on the circuit board and will re-program itself.

[Nonno]

Tried it. Holding both buttons down initially it shows "FF" when turned on then goes to "EE" when buttons released. "EE" and backlight stays on compared to display normally shutting off after a short period.

If it's reprograming, (1) is this what it's supposed to do? (2) how long does it take?

Finally turned it off and back on again. "EE" still there. If I hold buttons again when turning on, it goes thru the "FF" and "EE" cycle again.

[RVhauler]

From previous experience suspect bad control board

[Norm4015]

Quote:

Originally Posted by Nonno Tried it. Holding both buttons down initially it shows "FF" when turned on then goes to "EE" when buttons released. "EE" and backlight stays on compared to display normally shutting off after a short period. If it's reprograming, (1) is this what it's supposed to do? (2) how long does it take? Finally turned it off and back on again. "EE" still there. If I hold buttons again when turning on, it goes thru the "FF" and "EE" cycle again.

The reset or reprogram only takes a second. After getting the FF and releasing the top and bottom buttoms, the display should show the zones in the bottom of the display. At that time you press the mode buttom to select the mode for each zone.

I assume your EE indicates an Error or problem. I hope someone with more knowledge than me can help.

[Nonno]

Good news is that this problem occurred while camping close to home rather than on my trip to MB in 10 days. I have an appointment with local dealer on the 29th.

Unless there is some override that lets you turn on heat or ac, makes me wonder if I should carry a spare thermostat. I was fortunate that the weather didn't require either heat or ac.

Thanks for your help.

[Nonno]

Found the problem and fixed it! Cost me $44 for splicer and 4 pin connectors from Radio Shack

Spoke with Monaco Tech Support who informed me the "EE" code was a communication error and told me how I could troubleshoot it to determine if it was the wire connecting the thermostat to the AC.

FYI - Here's the procedure I used but first let me explain the connections between the thermostat and the 2 zones.

Thermostat has one wire (it's a 4 pin connector similar to your telephone) that connects it to Zone 1. Zone 1 has that wire plus a second connecting it to Zone 2. There are other wires such as power and remote sensors but those are not involved in troubleshooting my "EE" issue.

Remove the thermostat from the wall and unplug it. Now remove the filter/ screen from Zone 2 AC and unplug the wire coming from Zone 1. Plug that into the thermostat. If the thermostat functions properly (you'll only see zone 1 because you just disconnected zone 2) the problem is the wire between the thermostat and Zone 1. In my case it was.

Knowing which wire is the problem still leaves you with finding the trouble spot and/or snaking a new wire. I was fortunate to find the problem was a break within a foot of the connector at the Zone 1 end.
Cut, crimped, tested and IT WORKED!!!

[Norm4015]

Doesn't that make you feel good.

Now you know more about your climate control system than anyone on iRV2.

[Nonno]

Feels real good. Thank you for your help.