Furnace has low heat output

[av2pilot]

With these cold temps the past few days I noticed that the furnace isn't putting out that much heat. It is on and running since there is air coming out of the registers and the flame is lit since heat is coming out the exhaust. Any ideas on where to look?

[1retired06]

Blockage in the ducting?

[psomers]

Check the heater exhaust on out side of camper. I fixed one several years ago that had very little hot air exhausting. There is a removable flue that dirt dobbers had built in. If you have the screen over the exhaust that will not be your problem.

[jimkottke]

make sure that the mud wasps have not made a nest through the vent.

[Irlpguy]

Have no idea what model of Montana you have but I would be suspicious of the flexible heat ducts and their connection to the heat exchanger on the furnace or where they are attached to the ducting. I believe if you have vents in the floor those are fed from the bottom of the heat exchanger and should not be a problem unless there is some material that Keystone did not remove in the ducting that might be limiting the flow of air.

Many have had problems with the attachment of the flexible ducts to the furnace and to the metal ducting not being properly installed allowing air to escape at that point.

I would think if there were any significant blockage in the exhaust vent the heater would overheat and be shut down by the high temp switch.

They are the most inefficient of furnaces, more heat goes out the exhaust than is kept in the heat exchanger for long enough to capture that and make use of it.

Good luck with the solution.

[DQDick]

I agree, it really sounds like you have one or more ducts disconnected and much of your heat is going into your underbelly.

[av2pilot]

Thanks for the replies. ... I'll check out out when I get home. ...I have a 3400rl