Gas Water Heater Problem

[kaneohe]

Normally when we go on vacation, I turn our gas water heater to pilot.
Just noticed there is a low temp part of the control marked vacation which,
I assume , means it's more normal just to turn the temp way down......but historically I haven't done that.......just have turned to pilot and left temp control alone. Have done that for many yrs w/o incident.

This last wk when we returned I turned from pilot to ON. There was a loud sound and a momentary flash so I turned to pilot, then OFF; also turn temp control to minimum. I then relit the pilot, turned to ON, then turned temp control to normal w/o incident.

Today, 2 days later, I found the pilot off. It seemed to take repeated attempts to light the pilot, waiting in between before the next attempt. I finally got it lit, installed the 2 doors, then turned ON and then turned the temp dial to normal. Again that same loud sound and flash. Turned it OFF again and waiting to try again.

2nd try today. Lit pilot ok. Put 2 doors back . Turned ON and slowly increased temp dial. Somewhat loud sound when main burner came on , ran for a few minutes, but then flame went out by itself. I had tentatively concluded that TC was because pilot stayed lit.
....but can TC fail w/ increased heat when main burner comes on?

What is the problem? Is it on last legs and should be replaced? Water heater is almost 10 yrs old.

 

[W2R]

Apparently the average lifespan for a gas water heater is maybe 10 years, give or take a couple of years. So, that might be something to consider right now.

 

[bUU]

I actually couldn't get a gas-fired water heater with a 9 year warranty last time our water heater went... the only option any of the stores or plumbers I checked with would offer was a 6 year warranty. Crap gets crappier.

 

[kaneohe]

Thanks, W2R and bUU , for your street-smarts and wisdom. IIRC , this is the 1st replacement so the original last 29+ yrs and this one 10- yrs so there does seem to be some trend in longevity/quality (or maybe it's just the memory that's losing its quality )

 

[ERD50]

My current water heater is ~ 25 yo, so you might just need a simple fix, like readjusting the thermocouple, or a new thermocouple - these are just a few bucks and easy to replace. I think they tend to burn down after many years, and then the pilot flame doesn't get them hot enough for them to keep the gas valve open - this is likely why the pilot is going out.

But I think you may have a dangerous condition, so pls check this out.

With all the standard pilot light systems on furnaces and water heaters that I have seen, the thermocouple is heated by the pilot, and that thermocouple generates enough current to keep a valve open - this is the fail-safe. If the thermocouple is cold/damaged, the main gas valve closes. This is why you need to hold that pilot button for a minute - that gives the thermocouple time to warm up and generate a holding current. The thermocouple doesn't have enough power to pull the valve open, it can only hold it open once it is opened manually (by you pressing the pilot button).

Maybe that fail-safe valve is stuck open? Maybe there is some gas leaking somewhere to cause the flash? Maybe the pilot is low, and the larger flame blows it out?

On my furnace, I've had the draft inducer motor pull the pilot flame away from the the thermocouple enough that it would shut down after a few minutes. I moved that little hood on the pilot to direct the flame closer to the thermocouple, and all was well. Does your water heater have a draft inducer?

Probably a simple fix though.

edit/add - I keep a spare thermocouple at home - this is exactly the thing that can save you an expensive service call, or waiting for the HW store to open.

-ERD50

 

[FIRE'd@51]

But I think you may have a dangerous condition, so pls check this out.

I don't know how it is where you live, but when I lived in NY and had natural gas, the gas company was required to come out and check for a gas leak for free within 24 hours. You might want to give your utility that provides the gas a call and see if they will check it for you.

 

[pb4uski]

It sounds to me like it would be safer to have it checked out by a qualified technician. It could be something simple or could be more serious. Why take the chance for a couple hundred bucks (or less).

 

[rbmrtn]

As was mentioned the thermocouple does have to warm up for it to work properly. I know when I start the gas logs after being off, I have to hold it on for while for the pilot to warm up the thermocouple.

Another issue is dirty/clogged pilot or burner. What color is the flame when lit ? it should be a bright blue.

