Suburan furnace?

Furnaces aren't designed to run 24/7. They're designed for a 1/3 duty cycle. Or 20 minutes out of each hour. Maybe up to 30 minutes/hr. or less.

A furnace running 24/7 is way over stressed and it's dangerous. The safety controls are designed for normal failures under normal conditions. NOT 24/7

In those conditions I would install a residential furnace. A horizontal 80,000 btu high efficiency with PVC intake & exhaust. It is only prohibited for MANUFACTURERS to install residential furnaces in campers. And that's because furnace manufacturers won't list mobile homes and RV's because they don't want the liability. A residential furnace is 100 times better. (and safer)

It will require adding duct work to handle the added air flow. It's not a do-it-yourself project. Temperature rise test MUST be made after installation to guarantee you haven restricted air flow over the heat exchanger.

I could get it done for a little over $400. You may need to pay someone. It's not the accepted conventional way to heat an RV. It's better. You'll go from a 60% efficiency to a 90+% efficient heating system. And be more comfortable.
I wouldn't make a point of telling my insurance agent. But on the bright side the chances of your camper burning to the ground will go from about 50-50 to zero. JMHO

IOWASTROKER wrote:
I have had to replace the blower motor in my 42K BTU furnace three times since '06. It runs 24/7 when 20 below zero and a 12-volt motor simply can't handle that abuse. Last time, I cleaned the burner orfices with a wire brush, possibly enlarging the openings cuz when it "lit" up, made more of a roaring noise. Now, it cycles like the high limit switch is NOT working. Anyone else have this kind of prob..and, if so, can I simply replace that switch and solve my problem OR what. Thx.

Ever thought of adding a second furnace, 42K is a large furnace, but then again -20 degrees is darn cold, I would assume full skirting. Six years of that type of duty, might be time for a new furnace.