Lighting water heater pilot light (shouldn't it stink?)

Had to fix a Kenmore 50gallon gas water heater whose outlet hose was leaking at the top.

Then tried to relight the water heater, but failed to light the pilot. Spent more than an hour on it.

Held that button down for so long my fingers hurt as I pressed the green sparker.

Could see spark, but no flame ever. Never did smell gas. All valves are open as far as I can tell (PG&E feed).

Shouldn't holding the pilot button down for minutes on end result in the smell of gas?

(I have pictures but that's the technical detail.)

Reply to
Danny D.
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Reply to
Paul

Sounds like a bad gas valve? I'd take the burner assembly out and clean the pilot, but sounds like it was working before, so that's probably not the problem. You could also disconnect the pilot line at the valve, hold the button and see if you detect gas coming out.

Reply to
trader_4

yes, did you turn a gas valve off someplace and forget?

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Reply to
makolber

Thanks for the video. I actually know all that stuff but that wasn't the question! :)

But I still appreciate the help.

Here's all that stuff I did, so we don't rehash it over again:

  1. You test the safety valve (by flipping the hinge at the top)
  2. You flush the water tank (by putting a hose on the bottom)
  3. You replace the sacraficial anode (this one was easy, most are hard)
  4. You replace the upper two pipes (the rubber & plastic gaskets wear) (I did all the above first.)

This is the procedure I was following: a. You turn on the gas (that's part of the problem, maybe) b. You turn the large temperature knob to pilot (clockwise till it stops) c. You twist the pilot button to pilot & press (it will hurt after a while) d. You snap the piezoelectric sparker (you can see the spark in the glass) e. ------ at that point is where nothing was working ------- f. If you're lucky, the pilot flame will actually light g. You keep the pilot button down for a minute to warm the thermocouple h. Then you lift up on the pilot button & turn to the on position i. You hope the flame remains (otherwise heat up the thermocouple more) j. If flame remains, you turn the temperature knob to A, B, or C. k. Then you put the filter screens back on the bottom l. And you screw the pilot light plate back on m. And you clip back on the protective covering on the mechanism

My main question is in the subject line, which is that I couldn't light the pilot, but I also didn't ever smell gas. Shouldn't holding down the pilot button eventually reveal the smell of gas?

Another question I have is what folks think of this sacrificial anode?

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The heater was built in October 2007, so I probably put it in around then:

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That sacrificial anode is gone on the top and bottom but not the middle:

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Anyone have experience with whether it's "gone" or if it still has "time"?

Reply to
Danny D.

I too would have thought that I'd smell gas if I hold down the pilot button and if I did all the other stuff (which I did).

a. Turn on both gas valves b. Turn the temperature dial to the pilot position (clockwise stop) c. Press the pilot button for minutes on end

Anyway, it finally lit this morning, so, it's fine now. I never did smell gas though.

Also, the sacrificial anode looks like this.

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When I put it back, I wasn't sure if we're supposed to PTFE tape it.

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Are we supposed to PTFE tape the sacrificial anode rod threads?

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Reply to
Danny D.

Hi Oren,

Thanks for letting me know that the same thing happened to you, which is that the pilot wouldn't light after the two valves (see below) had been shut off for a couple of days.

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It finally lit this morning, so you must be right that the gas line loses pressure (or that the wetness from all the water prevents the pilot from lighting).

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I never did smell gas though, so, mainly the question is whether we "should" smell gas if we hold down the pilot light forever.

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This is what the garage looks like.

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It's not too bad with respect to flammables.

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Reply to
Danny D.

Hi Trader, You are correct in that it was working fine until this weekend.

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The boyfriend of my sister turned off the gas.

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He also shut the water valve coming into the hotwater heater.

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All I did was replace an outlet pipe.

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That 12-inch male:female pipe is incredibly impossible to find!

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I drove to Lowes, Home Depot, Ace, OSH, and to two plumbing supply stores! Nobody had it.

They all had plenty of Rube Goldberg solutions, so, I ended up putting in a copper pipe with a brass nipple.

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They told me you can't connect copper to galvanized, so, I had to put that brass nipple in the middle.

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They said you can connect brass to galvanized, and copper to brass, but not copper to galvanized.

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Is all that true? This is my sister's house, where we finally moved her back in! (Long story for another time - but the net result is hooray!).

She's been there a month now, and she didn't tell me that the hotwater heater was leaking out the exit pipe.

Reply to
Danny D.

Maybe not if there is a strong enough draft there without it being lit. In that case, the pilot gas goes up the flue.

I think there was plenty still left there and no need to replace. Also, there are two theories on replacing these. One is that it will significantly extend the life of the tank. the other is that the anode is sufficient to solve that part of the problem for most water conditions, ie that when the anode is about gone, the heater is probably at the point where other failure modes unrelated to the anode kill it anyway.

It's still working as long as there is metal there and it's connected to the tank. Yours looks like most of the metal is still there. If it was down to 1/4 size or less, then I'd replace it.

Reply to
trader_4

I guess that might be the case. This is in a garage. The door was open. There wasn't any wind, but, maybe there was just enough of a draft to wisp the pilot gas away.

