# Possible reasons for extinguished pilot?



## smellslike$tome (Jun 16, 2008)

Roughly 2.5 years ago I installed a 50 gal Rheem ng Pro Series wh for a very good client. We got a call a while back, not sure how long ago but could have been a year or so, about no hot water. I went and discovered that the pilot was out. Re-lit pilot with no trouble and everything was fine. Last night we got the same call again, on the same water heater, and again, I re-lit the pilot with no trouble. It was late so I didn't attempt any diagnostic but will be returning at my first opportunity to check it out more thouroughly. When the call first came in yesterday evening, I went ahead and called Rheem who couldn't really offer any decent explanation. Thinking about the possibilities, all I can come up with are the following:

1. low gas pressure - I will be testing it but I doubt this is it. If this were it I would expect failure much more often than twice in 2.5 years. 

2. restricted or insufficient combustion air - the wh sits next to a ng furnace in a finished basement which by volume should be more than sufficient. This one was suggested by Rheem. There are two pieces of furniture, a china cabinet, and a small cabinet (about 4' tall sitting on the floor) that more or less "enclose" the area where the wh and furnace are located. The furniture sits at right angles to each other with plenty of space above and enough space so that you could easily walk through to the wh and furnace. I really don't see a restriction in flow and seriously doubt that the problem has anything to do with combustion air.

3. The customer asked about the thermocouple but I have never seen one failed that didn't do so catastrophically. In my experience they either work or they don't and two failures spaced over a year or so suggests to me that there is no problem with the thermocouple.

4. Condensation - the vent clearances were very tight on this water heater, resulting in minimum rise for about 4' from the wh to the connection to the furnace. When the unit fires you can hear the condensate start sizzling on top of the burner within a couple of minutes. I would think that even if condensate somehow was hitting the pilot, a lit burner would simply reignite the pilot before the whole thing went out. If it were condensate related it would seem like it would have to be happening after the flue was hot and after the burner shut off. I'm reaching here I know. I asked Rheem about this and they said that it could happen sometimes and that the fix is to rotate the baffle inside the flue a few degrees to redirect where the condensate is dripping down into the combustion chamber.

I really don't have a lot of faith in any of these possibilities. If I can somehow recreate the event then maybe I can get a handle on it.

Any suggestions, anything I'm over looking?

I will go back later this week and check everything out more thoroughly. The first time it failed I simply relit it and thought "hmm that's odd". It may just be some freak thing but I doubt that too. There is always a reason for everything.


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## Titan Plumbing (Oct 8, 2009)

I'm tagging, I have a A.O. Smith with the same situation, Smell.

I personally think it has to do with combustion air, due to the FVIR filter stopping up.


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## SlickRick (Sep 3, 2009)

99 % around here have been combustion air issues. Dust on the screens etc. With a few bad control valves. Lack of air shut down, resets relight, last awhile does it again. Some have been more tempremental (sp) than others..


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## Christina (Jul 14, 2009)

smellslike$tome said:


> 4. Condensation - the vent clearances were very tight on this water heater, resulting in minimum rise for about 4' from the wh to the connection to the furnace. When the unit fires you can hear the condensate start sizzling on top of the burner within a couple of minutes. I would think that even if condensate somehow was hitting the pilot, a lit burner would simply reignite the pilot before the whole thing went out. If it were condensate related it would seem like it would have to be happening after the flue was hot and after the burner shut off. I'm reaching here I know. I asked Rheem about this and they said that it could happen sometimes and that the fix is to rotate the baffle inside the flue a few degrees to redirect where the condensate is dripping down into the combustion chamber.


Smells, we have had the same issue twice now. 

Winter 2007- My father had went over and lit a water heater 3 times one week. Thinking it was just a fast relight and that maybe the draft in the garage was possible blowing out the pilot? The last time he went he changed the thermocouple. He called me one morning and instructed me to go lay in front of the water heater until it went out. I layed in front of the water heater for about 20 minutes. The condensate from the flue would drip down and hit the thermocouple; shutting off the entire valve. On this one, someone had tampered with the water heater (possibly a homeowner trying to light their own) and the burner was off of center (barely) but was enough space that the condensate would hit the thermocouple and shut down the water heater.

A month ago- I went over and relit a customer's water heater after the hvac men had failed to relight all gas fixtures. Two weeks ago my father was called to come in after the hvac men had came and did some 'adjustments' to the cha new system. Just last week the customer called and she had to relight her water heater every morning but could never get 'hot' water. It seemed that the hvac had tampered with the pilot assembly. It was bent to where the thermocouple was barely in the flame and was bent back toward the door... just enough to where when the condensate on the flue began (BAM!) it would hit the thermocouple and shut the heater down. I replaced the thermocouple bent to pilot assembly back into place (to the best of where I could tell it went) and have not had a problem since.

Both of these water heaters were in clean areas with plenty of combustion air.

My point is... the pilot assembly being off just a minimal of space can cause big problems. Just one small drip of water on the thermocouple will shut the water heater down. Sounds like you may need to babysit a water heater for a bit.


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## TheMaster (Jun 12, 2009)

I'm casting my vote for a loose thermocouple connection at the control.


