# Pilot light for furnace how much does it cost to keep lit



## scfa99 (Dec 11, 2007)

Alright I know this is a strange question but I've had 2 people tell me they shut off the pilot light on their furnace (when not in use) to save money on propane.  Any idea on what this could cost a month to keep lit?  I never really gave it much thought but it can't be more than a couple bucks a years to keep the pilot on...  or am I wrong?


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## Metal (Dec 11, 2007)

On gas fireplaces I have heard estimates that half the gas used if for keeping the pilot light on year round (as most are seldom used).  The only negative I have heard is that the orifice can be plugged by spider mites while it is shut off.  My furnace doesn't use a pilot light (has an electronic igniter) but I do shut off the pilot light in my gas fireplace and plug the flue (haven't used it in over 2 years as it is highly inefficient).


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## Corey (Dec 12, 2007)

That is a good question - my furnace pilot has been out since last March.  I think they vary quite a bit - when I first moved in (and knew the previous owner had $300-350 gas bills) I gave the furnace the once over.  The pilot was about a 3" long flame with a clearly audible hissing / wooshing sound.  A little cleaning and adjusting brought that down to a 1" flame with a barely audible hiss.  I also sealed up the amateur installed register that was tapped directly into the plenum and dumping air into the basement and adjusted the cycle time of the furnace so it would run more than 3 minutes at a time.  All that got the gas bill down to $90-100 for the same period of the next year.  But never measured the pilot independently.

I have seen quotes of 5-12 therms (aka ~ hundred cubic feet, ccf) per month for older furnaces

http://www.clarkpublicutilities.com/Residential/TheEnergyAdviser/06_03_26

I think my current price is about 1.30-1.40 per ccf, so maybe $7-16 per month.  Not the most expensive thing I've ever paid for, but why burn over $190/yr if I don't have to.


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