Community Forums

DaveFrench7 · 07-01-2022, 11:05 AM

I replaced a Duo-Therm Comfort control which controlled the AC, heat pump and Hurricane furnace with a Dometic Comfort Control Center (model 3314080.015). Everything seems to work except the hot air fans from the furnace.

There is a control panel separate from the thermostat which has on/off switches for the furnace and the furnace fans levels. It also has an LED light which tells if the furnace is working correctly (green).

I configured the new thermostat furnace control to "AQUA" to see if the furnace worked. When nothing happened, I switched the on the on/off switch on the separate control panel; the LED was green and the furnace fired up. At his point I switched the fans on and neither of the galley fans or the galley fans worked. I checked the master circuit board on the furnace and there were no faults.

Any ideas? I looked for an installation manual for the new thermostat to no avail. It was installed by a Coach shop along with 2 the AC units.

DJ55 · 07-01-2022, 06:24 PM

There is a manual for your thermostat at https://www.dometic.com/assets/47/55...nual_64755.pdf, maybe it will help with your installation and programming questions.

birdhunter · 07-01-2022, 10:28 PM

I don't think the CCC turns on the fans. It would turn on the Hurricane via the control board in whatever zone air conditioner is involved. The fans would be controlled by the Hurricane board and those Hurricane controls upstairs.. At least that's how I think it works.

phays · 07-02-2022, 04:42 PM

The fans for the hurricane heat exchangers are controlled by the 4 or 5 button thermostat. Any time the furnace is running the heated fluid is pumped through the heat exchangers. This is also true any time the engine is running. Should the thermostat sense the temperature in a zone is too low that zone heat exchanger fans are turned on. When the temperature is satisfied the t-stat turns the fans off.

Contact Dometic and see if the new t-stat will work with your existing heat pump/AC's.

**CountryFit** · 07-02-2022, 06:09 PM

Quote:

Originally Posted by phays

The fans for the hurricane heat exchangers are controlled by the 4 or 5 button thermostat. Any time the furnace is running the heated fluid is pumped through the heat exchangers. This is also true any time the engine is running. Should the thermostat sense the temperature in a zone is too low that zone heat exchanger fans are turned on. When the temperature is satisfied the t-stat turns the fans off.

Contact Dometic and see if the new t-stat will work with your existing heat pump/AC's.

This is how my hurricane/heat exchanger fans are working.

OP - what year and model of your coach is, and what new t-stat did you put on?

birdhunter · 07-02-2022, 10:56 PM

Quote:

Originally Posted by phays

The fans for the hurricane heat exchangers are controlled by the 4 or 5 button thermostat. Any time the furnace is running the heated fluid is pumped through the heat exchangers. This is also true any time the engine is running. Should the thermostat sense the temperature in a zone is too low that zone heat exchanger fans are turned on. When the temperature is satisfied the t-stat turns the fans off.

Contact Dometic and see if the new t-stat will work with your existing heat pump/AC's.

The thermostat has to also turn on the Hurricane burner or the fans will provide no heat, unless you're driving, in which case hot engine coolant is always circulating through the heat exchangers.

phays · 07-03-2022, 04:56 AM

I will add that the Duotherm t-stat turns the furnace on. The burner is controlled by a t-stat in the furnace that controls the temperature of the circulating fluid.

birdhunter · 07-03-2022, 10:21 PM

I am currently dealing with a situation where the five button CCC clearly shows the furnace in zone 2 on but no burner, no fans for that zone. I am trying to determine what the problem is. I think it must either be the CCC or the board in the zone 2 Duotherm air conditioner but I have not yet determined which it is. Zone 1 works perfectly.

**CountryFit** · 07-04-2022, 11:14 AM

I read it before that 4 button to 5 button conversion isn't a plug n play; a significant work has to be done on the control board on the a/c units. No first hand experience though.

gnvrvin · 07-05-2022, 08:03 AM

Quote:

Originally Posted by birdhunter

I am currently dealing with a situation where the five button CCC clearly shows the furnace in zone 2 on but no burner, no fans for that zone. I am trying to determine what the problem is. I think it must either be the CCC or the board in the zone 2 Duotherm air conditioner but I have not yet determined which it is. Zone 1 works perfectly.

Rich is there way to place zone 2 on zone 1 wires to see if it works
That should show if it's the ac board

Greg

birdhunter · 07-05-2022, 10:21 PM

Quote:

Originally Posted by gnvrvin

Rich is there way to place zone 2 on zone 1 wires to see if it works
That should show if it's the ac board

Greg

Excellent idea Greg. I'll have to study the wiring diagrams and see if there is a way. For now, I have moved the fan wire for zone 2 over to zone 1 so at least I have heat in the bedroom. Of course it's all controlled by the zone 1 thermostat in the living room which is not ideal.