Suburban Heater Blowing Cold Air occasionally

[Cody Madison]

Hi friends,

My propane Suburban heater blows cold air occasionally after heating for about about an hour. Is this normal protocol? Is the heater cooling its self?

That cold air isn't friendly when it's 12 degrees Fahrenheit and you live in an airstream like me.

Thank you for your time.

PS
My propane tanks are not empty.

[rmkrum]

It's probably gotten a little too hot internally, and the over temp switch opened. That cuts off the gas, but let's the blower run to cool the heat exchanger.

Check to see that there is nothing blocking heated air output or return air flow where it is mounted. It needs to breath freely.

Also check the external air intake and exhaust outside...it's just good practice in cold weather and for maintenance.


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[DKB_SATX]

There is a cool-down portion of the cycle that run after the thermostat opens. It may be that it's cold enough there that it cools off much quicker than it's designed for (after all, while the fan is running it's circulating outside air through the combustion-air side of the system as well as through the ducts within the trailer, so the heat exchanger probably cools off pretty quickly if it's 12F outside.)

Do you hear the thermostat click before the air turns cold? Does it do it at the end of every cycle or just sometimes, or do you only notice it if you're near one of the vents? Is this the original furnace with a pilot light or a replacement unit with spark ignition?

[HowieE]

That is completely normal. There is a purge cycle at the beginning and end of each heating cycle. Not the greatest for comfort n a small area but necessary for this type of heater to operate safely.