Water Heater Pilot Won't Stay Lit

Users who are viewing this thread

Flaod

New Member
Messages
2
Reaction score
0
Points
1
Location
Florida
I recently had to turn off the main valve at my gas meter to cap an old buried gas line to my pool heater that rusted out and started leaking. When I turned the gas back on, the pilot lights for both my water heater and fireplace will not stay lit. I can get both to light up when I push down the pilot button, but as soon as I release it they both go out. Both were working properly prior to turning off the main gas valve. I did go ahead replace the thermocouple on the water heater but it is doing the same thing and I find it hard to believe that it is a coincidence that both appliances are doing the same thing. My gas furnace is firing up normally. What else could be the cause of this?
 

Terry

The Plumbing Wizard
Staff member
Messages
29,942
Reaction score
3,459
Points
113
Location
Bothell, Washington
Website
terrylove.com
The thermocouple needs to sense heat to allow the gas to stay on.
Light the pilot light and hold down the button for about a minute. You need to warm it up before letting go and rotating it to ON.

lighting-instruction.jpg


gas-thermostat.jpg
 
Last edited:

Flaod

New Member
Messages
2
Reaction score
0
Points
1
Location
Florida
I have tried several times holding it down for at least a minute or two and it will not stay lit on either appliance. When I first turned the gas back on I was able to get the water heater pilot to stay on and it did fire up and heat the water normally. But the next morning the pilot was out and I have not been able to get it to stay lit since
 

Reach4

Well-Known Member
Messages
38,858
Reaction score
4,428
Points
113
Location
IL
I have tried several times holding it down for at least a minute or two and it will not stay lit on either appliance. When I first turned the gas back on I was able to get the water heater pilot to stay on and it did fire up and heat the water normally. But the next morning the pilot was out and I have not been able to get it to stay lit since
If the thermocouple tip is not positioned in the flame, could you bend something?
 

Aaroninnh

Member
Messages
146
Reaction score
20
Points
18
Location
NH
Air in the lines? Can take a while to bleed that out with just a pilot.
 

Reach4

Well-Known Member
Messages
38,858
Reaction score
4,428
Points
113
Location
IL
Air in the lines? Can take a while to bleed that out with just a pilot.
If the pilot stays lit while you hold the button in, I wouldn't think that would be a problem.

What make and model?
 

Aaroninnh

Member
Messages
146
Reaction score
20
Points
18
Location
NH
If the pilot stays lit while you hold the button in, I wouldn't think that would be a problem.

What make and model?

Ive had it many times, air causes a weak wavy pilot that often doesnt have enough heat to keep the thermocouple warm.

Ive got a second story gas heater, and a range on the first floor with open pilots on the cooktop. When I shut the gas off in the winter (its a seasonal place) the gas spends all winter falling down from the second floor and leaking out the cooktop open pilots.

In spring when I go to light it, I get a week wavy pilot on the heater. Often it'll light but then go out a few minutes later and will take some time to get relit.

Just sounded similar to my issue.
 

Charley Highway

New Member
Messages
1
Reaction score
1
Points
3
Location
Texas
I recently had to turn off the main valve at my gas meter to cap an old buried gas line to my pool heater that rusted out and started leaking. When I turned the gas back on, the pilot lights for both my water heater and fireplace will not stay lit. I can get both to light up when I push down the pilot button, but as soon as I release it they both go out. Both were working properly prior to turning off the main gas valve. I did go ahead replace the thermocouple on the water heater but it is doing the same thing and I find it hard to believe that it is a coincidence that both appliances are doing the same thing. My gas furnace is firing up normally. What else could be the cause of this?
I had the similar problem couple of days ago.
Was what I would call as strange occurence, after starting heater, heater would shut off within a few minutes but relight and continue the shutting down issue afterwards.
Following advice from many forums indicating a faulty thermocoupling, I replaced the thermocoupling with a new one and results stayed exactly the same.
Turns out the bracket holding the thermocoupling in place at the correct distance from pilot had moved a bit apparently from a couple of years of thermal expansion and contraction- in short when the first shutdown occured there was a loud "pop" as if something had broken and -yes- the bracket moved just a small amount when this occurred, causing just enough diatance to allow the thermocoupling to heat sufficiently enabling start up but after a few minutes of cooler air drafting through the vent- to feed the flame- the thermocoupler was cooling off enough to break contact.
Heater works well now even with the older thermocoupling reinstalled (had to check it's condition out of couriosity) with no issues after readjusting but this was difficult to figure out since the bracket is not adjustable. The key indicator (for me)was the fact the lighter was close enough to become red hot after the flame out and restart each time. After readjusting the bracket (accomplished by causing enough tension with the copper tubes attached to thermocoupler to allow the bracket to remain in proper positioning), the lighter end is not discolored at all after start up and thermocoupler is in the correct close distance from pilot light to enable stable operation of the unit..
Hope this helps.
 
Last edited:

John Gayewski

In the Trades
Messages
4,346
Reaction score
1,340
Points
113
Location
Iowa
Your gas valve was affected by turning the gas on or off to quickly. Disconnecting the gas burner and pilot assembly blowing through it and making sure it's clean, purging gas through the pilot hole of the gas valve and disconnecting the gas valve and reattaching at the union lets me "reset" the gas valve.

