Thanks in advance for reading this and helping me out a bit, as I am not sure if our water boiler needs to be replaced.

We have a AO Smith natural gas water heater that is about 14 years old. During the past couple of months, we noticed that the pilot light would go out approximately every two days. Thinking it may have been a thermocouple issue, I took out the burner assembly and replaced the thermocouple about a month ago, during which I noticed that the burner assembly was wet. However, the pilot light continued to go out after about two days after turning it on.

Just today, I took out the burner assembly again in an attempt to replace the thermocouple, and again noticed that the burner assembly was wet and rusted. I then noticed that the top of the burner chamber next to the vent hole was wet. Over the course of the day, the wet area slowly got larger.

Note that the pilot light went off at midnight the day before so it was about early afternoon the next day when I took these photos.

Do I have a leak here, or is it a condensate issue?

Here is the burner assembly when I took it out. Burner assembly

Burner assembly

Here is a picture of the top of the burner chamber. Top of burner chamber

  • 1
    Condensation tends to happen on cold surfaces in humid environments. I'd be a bit surprised if a water heater ever became cold enough to cause that under normal circumstances.
    – keshlam
    Oct 13, 2023 at 23:31
  • 1
    Leak. Replace this heater ASAP before it fails catastrophically and causes a lot of damage. The service life of a standard gas fired tank water heater is highly variable, but 14 years is plenty of life out of one of these. Oct 13, 2023 at 23:44
  • I got 20+ years out of mine. Swapped it out because we noticed it was leaning - one leg had rusted to complete failure.
    – FreeMan
    Oct 14, 2023 at 1:35
  • Well, one of the byproducts of NG combustion is water...
    – Huesmann
    Oct 14, 2023 at 13:33

1 Answer 1


The picture of the top of the chamber appears to show that condensate in the flue would drip off the inner pipe, which projects slightly below the bottom shell, so water appearing outside that has got to be a leak.

Also, the pipe itself appears to be dry from that picture. Which again suggests a leak.

And more than 12 hours after the pilot went out, any condensation in the flue should have long-since been dried.

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