Pilot light keeps blowing out, Help.
Ledebuhr1
| Posted in Energy, Heating & Insulation on
Have a neighbor that has had the pilot light in the Hot water heater blowing out, especially durring high winds. The vent stack is double lined pipe that is punched through the roof. The vent has a cap on it and sticks out of the roof a couple feet. Any ideas as to why the pilot light keeps going out?? espically in high winds. and how can we change it?? thanks
Replies
When that happened to me, the controller had gone bad and was just not sending enough gas to the pilot light. So yes, it was blowing out in high winds, but no higher than the winds it successfully withstood before it wore out and after it was fixed.
Other possibilities might be of more concern.
There is supposed to be a gap between the top of the water heater and the flue bonnet which is intended to prevent backdrafting from blowing the pilot light out. Is that gap there? Is it the right bonnet? (I sometimes see a bonnet from the prior water heater mismatched to a newre water heater.)
Look at the top of the water heater around and under the bonnet. Is there a lot of rust or debris or soot? That often indicates draft problems.
Is the top of the flue 2' above anything within 10'?
Is there sufficient make up air to support combustion? Add the water heater and furnace/boiler btu's together, divide by 1,000 and multiply by 50. Are there that many cubic feet in the utility area. (You'll need more if there's a dryer in that area.) Is something else creating negative pressure in the utility area?
Backdrfating problems can be associated with (or even cause) high carbon monoxide levels in the house. Get the situation fixed!
All good points. I just assumed without asking that it was an existing installation that had recently started misbehaving.
So, yeah! What Bob said.
thanks,
Yes the HWH does have the bonnet that is about 2" on top of the hWh. I will check the height of the vent to see if the are 2' above anything within 10'.
It very well might be the controller.
I had the same problem a many years back. Played with it myself for a while then hired someone who replaced the thermocouple for a measly $4 million or something close to that. Results? Problem solved. Since then I have replaced a few other thermocouples myself. Results each time? Problem solved. It would seem that the thermocouple unit develops a leak which causes it to exert a slightly less pressure on the safety shutoff valve, lowering the gas flow to the pilot light , and thus making it easier for to be blown out, or it just may be that the appliance is a female and you have not been giving it enough attention.