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I have a sterling overhead heater QVF-75.Pilot fires up and main burners also.Fan does not start.I took fan off and found will run with direct power.I took thermal couple off and tested and it opens and closes.There is a limit switch(terminology may not be correct).L8947.Is this where my problem lies?

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It's called the blower activation switch. It turns the blower on, when the heater reaches the proper temperature. The Thermocouple has nothing what-so-ever to do with the blower. It's simply a safety device for when the pilot goes out for some reason, it stops the gas from reaching the pilot. In other words, it locks up the gas control valve.

Most of the time, a "Limit Switch" stops the heater form overheating by shutting it down. However , these Sterling Heaters can be a little strange at times and what I would consider a limit switch, could be something different for Sterling. Check you Owners Manual to see what Sterling means by Limit Switch.

Hope this helps you to further troubleshoot the problem.

Posted on Apr 07, 2011


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