furnace pilot goes out???

[Cory Lechner]

I have had to start the pilot on our furnace twice today! Any ideas why? I had to re-light it a while back as well (couple of months ago)...

Cory

[TURTLE]

This is Turtle.

When a person says what you say here. It usely is 1 of three things.

1) weak thermocouple mill-voltage from it.

2) Pilot lite jet clogged up or stopped up and not letting flames hit the thermocouple right.

3) You have a hole in the fire chamber and it is blowing back out to blow flames out of the pilot lite on certain times but just at certain times. The beginning of a problem.

TURTLE

[Joseph Meehan]

I will add one more.

Turtle's 1, 2 and 3 are in order of likelihood. Mine would be #4 as it is unlikely. A strange downdraft from the vent can cause it as well, especially if it is cold. I had this once many years ago on a water heater. It drove me and the service man (new water heater) crazy for several weeks until he figured it out.

[jim]

probably that the pilot light is not big enough(the reason for this is dirt gets over the pilot area and blocks the flow of gas at the pilot.. get a large refrigerator brush and with the pilot light off brush the area right above the pilot light.... then relight it and no more problems(unless the pilot needs adjustment???)....

[Cory Lechner]

[Cory Lechner]

when I light the pilot light, the flame is quite large (2 inches) ....

[CBhvac]

If you have a good flame on the pilot, and its only covering the top 1.3rd or so of the thermocouple like it should, then you more than likely have a bad thermocouple that is dropping voltage to the gas valve. It is VERY common, and a quick fix is to go to Lowes, or Home Depot and buy a new one..or two as cheap as they are there. The reason I say two, is that Honeywell is suppling them with a VERY cheap grade thermocouple and you might find yourself in a month or so with another bad one. The most expensive one they sell is about $6. The cheapest we sell is about $19 wholesale...Being that its Sunday, you wont find a Johnstone open that will sell you a good one..and even if it was Monday, it might prove to be hard to get one from a wholesaler anyway...maybe not..depends on your area.

Turtles post pretty much covered the bases.....worst case senario is a cracked heat exchanger that is allowing the blower to get air into the exchanger and blows the pilot out after the call for heat is over. It also could be a bad gas valve that the pick and hold solienoid is going bad, and then, the only fix would be a new TC and gas valve.

[Des Perado]

Was it windy out when you pilot light went out? I had a water heater some years back on which the pilot light would often extinguish during a wind storm. This usually happened at nite with the result of no hot water for a shower in the morning. I asked several people in the plumbing and heating business about it, they all had ideas of what it might be, but none of them seemed plausible to me. Some years later, the hot water heater met it's end and I installed a new one. Never had it happen again and it must be five years now. For what it's worth, Des.

[TURTLE]

this is Turtle.

i would not discount this problem at all for it does happen on some jobs. I have seen 3 jobs in the last 5 years that this was the problem on gas standing pilot lite going out.

TURTLE

[Cory Lechner]

So I would have to remove the burner so that I can replace the thermocouple? Is there a way to find out if the thermocouple is bad before I buy it? I have a "Inter-City" furnace, model 100 GAB (manufactured in Winnipeg, Manitoba) - any good websites on how to remove the thermocouple and burner from this type of furnace?

Cory Regina, Saskatchewan

[Tony Hwang]

Hi, Some times the thermocouple connection to the main gas valve gets loose. Unscrew and disconnect it, make sure the contact is clean and screw it back in tight. Also flame size can be adjusted. Tony

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[CBhvac]

thermocouple?

No. You find out if the thermocouple is a screw in, or a push in type at the burner, and remove it accordingly.

With a DMM that reads millivolts...

None that I personally reccomend. Replacement of the thermocouple is one of the simplist repairs to a unit....not being a smartass, but if you cant figure it out, a website for sure wont help you.

[Cory Lechner]

It appears to be somewhat hard to get at... without removing the burner...

I have a digital mutlitester, will this work?

in

[CBhvac]

Some are a pain...some are what look to be a pain but can be done...others...well....someone needed to shoot the idiot that designed it... Carrier, and Tempstar....both are some that had some real design issues..

Does it read millivolts? If so, it will work.

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