Gas valves area very sensitive to pressure change.
 

Cuzzinred

New Member
Messages
15
Reaction score
1
Points
1
Location
Richburg SC
I recently had to turn off the main valve at my gas meter to cap an old buried gas line to my pool heater that rusted out and started leaking. When I turned the gas back on, the pilot lights for both my water heater and fireplace will not stay lit. I can get both to light up when I push down the pilot button, but as soon as I release it they both go out. Both were working properly prior to turning off the main gas valve. I did go ahead replace the thermocouple on the water heater but it is doing the same thing and I find it hard to believe that it is a coincidence that both appliances are doing the same thing. My gas furnace is firing up normally. What else could be the cause of this?

Is your pilot a stable blue flame or does it have a yellow tip ?
If it nice and blue, is the flame surrounding the top 1/3 or so of the tip of thermocouple ?
If it’s yellow tips, the pilot itself will need cleaning.
LP gas or Natural?
 

Dalton Bourne

New Member
Messages
8
Reaction score
0
Points
1
Location
Virginia
It would help if you made sure that the propane is flowing through the lines inside your oven. Using a lighter to ignite the pilot light immediately. Light RV water heater pilot may take more than 30 seconds to heat the thermocouple. the water heater’s pilot light is ignited, you should set it to just the right temperature and wait for a few minutes for your water to heat up.
 
Last edited:

NKaufman

Member
Messages
64
Reaction score
7
Points
8
Location
USA
I just experienced this the other day. Got a call from S.O. that there is no hot water.
Came home and found pilot light was out.
Tried to light it several times, On click the light would get lit but after several tries (each one in which I held down the switch longer than the previous one), the light would go out immediately.
Wiggled thermocouple very lightly and pilot light came on.

As soon as I put the cover back, the light went out as the cover touched wires and thermcouple and might have again messed up the position.

So repeated the above and cover is now on the floor ... Perhaps one day will try to put it back and see
 

Fitter30

Well-Known Member
Messages
4,343
Reaction score
794
Points
113
Location
Peace valley missouri
Check the clean the copper is and very end of the thermocouple. Thermocouple puts out 1/4 - 1/3 of a volt and needs to be snug in valve.
 

NKaufman

Member
Messages
64
Reaction score
7
Points
8
Location
USA
Hello,

I have a Bradford White Model - MI5036FB - Gas Water heater.

I had thermocouple replaced with a BW OEM thermocouple. Same issue as before, pilot lights up when switch depressed and goes out as soon as I release the switch, even after keeping it pressed for over 3 min.

before having it replaced, i was trying to put the cover back on and water heater turned off. While wiggling thermocouple and depressing switch and turning pilot on, one time I heard a 'boof', not very loud but loud enough (like someone passing gas) but it did blow some dust around, assuming some gas was trapped inside. Will that cause any issue?

With new thermocouple, I again wiggled it from the Gas Valve end and it seems to be working fine. Repairman thinks i need to replace Gas Valve. Any ideas?

Water heater is working now, will get him to put everything back and see.

Maybe it is the distance of thermocouple that is the issue like someone else mentioned and that could fix the issue.

BTW - what could cause that loud boof? am i correct in assuming residual gas etc. or does that indicate that gas valve could be faulty?

P.S. This could have been the high temp limit switch popping out if not excess gas trapped around?


Thanks
 
Last edited:

NKaufman

Member
Messages
64
Reaction score
7
Points
8
Location
USA
I'd been looking at this with the repairman.
With all the wiggling I was doing, he finally figured that the connection between thermocouple and gas valve wasn't getting tight enough. So he took it off, dropped the nut a few threads, wrapped some wire around the connection above the nut and then tightened it.
Seems to work.

Will check tomorrow and see if we still get hot water;)
 

Jeff H Young

In the Trades
Messages
8,888
Reaction score
2,218
Points
113
Location
92346
oh you have a repairman? if you are paying for his service it might be worth changing the valve but maybe its all warranty
 

NKaufman

Member
Messages
64
Reaction score
7
Points
8
Location
USA
He was doing something else and took a look at this for a nominal additional charge since he was already here.

No warranty... This is a 18 year old heater and I have no home warranty.
Might think of it since house is 18 years old and apart from roof, toilets, dishwasher, microwave, washer and dryer, everything is 18 years - fridge, oven. furnace, water heater.

Toilets I replaced recently after finding about Toto on this forum
 
Last edited:

Jeff H Young

In the Trades
Messages
8,888
Reaction score
2,218
Points
113
Location
92346
well I hope you are good for awhile 18 years is pretty good. might still have some years left
 

NKaufman

Member
Messages
64
Reaction score
7
Points
8
Location
USA
Checked water heater
seems to be working fine

Raised temp of water and burner came on immediately, turns off immediately when water temp lowered.
Will keep the forum informed so if this is really a fix then people can look into this before replacing Gas Valve etc.
 

Jeff H Young

In the Trades
Messages
8,888
Reaction score
2,218
Points
113
Location
92346
After your post 15 you said it was working fine im glad it works now but raising temp today has no effect on the piolet light staying on the last 15 hours or so, it should run for weeks/ monthes turned way down or on vacation or pilot mode
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks