Plumber in the house??? Pilot light won't stay lit on WH...

[Sweetpea]

Gas supply seems to be fine...

Anything else to check?

The WH is only about 2.5 years old.

Brandon

[Pb2au]

Check for a build up soot around the orifice where the flame emanates. It may be causing the issue.

[farmerjim]

The Thermocouple is probably bad.

[longranger]

Second the thermocouple. HW heater should still be under warranty no ?

[BBQJOE]

Does the pilot light burn? If not, try heating the thermocouple with a match or torch in the pilot position. Then turn it to on. If the burner lights, it's not the thermocouple.
I have seen where the gas feed to the thermocouple sometimes seems to plug up with some junk that can't be poked out.

[Sprue]

...had the same issues a while back. I found a brass brush that resembles a toothbrush. I then taped it onto a wood dowel rod to lengthen it. Gently run the brush all around the igniter & thermocouple. If you take a strong flashlight and look in that area, you will probably see a "white" buildup of deposits. Mine has worked ever since.

Good Luck

[mroliver77]

I thought all new gas appliances were electronic ignition. No standing pilot.
J

[Zymurgy50]

Clean the thermocouple of any soot and then inspect it. If it appears to be melted or burned through in any spot, replace it. Ensure that the coil does not touch any metal part between the tip and the threaded base.
Thermocouples generate a small electric current when heated, that electric current hold open the gas solenoid valve.

While you are at it, drain about 5 gallons of water from the drain valve on the heater.

[roscottjr]

Replace the thermocouple, cost is around $7 or less. Even if your thermocouple looks fine, still replace it. 99% ot the time this is the issue.

Robert

[Sweetpea]

OK...

So I found a new thermocouple, newer style with 2 wires, cost $28 something.

Hooked it up, and no dice.

There is flame when you light the pilot, but the pilot will not stay lit.

I really would like a warm shower today...

[Phoenix]

I thought all new gas appliances were electronic ignition. No standing pilot.
J

All my gas appliances are less than 2 years old and they all have pilots, brand new Bosch tankless hot water heater brand new range from Ge

[Phoenix]

If the flame from the pilot is hitting the thermocouple and you change the thermocouple then the only other thing it can be if it won't stay lit is the control valve.

If the flame is not hitting the thermocouple then your problem is probably related to the flame not being big enough or strong enough to reach it. Clean the air inlet most of the time there's a small screen around it can get plugged with dust usually just some compressed air is enough to solve the problem

[daniel lawecki]

Is it a Whirlpool pre bent thermocouple because the price of the part tells me so pm me.

[turmech]

Look for a reset button. Many newer water heaters have have them. In the pic it is to the right and white in color. In the center is a push button. Most of the time there is a slight audible click or you feel it click. You also should have continuity through the switch with the wires off if you have a ohm meter.

If that is the problem you need to check the flame of the main burner and make sure it is flowing up and out of the water heater. If it is rolling out sideways you have a problem in the venting.

You may want to move the water heaters temp setting as some times they stick and overheat the switch. If all that is OK the switches do go bad.

[MT Gianni]

The flame should envelope the thermocouple, as in surround the top 1/3-1/4 of it. The flame should be near blue and not soft and waveing like a candle flame. If the flame does not make sure that the t-couple is pushed in all the way forward. The quickest fix for a dirty pilot is to tap the pilot assembly with the end of a screwdriver. If there is a porcelain ignitor do not hit that. make sure the gas is flowing through the pilot when you do this by holding the pilot valve in so it carries away any dust or crud. I have not seen a 2 wire system on a WH but have been out of the service end for a few years. A screw in t/couple has a millivolt raring of 30 mv and 12-15 should be enough to hold the pilot safety in. A quick check with a volt meter will confirm this. Gas valves do go bad but it is rare. WH warranties were 5 yrs on tank and one year on the components for a long time. That leaves you out of luck @ 2.5 years.
If you have a barbeque lighter heat the thermocouple tip as the pilot is lit for no more than 30 seconds and check to see if it stays lit. If it does there is not enough heat to keep things lit. If not it is probably a valve issue with a new thermocouple. There may be a red reset button on a rollout switch. If there is too much heat that would indicate a venting failure and the system would lock out. Some are manually resetable others are a one time use. All of these components and connections eat voltage and you have only 30/1000 of a volt to work with. In the good old days a gas valve was 50% of the cost of a WH. I have no idea what they run now. In either case to drain the WH, replace the valve and check the system ran about 1 hr labor or almost the same as replacing the heater. AS a young hot shot if you were lucky you could stab a new one while the water was still on while pulling the old one with out loosing over a gallon of water if the shut off valves were shot. A 2 1/2 yr old WH might be new enough to take the risk of replacing it.
I am sending you my phone # by PM if I can help. Good luck with it.

[Petrol & Powder]

Second the thermocouple. HW heater should still be under warranty no ?

+ 3 or more on the bad thermocouple

[jmort]

The valve on mine won't stay rotated in right place, so I had to duct-tape it into place. Just fully rotated it and applied the tape. Definite Beer Can Engineering.

[Sweetpea]

So I pulled the burner out, and cleaned up around the pilot. Not that I saw anything there to begin with.

As far as the reset button, I wasn't sure just what it was, and I even bypassed it, thinking it may be the problem.

Still no dice. I am guessing that the valve is bad.

Frustrating...

Off to have a cold shower... at least I live in the desert!