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## Regulator (Aug 20, 2009)

This is probably not the problem you are experiencing, but it is relevant to the thread in any case.

Pilot light kept failing constantly on a commercial HWT despite thermopile & gas valve proving out OK. The mechanical room was in the U/G parkade. The lower F/A inlet to the mech room was located 1 foot or so above the floor at the back of a parking stall. The HWT was in close proximity to the F/A inlet. This had me stimied until one day I was at the HWT again when owner of the paking parking stall was getting into his car. I had just re-lit the pilot and was observing it. The driver started the engine and it went to hi-idle. I started to get the exhaust in my face as I watched the pilot. Then the driver gunned the engine and poof! Out goes the pilot. Problem diagnosed.
Installed a tin deflector at the F/A inlet to divert the air flow from going directly to the burner area of the HWT. Problem solved.


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## SlickRick (Sep 3, 2009)

Take a sleeping bag...Im' just sayin'™


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## TheMaster (Jun 12, 2009)

The probem now coud be totally different than the 1st time a year ago when you went out and re-lit it. Hey I have had strong wind blow pilots out. You coud always shotgun repair it and replace the control and burner assembly.


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## futz (Sep 17, 2009)

I would change the thermocouple just in case (they're cheap), but put a meter on it and see if you're getting good voltage out of it. A mis-aimed flame (from a bit of dirt or something) can sometimes be not noticed from the angle you're looking at it. Make sure you're getting at least 24mV out of it. If not, pull the burner, clean the orifice, check for proper impingement.


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## tnoisaw (Jun 16, 2009)

I came across something like this a few years ago. It turned out to be wind going down the stack which only happened on certain days with the wind just right (wrong in this case).


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## Protech (Sep 22, 2008)

option 2


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## gladerunner (Jan 24, 2009)

My vote is for down draft knocking out the pilot, but also check if the gas company has been doing any work in the area, hwh are about the only things left with pilots, if air get in the line it could be enough to knock out the pilot


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## leak1 (Mar 25, 2009)

i had a problem with a water heater once like that and pulled out my hair trying to figure it out! changed therm- coup, change burner and control , check gas press. no luck. finelly went out to meter setting and removed a mud wasp nest out of the regulator vent.


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## futz (Sep 17, 2009)

leak1 said:


> i had a problem with a water heater once like that and pulled out my hair trying to figure it out! changed therm- coup, change burner and control , check gas press. no luck. finelly went out to meter setting and removed a mud wasp nest out of the regulator vent.


I've seen that twice at a friend's house. Boiler and HWT pilots go out - hmm... check the reg again. More bugs!!!


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## para1 (Jun 17, 2008)

slickrick said:


> 99 % around here have been combustion air issues. Dust on the screens etc. With a few bad control valves. Lack of air shut down, resets relight, last awhile does it again. Some have been more tempremental (sp) than others..


L.A.S.D. (lack of air shut down) I like that, will add to book.:thumbsup:


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## Regulator (Aug 20, 2009)

Thermocouple diagnostic tool - inexpensive & effective. Allows you to measure actual voltage under load.


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## SlickRick (Sep 3, 2009)

para1 said:


> L.A.S.D. (lack of air shut down) I like that, will add to book.:thumbsup:


I forgot to put a coma in there! What a ******* accronym..:laughing:


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## TheMaster (Jun 12, 2009)

Regulator said:


> Thermocouple diagnostic tool - inexpensive & effective. Allows you to measure actual voltage under load.


 That is not the prefered method for a white-rodgers control.


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## Regulator (Aug 20, 2009)

TheMaster said:


> That is not the prefered method for a white-rodgers control.


Maybe not, I wouldn't know about that. :confused1: 

Thanks for the correction, but it works great for most applications where a threaded thermocouple is used. :thumbup:

I guess I'm just too old school for some of the latest products out there. :wheelchair:


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## Christina (Jul 14, 2009)

_smellslike$tome_ 

So, what was the problem? Have you diagnosed the water heater? What was wrong? Was it a small oversight? Was it the thermocouple? Was it the wind? You are killing us... WHAT WAS IT?


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## smellslike$tome (Jun 16, 2008)

Ho was out of town late last week and couldn't keep appointment. Rescheduled for tomorrow, a.m. I'll let you know.


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## smellslike$tome (Jun 16, 2008)

Christina said:


> Smells, we have had the same issue twice now.
> 
> Winter 2007- My father had went over and lit a water heater 3 times one week. Thinking it was just a fast relight and that maybe the draft in the garage was possible blowing out the pilot? The last time he went he changed the thermocouple. He called me one morning and instructed me to go lay in front of the water heater until it went out. I layed in front of the water heater for about 20 minutes. The condensate from the flue would drip down and hit the thermocouple; shutting off the entire valve. On this one, someone had tampered with the water heater (possibly a homeowner trying to light their own) and the burner was off of center (barely) but was enough space that the condensate would hit the thermocouple and shut down the water heater.
> 
> ...


Ding, ding, ding, ding, ding, we have a winner! 

