Water Heater Thermocouple Problem

[Slither]

I live in a double wide manufactured home w/ outdoor water heater closet.
Water Heater is a Kenmore Economizer 6 and was installed I believe in 2006 when my old water heater went bad. Natural gas, not propane.

The pilot went out and the symptom was classic bad thermocouple - after lighting, it would go out as soon as I let go of the knob from light pilot position.

I replaced it with a Honeywell "universal" and the pilot would then stay lit and light the boiler plate. It seems to work, but if wait 20 to 30 minutes and check, it is out again.

After lighting I can hear sizzles that sound like drops of water hitting the boiler plate, but I think that is just the water heater sweating, because it is dry in their when the pilot has gone off and boiler isn't lit.

Anyone know what the issue might be, why it doesn't stay lit for more than half an hour?

[paul52446m]

I live in a double wide manufactured home w/ outdoor water heater closet.
Water Heater is a Kenmore Economizer 6 and was installed I believe in 2006 when my old water heater went bad. Natural gas, not propane.

The pilot went out and the symptom was classic bad thermocouple - after lighting, it would go out as soon as I let go of the knob from light pilot position.

I replaced it with a Honeywell "universal" and the pilot would then stay lit and light the boiler plate. It seems to work, but if wait 20 to 30 minutes and check, it is out again.

After lighting I can hear sizzles that sound like drops of water hitting the boiler plate, but I think that is just the water heater sweating, because it is dry in their when the pilot has gone off and boiler isn't lit.

Anyone know what the issue might be, why it doesn't stay lit for more than half an hour?

Things that make pilots go out. Dirty pilot burner, Dirty main burner, popping on hard or popping off hard.. Too hard of up draft
or too hard of down draft. Magnet in gas valve getting weak. Even new thermocouple couples can be bad. Thermocouple not into pilot flame enough, flame should go around the thermocouple end about 1/2". Leak in tank leaking water on pilot. Later Paul

[Redwood]

Oh Boy...
First off Kenmore does not make their own water heaters they are made by someone else and labeled.

I believe though I'm not 100% sure, that your Kenmore is actually a FlameGuard Water Heater which was made by American Water Heaters, State, Reliance, or AO Smith (all the same company now). These water heaters have a flame arrestor on the bottom that becomes clogged with dust and lint as one would expect with it being on the bottom...

When this becomes clogged the pilot flame starved for air becomes higher and overheats the thermo couple which on older models was a one time thermal fuse. This design resulted in numerous complaints and a class action lawsuit which resulted in owners being sent a new burner assembly which had to be installed. I question the wisdom of telling homeowners to do this level of repair on a water heater but they got away with it.

You need to call 800-659-7026 to find out what you have and whether your water heater is before or after the burner enhancement kit design wise.

Here is a link with more information.

Even the newer "Fixed" models have been problematic and drive their owners crazy trying to keep them running. They now say to clean the flame arrestor on the bottom every 3 months.

Really the only relief some owners get is when they finally rip the junk out and install a new Bradford White or Lochinvar water heater in its place which have a much better design on the flammable vapor ignition resistant system...

Rheem/Ruud and GE also have a 1/2 decent design which I'd put in second place...

[Slither]

This morning it is still lit, and no popping sound. Hopefully it is just a matter of it was sweating while initial heating taking place with occasional drop of water landing on the pilot or something. I guess time will tell.

[Slither]

It's official. I'm an idiot

It went out again, so I started to remove it to try another.
Where it screws into the thermostat - I neglected to tighten it. Tightened it and so far as been flawless.

Maybe that wasn't it but I suspect it was.

[HayZee518]

the thermocouple is a bi-metal device that generates a millivolt signal [voltage] it consists of an insulated wire inside the copper cappillary. at the heat sense area it is welded to the inside of the tube. it is here that it forms a junction of dissimalr metals. typically it is called a j-k thermocouple. the other end of the wire is connected to the silver button at that end of the cappillary. when it is screwed into the main valve the button makes contact with the sensitive electromagnet in the pilot valve. the other side of the magnet wire is grounded to the valve case. the two thin nuts hold the thermocouple in place in the flame.

[Slither]

the other end of the wire is connected to the silver button at that end of the cappillary. when it is screwed into the main valve

That's the part that I didn't tighten. Seems to be working just fine but until it is working for 48 hours I'm going to keep checking every few.

[Redwood]

Did you clean off the flame arrestor on the bottom of the unit?

I would highly recommend doing so...

[Slither]

No I didn't. So far it is still lit, so I'm not going to further mess with it unless it goes out.