Furnace question

[Cjhernandez]

Just went out on our 2013 3170DS and it was a bit cold. First time we use the furnace. We turn the furnace on and both the furnace and the air unit come on. The furnace blows hot air but cool outside air seem to be coming through the air vents. I thought that while on "furnace" only the hot air should work not the roof air unit? Help we are cold!

[crunchman12001]

Hi,
Very common issue.
Turn the fan to AU.
select: furnace setting (light lit).
Select temp of heat with the + or - buttons.
crunchman

[RvBill3]

X2

From a previous post of mine:

After setting fan to Au, use on-off switch to move to heat (or cool as the case may be) and select temp using + - keys. When heat is called for, furnace blower will start and AC will not.

When in cool mode, Au will cause fan to turn on and off with need for cooling. Other modes of fan (hi or lo) will cause fan to run constantly when cool mode is selected and only AC compressor will cycle on and off as needed. If the neighbors are making too much noise at night, set fan to lo and thermostat to cool. Instant "white noise" generator to mask the sounds outside.

[Cjhernandez]

Thank you both just saved my elderly parents from freezing and me from them. Worked great! What does the "au" means or does?
Another question, i turned the switch in the panel for water heater "on" but no hot water. What am I doing wrong?

[RvBill3]

Au for automatic. Fan turns on and off automatically with air conditioning. Not sure which water heater switch you mean. On the heater itself (accessible by removing the panel on the outside of the motorhome) the switch controls the electric element. Make sure the heater has water in it. You must be plugged into shore power or have generator running. Note the switch is mounted "upside down". Push in on the bottom of the switch to turn on. You will have hot water in about an hour. (There is also a circuit breaker that could be tripped inside). The other switch for water heater is located inside motorhome on control panel. This turns on the propane-powered burner. Propane tank must, of course, be turned on. Water in the hot water tank. Propane will heat water much quicker. Actually both electric and gas can be used together for quicker recovery. Normally if electric is available you will use that and save your propane. Note that if electric element is turned on with no water in tank, it will burn out in seconds and require replacement.

[Cjhernandez]

I had the one inside for over 24 hrs and nothing, will try the one by the heater out side. Thanks again.

[RvBill3]

Are you sure you have water in the tank? You should be able to lift up the pressure relief valve (located outside near the top of the tank) and have water come out. (Stand aside it will spray a little).

Also make sure the winterizing bypass valves are set correctly. On the back of the heater are three valves. They are accessible from inside. Don't know where on your model but look for a removable access panel inside directly "behind" your water heater. Two valves located on the water pipes going in and out of heater should be open (knobs parallel to pipe). A third valve located on a pipe between the in and out pipes should be closed (knob perpendicular to pipe).

Another thing to check is propane supply. Assuming the furnace is working and supplying heat would indicate good supply. But if you turned on water heater and there was excessive air in line it would have failed to light then turned off as a safety feature. Turning switch off for a couple of minutes then back on would retry lighting. Burner outside could also be dirty, have a spider web or other creature nest in it that is blocking gas flow.

[Cjhernandez]

Let me try this, got hot water with the switch on the outside flipped on(by the heater) but the one in the panel inside the unit got nothing.