Old floor furnace won't come on...

Old 10-28-09, 02:59 PM
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Unhappy Old floor furnace won't come on...

Well it's COLD! We lit the pilot light just fine and it is staying on. When we first lit the pilot light, the furnace did come on ONCE. Then it shut off before reaching the desired room temp, and we can not get it to come back on. Because of this we thought it might be the thermostat, so we also replaced it with a new one, still it will not come on no matter how high we turn the thermostat too. The floor furnace itself is very old, at least 50 years or more. We have never had a problem with it in the past. Any ideas?

Brrrrrrrrrrr, it may snow today.
Old 10-28-09, 04:05 PM
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Floor furnaces are commonly millivolt systems, powered by electricity generated firectly from the heat of the pilot flame.

If that's the case, you will find two wires with spade connectors on the end connected to the electric gas valve.

If that's the case, the most common cause of the problem you describe is a dirty pilot burner and pilot orifice --- that hasn't been cleaned in years.

Rather than burning like a small blowtorch, you will probably see the pilot burner with a soft, lazy flame more like a candle flame, perhaps with a good deal of yellow flame in it.

If that's the case, the pilot burner would need to be removed, disassembled and cleaned, especially the pilot orifice that can be accessed by loosening and removing the brass ferrule holding the .25" aluminum pilot gas tubing into the pilot burner.
Old 10-28-09, 04:11 PM
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When all else fails....stomp on the floor close to the furnace. If it comes on, SP is right on....I'm sure he is anyway.

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