At least I'm pretty sure we do. I was leaning toward condensation but couldn't quite put it all together. Today I went back and shined a light in through the view port and sure enough the burner was cocked. Pulled the burner assembly and the condensate rust trail led to within about an inch and a half of where the pilot is located. This is why it happens so rarely (twice in 2.5 years) it doesn't drip directly on the pilot but every now and then water is running around the outer edge of the burner, being held in tension, until it drops on the pilot and poof, out she goes. I tweaked the burner assembly until if anything it leans slightly toward the back of the combustion chamber. I'm pretty sure this is it. I guess only time will tell.

Thanks Christina.


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## Christina (Jul 14, 2009)

smellslike$tome said:


> Thanks Christina.


*Anytime smellslike$t:thumbsup:me!*


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## TheMaster (Jun 12, 2009)

smellslike$tome said:


> Ding, ding, ding, ding, ding, we have a winner!
> 
> At least I'm pretty sure we do. I was leaning toward condensation but couldn't quite put it all together. Today I went back and shined a light in through the view port and sure enough the burner was cocked. Pulled the burner assembly and the condensate rust trail led to within about an inch and a half of where the pilot is located. This is why it happens so rarely (twice in 2.5 years) it doesn't drip directly on the pilot but every now and then water is running around the outer edge of the burner, being held in tension, until it drops on the pilot and poof, out she goes. I tweaked the burner assembly until if anything it leans slightly toward the back of the combustion chamber. I'm pretty sure this is it. I guess only time will tell.
> 
> Thanks Christina.


 Everytime i try to look through the glass with a flashlight all I see is an ugly plumber staring back at me. What kinda flashlight do you use...i might need to get one:thumbsup:


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## stewart (Nov 4, 2009)

if your water heater is manufacture in 02 or newer and made by a.o.smith state or whirlpool. cleaning the screen should be done at lease twice a year. they make a brush that attaches to a vacuum cleaner to make it a very easy job. tightspotvacuum.com


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## TheMaster (Jun 12, 2009)

stewart said:


> if your water heater is manufacture in 02 or newer and made by a.o.smith state or whirlpool. cleaning the screen should be done at lease twice a year. they make a brush that attaches to a vacuum cleaner to make it a very easy job. tightspotvacuum.com


 I have one of those and they blow harder than the suck:laughing:


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## smellslike$tome (Jun 16, 2008)

stewart said:


> if Your Water Heater Is Manufacture In 02 Or Newer And Made By A.o.smith State Or Whirlpool. Cleaning The Screen Should Be Done At Lease Twice A Year. They Make A Brush That Attaches To A Vacuum Cleaner To Make It A Very Easy Job. Tightspotvacuum.com


spamola!!!


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## smellslike$tome (Jun 16, 2008)

TheMaster said:


> Everytime i try to look through the glass with a flashlight all I see is an ugly plumber staring back at me. What kinda flashlight do you use...i might need to get one:thumbsup:


Yeah it's not easy. You have to hold it at just the right angle and even then you can't see everything. I actually use a Ryobi from HD, ... that's right I said it, it came from HD. 













Oh, ... the shame.


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## SlickRick (Sep 3, 2009)

stewart said:


> if your water heater is manufacture in 02 or newer and made by a.o.smith state or whirlpool. cleaning the screen should be done at lease twice a year. they make a brush that attaches to a vacuum cleaner to make it a very easy job. tightspotvacuum.com


stewart , did I miss your intro?


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## Protech (Sep 22, 2008)

stewart said:


> if your water heater is manufacture in 02 or newer and made by a.o.smith state or whirlpool. cleaning the screen should be done at lease twice a year. they make a brush that attaches to a vacuum cleaner to make it a very easy job. tightspotvacuum.com


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## Pipedoc (Jun 14, 2009)

Good one Protech!


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## Pipedoc (Jun 14, 2009)

stewart said:


> if your water heater is manufacture in 02 or newer and made by a.o.smith state or whirlpool. cleaning the screen should be done at lease twice a year. they make a brush that attaches to a vacuum cleaner to make it a very easy job. tightspotvacuum.com


Too bad they don't answer their phone.


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## RealLivePlumber (Jun 22, 2008)

Since Stewie can't read, and has no freakin' respect, now no member from this site will ever purchase one of his cheesy a$$ brushes. 

We will also recomend to everyone we know and meet not to purchase one of his cheesy a$$ brushes.:no:


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## pauliplumber (Feb 9, 2009)

Unless of course he sends us all one for free. We can test it, and if we like it, we'll recomend it. Give away a hundred and you might sell a million.....


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## Ashleymc (Nov 14, 2009)

Id go with failing/faulty gas valve..IF i had already changed the thermocouple once.
These newer sealed combustion units are good for business..UNLESS youre the one that put it in months ago!!

Hey-On that millivoltage test ..do u put meter on milli amps -one lead to ground ,other to gas valve end of t-couple??? and it should read at least 24??


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## Ron (Jun 12, 2008)

stewart said:


> if your water heater is manufacture in 02 or newer and made by a.o.smith state or whirlpool. cleaning the screen should be done at lease twice a year. they make a brush that attaches to a vacuum cleaner to make it a very easy job. tightspotvacuum.com


Banned for spamming our site.


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