Water heater burner won't stay lit

Question

I'm having trouble keeping my water heater burner lit or lighting automatically.

• When I press the pilot reset button (allows a small flow to generate the pilot light) and use the piezo sparker, it lights fine. Hold for about a minute and it stays on (my guess is that this warms the TC so the gas doesn't shut off), as it should.
• When I release the pilot button and turn the knob from pilot to on, allowing a normal gas flow rate, I usually hear a quick burst of gas and then it immediately shuts off.
• If I finesse it and turn the knob very slowly (gradually increasing the gas flow), I can get it to stay on at full blast.
• Almost without fail, when I leave it alone for several hours, I can tell, for whatever reason, it hasn't been able to ignite itself (most likely because it needs finessing to get it to light)

Given that the burner will stay lit at full blast after I finesse it (increase the gas flow gradually), but will go out otherwise, what might this be indicative of?

Answer 1

It might be an indication that gas regulator on your water heater might be going bad or incorrectly adjusted. It sounds like it's allowing too much gas pressure and blowing out your pilot light.

Your water heater should have a sticker that says what the regulator pressure should be set at. It will likely be listed in inches of water. Mine says 4"wc (wc = water column). Somewhere on the control box to your water heater should be plug that takes a hex key. This is a testing tap. You can attach a manometer to this port to test the output pressure. If it doesn't match what the sticker says then that's probably your problem. Manometers are fairly inexpensive. I bought one from Amazon (http://www.amazon.com/gp/product/B00D38K39Y). If it has two ports, one will be for the inlet pressure and the other for the outlet.

The regulator on your water heater might be user adjustable. You'll have to look at the service or user manual for your heater. On my water heater, it is not user adjustable. Granted the box is sealed with security screws. I bet if I opened it, I'd probably find adjustment knob or screw that's normally set only at the factory.