HELP!!! pilot keep going out

Unknown

HELP HELP HELP

I have a customer (lucky me, just one, HA) that is on a job site that has stumped all of us.

Here's the History:
Call comes in, 9 year old 40 gallon water heater, pilot is out. My customer goes out to the home and lights the pilot. Two days later, same problem. So the contractor installs a new thermocouple. Two days later, pilots out.

The HO and Contractor decide that due to the fact the 5 year, 40 gal, is almost twice it's warranty instead of installing a new gas valve they decide to install a new 40 gal water heater. Two days later, guess what, no pilot.

Bradfor White, oops, I mean the water heater company decides their sollution is to install another new water heater. So the contractor installs the new water heater. Two days later, guess what, no pilot.

They call me.

I find out the boiler, located 5 feet away is fine, gas pressure is 6", no additions or changes to home, no CO, normal draft one appliance running, normal draft two appliances running. No apparent problem.

We've had more then our share of high winds around here so I suggest, due to everything else being checked, to install a rain cap on the flue. Couldn't hurt, might help. Two days later, guess what, no pilot on the water heater.

So all this time, 9 years of no problems, no problem with the boiler but now all of a sudden the water heater pilot keeps going out.

Can anyone supply a solution?????????

thanks,

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ed wallace

pilot light

if indeed it is a down draft problem than the only suggestions i would have is a field control fan in a can wired so that it always runs or a direct vent water heater dont know if you can retro fit a water heater with an electronic ignition but it does indeed sound like a wind problem but just maybe something in gas line which is doubtful

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Dale

Pilot

I would put a manometer on the water heater inlet with just the pilot on and then see what the gas pressure goes to when the boiler starts. Is the boiler standing pilot also? If it's electronic ignition you could have a gas supply problem, ask the utility to set a pressure chart for a few days, sometimes oil in the main or service or meter gives intermittent pressure. I also think that wind is probably your problem, how is the chimney? Any change, or blockage. When wind is the issue sometimes something in the installed space has changed like a open door that increases draft. I would take out the water heater draft diverter and replace it with a Field barometric, that way wind can be pretty much ruled out as a cause. One more thing, with the heater running monitor the closed circuit millivolts at the thermoucouple junction, just to make sure the cold junction isn't getting too hot.

Unknown

Water Heater

Let us do a process of elimination.

1. Not likely the problem is the water heater as it happens no matter which water heater is installed.

2. What changes if any have happened recently to this dwelling. Exhaust all possiblities.

3. Have you had an increased growth of high trees around the property? This can cause a change in wind currents and cause a downdraft.

4. I assume because you said gas pressure was six (6) inches WC that this is a high pressure gas system into this house. If so it is vey unlikely that gas pressure is your problem. If it was other equipment would be affected. By the way pilots on boilers are not regulated they are on line pressure. Water heaters are total regulation so the pilot is regulated and that tends to make it more stable.

5. Has there been anything to cause a change in air pressure in this house to create the possibility of negative pressure causing a reverse chimney. Bring on every fan in the house close all the windows and doors. Bring on all the equipment in the house and with a draft gauge check the draft on vented equipment. The draft should be a negative .01 .02 inches WC. At the same time do a combustion test on all equipment into the chimney.

Now some questions:

1. What size flue is on the water heater?

2. Is this a center flue water heater?

3. Have they been using a fireplace at all during this time?

4. When if possible to know this does it go out? Daytime or night etc?

Now let me imagine myself to be this pilot, or these pilots. They are all in the same place with all things equal. The pilots are all doing the same thing. Other than all the things others have posted as a pilot I make my own products of combustion. Those products have to get out of the water heater. The draft needed is created by temperature differnce and height. If this is a standard water heater and is flued into a lined masonry chimney it has to create draft all by itself. If it does not it will recirculate products of combustion and literally snuff itself out. The pilot needs the vent to be pitched a 1/4" per foot, if it is a 3 inch vent increase it to 4 inch. An old rule if you can not get vent RISE then increase one SIZE. A lot of water heaters are flued directly into the chimney with an elbow right on top of the draft hood this gives no rise therefore we increase one size.

Another thing we used to do was put a thermal damper like an Ameritherm (not made anymore) in the flue this was a good way to prevent backdrafts and down drafts from affecting the pilot.

A note about draft hoods. The draft hoods on appliances are designed to with stand a certain amount of back draft. If you use a barometric make sure the water heater manufacturer gives you written permission to do that. Also make sure you use a double swing baromteric.

Last of all try introducing some outdoor air, leave a window open for a few days and see if it helps. If it does then you may need to have a dedicated outdoor air opening into this area. I would suggest using the new method 2 in National Fuel Gas Code with air change per hour tables. Method two sort of eliminates cold air coming in 24/7 and it allows air only when the equipment is on and running.

Herb

pilot outage

Another obscure problem could be and undersized water heater with winter temperature water coming to the water heater. If after long draw down, the tank's hot water is depleted enough to cause the products of combustion to condense inside the water heater. The pilot could be knocked out by a drip of condensate. Just a thought, good luck Herb

ScottHVAC

There may be a gas supply problem - start all of the appliances using gas and then measure the supply pressure to the gas valve, and if you can, take it on the outlet to the burner and make sure they are still correct. Also, try opening and closing some doors with all theis going on and see if anything happens. Basically, try to create any condition which may contibute to the pilot going out.

Mark_4

O.K. ,O.K. don't pick on us plumbers . I have a suggestion..... Do a smoke test on the waste & vent system. If there are any breaks or corrosion holes located in the lines anywhere near the burners, the methane gas could be starving the pilot of oxygen. I had a very similar situation one time. After the Lucky Plumber who installed the first & second water heater, I was called to try to figure out the problem.The gas regulator was bad , & the utility co. replaced it , but still (not as often) the pilot light would go out . When I was down relighting the pilot , I became light headed. Long story short we found boo-koo leaks in the copper waste & vent lines .... once repaired , never another pilot outage. good luck! & keep us posted. MarkL

gas man

pilot outage

does the boiler have electronic ignition ? any moisture on top of the w.h. burner ? (didn't metion it so I thought i'd ask ! reason why I ask about a live pilot on the boiler is that the gas meter or regulator may have a moisture problem , and freezing up on the cold nites. if boiler pilot stays' lit -not the case ! check the meter fit for visible ice building -up ! if water heater is the only pilot in the home , I'd get the utility to change both the meter and the regulator .

c-rex

My dad

had this problem, well it sounds the same.
Are there kids in the house?
A gob of clear nail polish on the gas cock solved the problem after six call backs. Yup, it was an in house problem!

Unknown

THANK YOU

Wow! A lot of items that I never considered.

We ruled out all so far except this will be this weeks course of action:

(1) Look at drains. Seems there is an exposed drain line that had something connected to it at one time.

(2) gas company will be contacted to put a recorder o the line.

I'll let you know the out come.

THANKS everyone!!!!

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