Causes of quick failure of igniter

jkn

A.O. Smith GDHE-50 125 LP hot water heater has burned out 3 igniters in 4 weeks. The first was no surprise. The 2nd and 3rd lasted 2 weeks each. I'm being careful during installation, not touching it, no bumping. Is there a known high incidence of faulty replacement parts for this? Or is there something else I should check for an underlying problem to lead to premature failure?

Larry Weingarten

Hello, I can't tell by looking online. Is this a hot surface igniter, or a spark igniter? Hot surface igniters are quite delicate. Can you tell us anything about the failure mode? What does it do, or what do you find? How is the appearance of the failed unit different from the new one?

Yours, Larry

jkn

hot surface. I can't see an obvious crack, but ohmeter shows infinite resistance between the leads. The actual error on the water heater display is that the igniter amperage is too low (indicating low or no current flow).

Larry Weingarten

Hi, just to eliminate other possibilities, can you ohm the igniter directly at the igniter itself? If there were a bad connection at the leads, it could confuse locating the fault. I use an old analog meter, so I'd put it in the ohms times 1000 range and see if there is any continuity at all. A question, is there any way condensation could fall onto the igniter? That could really mess things up! Also, is there any possibility of a short to ground anywhere along the current path?

Yours, Larry

jkn

In case anyone has a similar problem, I think I found the issue. The exhaust pipe was clogged with accumulated residue from the exhaust gases. The exhaust sensor had been bypassed. I'm guessing the burn chamber had excess humidity, and who knows what else that was improper conditions, causing the igniter to fail prematurely. Apparently the clog had only recently become nearly complete.