Water heater pilot light goes out when burners go out

Jan 02, 2004 Last reply: 4 years ago 38 Replies

I just started having a problem with my gas water heater where the pilot light would go out after a while. The thermocoupler was replaced and the problem still occurs. The pilot light can be lit and stays lit till the main burners turn on, but when the burners go off, so does the pilot light. I used a video camera to verify this.



Any suggestions?



Thanks!



Tai


1) Make sure the door to the burner compartment is replaced tightly so no air can rush in or out. I'm assuming the pilot light is close the door opening. 2) If this is not the case, see if there is anyway to adjust the pilot light. 3) If 2) is not possible, as the pilot light is lit., use a screwdriver or something to tap the pilot gas line. Natural gas is pretty dirty and maybe there is junk suck in the line.

Good luck.

Tai wrote:

Today's heaters use very small pilot flames, which are easily "blown out" by the puff created when the main burner goes off.

*If* that's the cause, some gas controls have a pilot adjustment; many do not. In that case, the pilot burner has to come out to be cleaned (orifice).

A baffle plate (behind the access door) could also be installed incorrectly, allowing a draft over the pilot.

Probably least likely is an internal problem in the gas control (regulator). Jim

It may be possible to do some adjusting of the main burner air mix. Make sure the flame of the main burner is blue with maybe just a slight bit if yellow mixed in. My guess is as Jim suggested the puff that occurs when the main burner turns off is blowing the pilot out.

If it's only 1.5" wide, I doubt you'll see much shrinkage, esp. if you used dried lumber. If not, first give it a chance to dry.

pb

Apologies, sent this to the wrong thread!

pb

any time i had problems with a pilot light going out, this is what i first did... let the light stay out and take a tooth brush an taped a dowel onto it to make it easy to use.. then went in there and gave the pilot a good scrubbing.. it knocked the dust/dirt off the pilot and then light the pilot and bet it is not bigger and brighter????? its the dirt thats stopping the pilot from burning bright and big... the dirt blocks the gas flow so you get a smaller pilot and it blows out pretty easy... it worked for me in the hot water heater, the oven, and the central heat system.... hope it works for you...'

Thanks, everyone, for your suggestions. I cleaned out the gas line for the pilot lit and sealed up a joint where there was a leak and that seemed to increase the size of the pilot flame. The pilot still went out till I left the cover plate off the heater wall and left the door to the closet opened. One or the other must be affecting the flame. It's been working fine for a few days so I'm going to give it a few more days then put the cover plate back on and see if the pilot goes out again. If it doesn't I'll wait awhile and then close the closet door.

Weird that the flame goes out with more possibilities of draft, but I can't argue with what I see.

Again, thanks for all the suggestions.

Tai

Makes me wonder. First, is that WH the only gas appliance in the room? Do you have some sort of make-up air available? You could have a dangerous situation here.

hey if it goes out when you close the door, where does it get the air??? to burn???/ that might be why the flame is going out???? does it have a vent to let the frumes from the burning go up and out??? it should, try checking the pipers to make sure the fumes go up.. might be a dead bird or such up there and thats i why its starving for air and goes out///

The water heater is in my garage. About ten feet away is my furnace. It's a 2-car garage. Both the furnace and WH normally behind closet doors that has vent openings on them. They've been working well like that for at least 5.5 years. Don't know what changed.

Tai

There are some vents on two places on the closet door to let air in. I also thought it could be the exhaust air outlet so one time when the heater was turned off, I lit a match, put it out, and the smoke did suck into the heater compartment towards the center of the heater. So there is SOME air being drawn out. There may still be some constiction that affects the heater when it's fully on. Not sure how to check for that. I guess I'll climb on the roof and take off the vent cover and see if I can look down into it.

Tai

Exactly what’s happening to ours ,any recommendations to fixing it ?

Could be a bad thermocouple. Reasonably cheap and easy to replace. About $15.

The combustion chamber is overheating and the thermal shut off is cutting the gas supply. some automatically reset when it cools down and the pilot light can be relit easily, then the burner fires and the cycle starts all over again.

Mine would light at night and be out in the morning. I vacuumed the bottom of the tank and it started running again.

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Just an example of what I am talking about.

Replace the pilot thermocouple. (Clwaning and adjusting MIGHT help - but wouldn't count on it)

Yeah, but not if you're out of town. What are the chances a water heater could a) freeze, or b) freeze and break, in an unheated below-ground basement? Only about a foot of the basement is above ground level, and there is only one small window, in the other room from the WH.

In chicago and in Baltimore?

I'm leaving in a week for 4 months and have to decide whether to turn my water heater off.

OTOH, how much will it cost to run an electic water heater for 4 months if no one uses any water?

No clue what this has to do with the original question and how many electric tanks have a combustion chamber, or more simply why are you comparing apples to oranges?

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