thermo coupler on the blink?

[KHarris]

We had the original furnace in our 69 Caravel rebuilt this winter. It worked great during several at home tests , but on our first trip last week we were in lake Powell during unusually cold conditions, and what do you know...the thermo coupler wouldn't take. We thought it had gone bad, but as soon as we got back home we tested it again and it lit right up. Any ideas to the problem or possible solutions?

thanks, Krista

[TomW]

In cold weather, my furnace's pilot light takes A LOT of time to to get going. I believe the cold weather works against gas appliances in two ways: The gas itself is harder to light, and the thermocouple takes longer to heat to output maximum voltage.

My solution is a propane torch. While its use looks like overkill on a grand scale, in cold weather the torch will light when "propane matches" (click & hold BBQ grill lighters) will not.

BTW, what all did your furnace's rebuild include?

Tom

[lewster]

Sometimes, especially in cold weather, the thermocouple will take longer to heat up, reach operating temp and generate the proper voltage to work properly. Your idea of a BBQ lighter or butane 'match' left on the pilot area to heat up the t/couple will often work in getting the furnace to ignite.

[KHarris]

I should clarify that, we have the original Hydro Flame, and we discussed replacing it with a newer model heater, but a certified RV repairman recommended first trying to clean the original one up and see how it worked. He got it working and thought it was a good reliable heater, so basically he blew it out with a compressor and cleaned up any rust and debris. We haven't had a lot of time to test it, but it's nice and quiet and has fired up quickly on previuos at home tests. Sounds like we really need to heat up the thermo coupler in cold windy weather.