Water heater flameout: cleaning the electrode

My five-year-old Suburban water heater started to act up: it would light, and then go out, and relight, and go out, several times, until it would finally start to burn steadily. I did the usual Google research and discovered that this is fairly common on home water heaters, when deposits build up on the ignition electrode.

Surprisingly, I couldn't find any "how to" postings on this site (or anything specifically about cleaning RV water heater electrodes), so I decided to document the process. (If I'm repeating something that's in the archive, please forgive me.)

The first thing is to remove the shroud or cover over the burner assembly. On my water heater, the shroud was attached with three screws. This is the center screw:

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This is the right side screw (which was kind of hard to see):

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And this is the left side screw:

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Once the shroud is off, the burner assembly with the electrode is very easy to see. In this picture, I have already removed the burner. Frankly, I don't think it was necessary to do so, but I wanted to make sure that I would not damage the electrode when removing it:

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I then slid back the orange rubber end-cap to gain access to the screw. I unscrewed the single screw holding the electrode in place (use a quarter inch socket or wrench). Finally, I rotated the electrode by 90 degrees to extricate it carefully from the bracket:

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When I pulled out the electrode, I could see a grayish powdery deposit on the tips and the sides of the electrode. This picture does not show the deposits very clearly:

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I then took a small piece of 100 grit sandpaper and gently scuffed away the deposits on the metal prongs:

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Reinstalling the entire thing was pretty simple - just reverse the steps.

Problem solved -- it works fine now.

17 Replies

TurnThePage
Explorer
Feb 28, 2018
I found this to be an informative post.

Thanks to profdant139 and other contributors!
profdant139
Explorer II
Feb 28, 2018
CaFord, you sound like you know what you are talking about. It would be pretty funny if I fixed it by accident -- sort of like jiggling the handle on the toilet and hoping for the best!

Oh, well -- I had fun with the sandpaper, anyways.

(Actually, I really did look at several YouTube videos where plumbers used sandpaper on home water heater electrodes, so my experiment is not as random as it seems. But maybe the plumbers were benefitting from the same accidental fix as I did??)
RJsfishin
Explorer
Feb 28, 2018
If your problem really is fixed, I don't believe cleaning the electrodes fixed it either. More likely the contact connections did.
Those thermocouplers are not very expensive,.....to carry an extra.
CaFordGuy
Explorer
Feb 28, 2018
I believe the problem is a high resistance connection on the ground side of the electrode. The heater uses the change of resistance across the electrode when the flame is present to detect a lit flame. It's looking for a micro amp level current so good connects are important. If it doesn't detect this it shuts down the gas and then tries again. Hence the cycling. It appears that once the temp rises due to the cycling the current is large enough to be detected.

While it is good to have clean electrodes, I believe that you fixed the problem by unmounting / mounting the electrode from the frame of the heater. I had this problem and a through cleaning of all ground connections seemed to have fixed the issue.
profdant139
Explorer II
Feb 25, 2018
Nope. Clear as a bell in the tube and the burner. Pretty sure this was an electrode problem -- the symptom was intermittent ignition during the first few minutes of use, followed by good performance. An air supply problem would probably not clear up during usage.
SDcampowneroper
Explorer
Feb 25, 2018
profdant139 wrote:
SDcamper, we found that this was happening even at sea level, so I ruled out the air supply issue. But if this re-occurs, I will have to play around with the intake.
OK, ? suspect restriction in the heat exchanger tube, like a mud dobber nest. That would cause a backpressure air flow that would cause the flame to blow back until the tube is heated enough to create draft. ?
profdant139
Explorer II
Feb 24, 2018
SDcamper, we found that this was happening even at sea level, so I ruled out the air supply issue. But if this re-occurs, I will have to play around with the intake.
ScottG
Nomad
Feb 24, 2018
Ava wrote:
I have an Atwood water heater and do this as part of my annual maintenance. I do the same for my fridge igniter.

That's a good idea. Going to make that part of my dewinterizing routine!
SDcampowneroper
Explorer
Feb 24, 2018
Flame out is often an altitude associated problem. At high altitude the flame can be lazy, sooty and quiet due to insuffiecient air, so adjusting the air tube open allows for correct air with the propane orifice.
In low altitudes, overly open air inlet to burner tubes can cause a too lean burner giving a roaring, jet engine sound to the flame.
In case of flame out with the burner air supply correctly adjusted for the altitude, then the culprit is burner fan supply. ( high or low barometric pressure)
Try restricting burner fan supply air with a finger or 2 until flame is quiet, lights on the burner every time. Then block that amount of burner air intake with a bit of electrical tape. At very high altitude propane pressure may have to be reduced.
Ava
Explorer
Feb 24, 2018
I have an Atwood water heater and do this as part of my annual maintenance. I do the same for my fridge igniter.