Furnace - Montana Owners Club

furface · 10-20-2014, 03:59 AM

I have a new to me 2008 Montana 3465SA. And this last weekend we were camping and it got down to the low 30's. Our furnace was coming on about every 10 minuts is this how the new furnaces work ??. If not what should I look at.
Thank You

1retired06 · 10-20-2014, 04:05 AM

They run via thermostat, so when you hit the temperature you set it at, the furnace shuts off and then comes back on when the temperature drops.

jimcol · 10-20-2014, 05:19 AM

1retired06 describes the functionality to a tee. The reason the furnace cycles so often is these units are not air tight sealed especially around the slides, and the walls are not well insulated because they are not very thick. Temp's transfer pretty easy in these units. Based on your description your furnace is functioning just like mine and all other Montana's that I'm familar with. When it is cold you can keep them warm but it requires a lot of propane. We use an electric heater or the fire place to reduce propane use and the annoyance of furnace cycle. Jim

kdeiss · 10-20-2014, 05:29 AM

By reading your thermostat instructions you can adjust your thermostat temp differential from 1 to 2 degrees.

TAKPAK · 10-20-2014, 06:24 AM

Furface, 10 minutes isn't bad, especially at those low temps. The furnace is functioning normally. I also note that you have a 2008. While I am not necessarily promoting the newer models, there is a difference. We had a 2008 model (3400) and the furnace ran a lot. It was cool and a bit drafty. Then we got a 2011 3400. Better, but not great. We now have a 2014 3725, and the difference is quite noticeable.

Warmer, no drafts, furnace runs a lot less, etc.

As with others, we use the electric heaters/fireplace when at a campground that electricity is provided.

**DQDick** · 10-20-2014, 06:25 AM

If it's not a thermostat issue check to see if some insect hasn't built a nest that partially obstructs the exhaust vent on the furnace. The furnace could be going out on a high temperature shut off.

Overlord · 10-20-2014, 10:21 AM

Another reason that it can be cycling on and off is the cut-out in the wall behind the thermostat is way, way bigger than it needs to be and allows cold air in the wall panel to affect the thermostat. I removed it from the wall and patched the hole with foam and duct tape. The thermostat wires now come through a tiny hole in the tape, not a huge gaping hole in the wall.

...and, these rigs are just not very efficient at holding in the heat when it is very cold outside. When we stay at an RV park, we use a couple of electric ceramic heaters to keep tolerably warm at night. I can't sleep very well when the furnace kicks on and off all night long. When we boondock (as we do most of the time) the furnace fan sucks the batteries down too quickly, so we use a catalytic propane heater during the day, and at night we generally leave the furnace off and use goose down comforters to sleep under, unless it is freezing temps outside, then we set the furnace at around 60F to keep the pipes and tanks from freezing up.

PatM · 10-20-2014, 01:25 PM

I have a 2013RE. We are satisfied with the heat distribution throughout the unit but hate the noise from the heat vent in the bathroom. It sounds like a "wind tunnel". We close the inside door during the evening.

DonandBonnie · 10-21-2014, 03:28 AM

Your furnace provides heat to your holding tanks and the basement. If you use auxiliary heat sources, be careful that you don't eliminate some cycling of your furnace during sub freezing temperatures.

kingrving · 10-21-2014, 03:29 PM

I've got a 2004 2980RL and the best thing I ever did was to replace the orginal thermostat with a digital. The temp in the coach stays very consistent without the on/off cycling. Not sure if this helps you but for under $30 you can upgrade and there are plenty of instrutions online to walk you thru the process.

furface · 10-22-2014, 04:17 AM

Thanks for tih information on the furnace. Also would it help if I plastic bucket over the attic vents in cold weather ??
Thanks

**DQDick** · 10-22-2014, 04:55 AM

I would say no. We never did it and some of those vents are used to vent the attic between the roof and the coach. Covering them would be like covering roof vents on a house (which I know some people do), but that traps moisture in there, wets the insulation reducing the R value and can lead to mold up there that you don't want.

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