 

[Tyro]

My current water heater is ~ 25 yo, so you might just need a simple fix, like readjusting the thermocouple, or a new thermocouple - these are just a few bucks and easy to replace. I think they tend to burn down after many years, and then the pilot flame doesn't get them hot enough for them to keep the gas valve open - this is likely why the pilot is going out.

+1. I'd investigate this first as most likely & least expensive. If it doesn't work, I'd call in the pro.

Tyro

 

[ERhoosier]

I actually couldn't get a gas-fired water heater with a 9 year warranty last time our water heater went... the only option any of the stores or plumbers I checked with would offer was a 6 year warranty. Crap gets crappier.

Ain't that the truth

 

[Dimsumkid]

I actually couldn't get a gas-fired water heater with a 9 year warranty last time our water heater went... the only option any of the stores or plumbers I checked with would offer was a 6 year warranty. Crap gets crappier.

I was able to find 3 natural gas units w/12 yr warranties on them available now at Home Depot.

Residential Gas - Water Heaters - Plumbing*at The Home Depot

 

[Mulligan]

It sounds to me like it would be safer to have it checked out by a qualified technician. It could be something simple or could be more serious. Why take the chance for a couple hundred bucks (or less).

I will agree with you PB. I have a natural water heater that is going on its 10th year and I haven't touched it. I don't understand how the
natural gas systems work. I am afraid I will do something that will cause an explosion. When I had electrical ones, I would replace the elements and such, but I won't go near this one.

 

[zinger1457]

I had to replace the thermocouple on my 12 year old LP water heater recently. It is a common failure component on water heaters. It's also a simple and cheap DIY job, can pick one up at any of the big box stores.

 

[kaneohe]

Thanks and much appreciation for all the inputs. Compiled all the inputs and decided to get a new one......figured I got my $$ worth of the old one w/ probably lesser quality than in the good ole days + concern about possible safety problems. In my younger/fitter/and penniless days I might have attempted the TC fix but after spending many minutes just trying to put the old inner door back in properly several times, I know that the real world has more obstacles than can be imagined......esp. w/ some difficulty (hopefully temporary) doing things requiring pinch grips w/ right hand in small spaces.
New one has only 6 yr wty but supposedly is greener so hopefully will save some $$ monthly.

One lesson learned.........was supposed to get a $30 Yelp discount but you can't know whether or not you got it unless you clarify first whether the quoted
price is before or after the discount.

 

[Dimsumkid]

I'm wondering if anyone has ever tried to use the warranty claim on a water heater. I read mine yrs ago, and I believe it's prorated based on years left on the coverage on the part only, you still have to pay the labor costs...just like a car battery. Can anyone share their story if you've done this?

 

[ERD50]

New one has only 6 yr wty but supposedly is greener so hopefully will save some $$ monthly.

The 'greener' thing would be to fix the old one.

-ERD50

 

[JoeWras]

When you are away and gas isn't moving through the burners, spiders sometimes move in. This could have caused the flash and pop.

Spiders are a very common problem on outdoor gas grills.

 

[kaneohe]

I'm wondering if anyone has ever tried to use the warranty claim on a water heater. I read mine yrs ago, and I believe it's prorated based on years left on the coverage on the part only, you still have to pay the labor costs...just like a car battery. Can anyone share their story if you've done this?

Haven't tried to claim wty benefits but new one reads:
1 yr P&L
6 yr H2O heater

Not sure exactly what that means but almost sounds like any part replaced costs after a yr. Maybe that leaves only the tank itself for 6 yrs?

 

[ERD50]

When you are away and gas isn't moving through the burners, spiders sometimes move in. This could have caused the flash and pop.

Spiders are a very common problem on outdoor gas grills.

Good call. That could be it.


-ERD50

 

[bUU]

I was able to find 3 natural gas units w/12 yr warranties on them available now at Home Depot.

Residential Gas - Water Heaters - Plumbing*at The Home Depot

So was I - none of them were available when I needed to get one. My plumber promised to find one, and couldn't.

 

[Tyro]

When you are away and gas isn't moving through the burners, spiders sometimes move in. This could have caused the flash and pop.

The first time or two, sure. But after that, wouldn't the spider/web have burnt out?