Brandon

[jmort]

Try taping it in place, I had same problem, pilot light would go on in start-up pilot light position and then it would go off when rotated into final spot. Discovered that it it was backing off, so I fully rotated into place and duct taped it into place.

[mroliver77]

All my gas appliances are less than 2 years old and they all have pilots, brand new Bosch tankless hot water heater brand new range from Ge
I have been away from working on them for a few years but everything new we installed had igniter bars and no standing pilot. I thought the feds had outlawed standing pilots on new appliances. Thanks for the information.
J

[frkelly74]

I had a brand new LP waterheater that would not stay lit. It was a newfangled type i had never seen before that used the flame to generate a current much the same as a thermocouple but there was a diode that was supposed to blink a certain way when you were to release the button. No blink= no light. I ended up calling the 800 number and the tech told me that once in a while there would be a bad connection at where the terminals for the thermocouple like device was hooked up, and I was to unplug both of them and plug them back in and wiggle them around a little. It worked. there is such a small current that any resistance kills the circuit. The people on the 800 number were very helpful.

[powderburnerr]

are you holding down the pilot valve plunger for about 30 seconds before letting up on it? it has to heat the thermocouple before it will hold the valve open,

[Sweetpea]

Yes, I held the pilot in until it blinked properly.

The light then blinks to say that the pilot is working properly.

I'm guessing the valve is the issue.

[MT Gianni]

I have been away from working on them for a few years but everything new we installed had igniter bars and no standing pilot. I thought the feds had outlawed standing pilots on new appliances. Thanks for the information.
J

Water heaters were given an exception as the pilot heats the water.

[Pepe Ray]

Yes, the thermocouple COULD be bad.
BUT
If carbon,dirt, dust,animal hairs, anything to interfere with the flame which needs to heat the thermocouple.
is present then a good cleaning is needed.
Try the simple stuff first.
Pepe Ray

[Sweetpea]

I had the service guys over today.

It was the valve, under warranty for the part, but I had to pay $145 for the labor...

Still cheaper than a new WH!!!

Brandon

[retread]

I had the same problem when living in Winnemucca. Windy place. When the wind shifted to the SE and was gusting a little my pilot light would go out. I went up on the roof and put a deflector on that side of the vent and that solved the problem. Vent was on the south side the pitch of the roof protected it from the north.

[ballistim]

Sounds like it could possibly be the control valve from what you've described. Is it a Honeywell valve? I used to repair water heaters daily, and most pilot outages are caused by a defective thermocouple or dirty pilot, (about 3/8" of flame should touch t-couple), weak magnet in control valve, or venting/air adjustment or plugged intake screen as previously mentioned. Was your fuel line pressure checked? Pressure can be a problem that is often missed. Some manufacturers install safeties that will not allow relighting until repairs are made. I even recall a manufacturer installing a bulb-device that would break to indicate a venting problem, and the only option was to replace the tank! Good luck with the repair, curious to see what cures the problem.

[ballistim]

I have been away from working on them for a few years but everything new we installed had igniter bars and no standing pilot. I thought the feds had outlawed standing pilots on new appliances. Thanks for the information.
J

Water heaters with sealed burner doors and intake air screens with push-button ignition using standing pilots were used to replace the older style of standing pilot water heaters. OP stated 2-wire t-couple, don't know enough about current units to know if there is a separate flame sensor like in hot surface ignition applications or if t-couple is only pilot safety. Older style t-couples could be checked with a special adapter to connect in-line with the t-couple to read voltage in millivolts. A quick check of a suspected problem with pilot outage where the pilot stays lit but goes out again is to time how it takes for the magnet in the control valve for the pilot gas to drop out. A good t-couple/control vlv combo should allow for at least 45 seconds from the time the pilot is blown out until the magnet in the valve drops. Sometimes you can hear the magnet drop, other times placing a finger on top of the control valve allows you to feel the magnet drop. Hope this helps someone in the future if they have pilot light problems with water heaters or older furnaces.

[turmech]

His has a thermogenerator by what he is describing with the blinking light and two wires coming off the thermogenerator (red and white). Sounds like a Bradford White, but the I have been told (can't say for certain but it is believable) most all water heater are made by two different manufactures and then sold under various names. American Water Heater Company make a lot of the ones I see around hear anyway.

[ballistim]

His has a thermogenerator by what he is describing with the blinking light and two wires coming off the thermogenerator (red and white). Sounds like a Bradford White, but the I have been told (can't say for certain but it is believable) most all water heater are made by two different manufactures and then sold under various names. American Water Heater Company make a lot of the ones I see around hear anyway.


I've heard the same regarding only a few manufactures with different name brands, and I know it's true with other appliances. I know about thermopiles going back to the old gravity furnaces and have worked on gas logs that still use them but have been out of it long enough not to know about using them in water heaters. I remember all the long days and nights in the big city checking millivolts, for sure! I remember guys not wanting to replace the pilots using D cell batteries to get out the door, and some of them lasted quite a while!

[MT Gianni]

I even recall a manufacturer installing a bulb-device that would break to indicate a venting problem, and the only option was to replace the tank! Good luck with the repair, curious to see what cures the problem.
ECO or Energy Cut Off device since the 60's opened the circuit if the temps at the control valve reached 200 F. Along with the relief valve this prevented a steam explosion.

[ballistim]

The ECO is different than what I mentioned, am familiar with those and they have been around for a long time as you've stated, and PT valves are for pressure as you've also pointed out. I was referring to the FVIR water heaters with sealed burners like a Rheem where if the glass vial breaks the tank needs to be replaced.