Thanks. I see that there is about half left, but I have no experience since the last one I tried to get out wouldn't budge.

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Luckily, this one came out with the plumbers tools shown below:

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I'm not sure what that tool is called, but there was no way I was gonna get that sacrificial anode out using a screwdriver in the "handy hole" they provide for that purpose! I had to use the pipe wrench for leverage!

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I ended up using the pipe wrench, which, surprisingly, didn't collapse the thin cheap metal on that plumber's socket.

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Surprisingly, the plumbers socket was just thin-walled enough to fit over the sacrificial anode hex head:

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Here is the anode against the tank, showing it goes in most of the way:

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This tank I put in for my sister so looking at the date, it was made in October 2007, and it's a Kenmore, so, I probably bought it from OSH (which was nearby). So that makes it, at most, 9 years old.

I see the math you are saying, which is that the anode is about halfway gone, based on these pictures:

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If that means the anode will be completely gone in, say, 5 more years, then, that's just about the life of the tank itself anyway.

Yikes! Connected to the tank? Oh oh ... I think that's why there was no PTFE tape on that anode! I put TPFE tape on. That's probably stupid of me!

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Why don't you tell me these things before I do them!!!!!! (jk).

I think I have to go back now, and remove that TPFE tape! Do you agree?

Reply to
Danny D.

Forgot to add in that last post, you're trying to light it with a pushbutton lighter on the tank? Can you get one of those butane lighters in there and try using that? Could be the spark gap is slightly off from where it needs to be or something.

I guess it depends on whether the threads cut through the tape at some point to make contact or not. If it's insulated, it won't work.

Reply to
trader_4

Exactly. If the gas line has been open to the air, it takes a long time to use up all that air through the pilot valve before the gas actually gets there.

Reply to
Pat

That's a good idea!

It's not my house (it's my sister's place) so I will go back there and bring an ohm meter and the wrenches.

If it ohms out well, then I'll leave it (as the anode is fragile as it is and had to be bent to get it out near the end). Otherwise, I'll spin it out and remove the TPFE tape.

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Now I know why you want a LOT of room above a hotwater tank when you're designing where to put them! That thing is almost as long as the tank itself!

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It corroded only at the top end:

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And at the bottom end:

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But not in the middle:

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Anyone know why it doesn't corrode in the middle?

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Reply to
Danny D.

I was a little worried about the visible white plastic on the copper pipe, especially since the older rubber-encased-by-mesh pipe clearly leaked (there was black mush when I removed it, presumably from rubber components). Presumably the hot pipe "cooks" non-metallic bushings.

Reply to
Danny D.

I guess that explains everything, in that it explains why I never smelled gas and why it wouldn't light for the hour that I tried and why it finally lit in the morning.

However, there must have been gas pressure coming from the main source so, the only distance the gas had to move was the last foot.

Does it really take a long time for the gas to move one foot? What's the pressure in those lines anyway?

Reply to
Danny D.

It's not designed to get a lighter in there.

So removing the metal holding the wires and tubes was going to be my avenue of last resort since a nutdriver would remove the plate that holds the pipes that go into the bottom:

  1. Thin aluminum pipe for the pilot gas
  2. Thin copper pipe for the thermocouple probe
  3. Thin orange wire for the piezoelectric snapper
  4. Thick aluminum pipe for the main gas

It's all lit now, but I guess one of three problems happened: a. Maybe it was too damp from all the water to light? b. Maybe there was just enough draft from the garage being open? c. Maybe the gas pressure needed to slowly build up?

What's odd is that I never smelled gas.

I just realized I probably should have used that gray never seize paste because that conducts electricity (I guess) but then I'd have to worry about contaminating the water.

I guess that's why the original sacrificial anode threads had nothing on them that I could see. They certainly were in tight, so, I guess I didn't need the TPFE anyway.

Reply to
Danny D.

This is the best answer since I didn't think being damp would make that much of a difference, nor was there any wind and certainly the gas valves were in the on (parallel) position.

The fact I couldn't smell the gas is an indication that I was just getting air. It seems that leaving it on for a while will mix the air and gas at a

50% ratio (more complex than that due to vapor pressure calculations - so I just say 50% but the ratio will depend on vapor pressures for each gas, I think).

Nitrogen 78% Oxygen 21%

Reply to
Danny D.

Good idea. That's what I love about this newsgroup. Each time I do a repair, I find out what I did wrong!

Reply to
Danny D.

Why didn't you use galvanized steel pipe? Better than those flex fittings. Cheaper too. You don't even need a cutter/threader for that job, as they sell the nipples you'd need. As far as gas smell, newer burners are hermetically sealed. Even so, when my basement flooded I broke the glass out so I could dry the burner out. Didn't know if the piezo sparker would still work, but it turns out it was okay. Even with the glass port open, I didn't smell gas. Other have offered explanations of why that is, but I'll add another. Could be your smelling is weak - very little gas comes from the pilot, and it's sealed off. My wife smells gas before I do.

Reply to
Vic Smith

The hard part, I guess, is "purging" a gas line, without disconnecting it and sucking on one end.

Reply to
Danny D.

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