Community Forums

aerostar · 03-06-2010, 10:13 PM

I have a motorhome with two zones. The front and much larger zone has a furnace for heat and a Dometic Brisk Air A/C for cooling. The rear and smaller zone heats and cools with a Brisk Air Heat Pump. They are both contolled by a Dometic "Comfort Control Center" (five button).

For the longest time I have been plagued with inconsistent operation of the rear Heat Pump when in heat mode. Sometimes it worked, most of the time it didn't. Well I finally figured out why - the thermostat is designed to not allow furnace mode and heat pump mode at the same time - even on different zones!

Seems like a stupid way to set up a motorhome, but as the manufacturer is gone (Safari) I have no one to complain to.

Does anyone have any ideas for how to allow my front zone to be heated by a furnace at the same time as the back zone is heated by the heat pump?

Thanks for any ideas!

Mandys Man · 03-06-2010, 10:41 PM

Quote:

Originally Posted by aerostar

I have a motorhome with two zones. The front and much larger zone has a furnace for heat and a Dometic Brisk Air A/C for cooling. The rear and smaller zone heats and cools with a Brisk Air Heat Pump. They are both contolled by a Dometic "Comfort Control Center" (five button).

For the longest time I have been plagued with inconsistent operation of the rear Heat Pump when in heat mode. Sometimes it worked, most of the time it didn't. Well I finally figured out why - the thermostat is designed to not allow furnace mode and heat pump mode at the same time - even on different zones!

Seems like a stupid way to set up a motorhome, but as the manufacturer is gone (Safari) I have no one to complain to.

Does anyone have any ideas for how to allow my front zone to be heated by a furnace at the same time as the back zone is heated by the heat pump?

Thanks for any ideas!

Are you sure the front one is not also a Heat Pump?? With the 5 button CCC, they should be. Maybe the reversing valve is stuck.?? Monaco is alive still in Oregon and tech support should be able to help, although complaining will get you nowhere. I'd call and ask them some questions , maybe they can come up with some answers.
Also ask for the Build/data sheet for your coach. Maybe it (the HP)was replaced with the wrong type sometime in its life. You will need the coach # (last 6 of the serial) when you call

Route 66 · 03-07-2010, 05:27 AM

I don't think you can have the heat pump and furnace running at the same time.

I believe it's one or the other.

aerostar · 03-07-2010, 05:47 AM

It's definately not a heat pump in the front. I checked the model numbers with dometic. (they are different) I'm pretty sure it's by design and not a mistake since the front zone is 30' of the motorhome and I don't think a heat pump would adequately heat it. The rear zone is only 10' and is a toy garage, which is why the furnace is not ducted to it. (fumes)

I will try Monaco as you suggest. Thanks.

Jim Stewart · 03-07-2010, 06:36 AM

If the front is an AC unit only and not a heat pump and it is working the way you say, the units are probably set up the wrong way (Dip-Switches). It sounds like it is set up for dual heat pumps. In that scenario, the furnaces will not work in the heat pump mode and it is programmed to turn the furnaces on when the temp is below a certain level and the heat pumps won't work or they are in a defrost mode. PM me with your e-mail address and I will send you the troubleshooting manual for the Comfort Center.

sundancekid · 03-07-2010, 06:57 AM

If you buy a second thermostat, like from ebay, it's pretty simple to disconnect the "phone cord" between the two units and control them both as separate systems with separate thermostats. You will have to change the "dip switches" in the rear unit to be a master. I did this in our MH because I was tired of going up front to change the temperature in the bedroom.

aerostar · 03-07-2010, 11:27 AM

Jim-

I was thinking the same thing, but I checked all the dip-switches on both units and even reset the control center trying to make it work. It wasn't until almost midnight that I found the following tidbit in the comfort control center operating manual -

"Please note: The Comfort Control Center will prevent operating

FURNACE and COOL or FURNACE and HEAT PUMP at the same time."
This makes some sense in situations where the furnace is ducted to the entire motorhome but there are several zones for cooling/heat pump, but for my particular setup doesn't make any sense at all. I was kind of hoping there was some super secret dip-switch setting that might make this go away, but I'm not holding my breath.

Sundance-

I think you may be right, I was hoping for something quicker and I will check with Monaco and Dometic before I do it, but a second thermostat seems to be the solution.

Thanks for the ideas - keep them coming.

Gary RVRoamer · 03-07-2010, 02:17 PM

I can't find that "Note" about Furnace and Cool/Heat in my Atwood Comfort Control System documentation, but I can't find a couple things I know it does. For example, mine will start the gas furnace if the Heat Pump is on and the temperature differential is 5 degrees or more. The heat pump continues to run.

My coach isn't here right now, so I can't test it. Will have to see if I can have one zone in Heat while the other is IN Heat Pump or Cool. I've never tried that, except perhaps for a few seconds while switching modes.

There are some variations in how the ACCS t-stat works depending on the type of equipment installed. I have RVP heat pumps and the Atwood two-stage Excalibur furnace and that gives some capabilities that some other configurations do not have. I'm sure there are other variations as well.