Old Plumbers Trick Keeps Gas Water Heater Pilot Lit In New Iberia

I had a customer this week in New Iberia who owned a rental home where the natural gas was turned off. When the new tenant moved in, the pilot light on the gas water heater would not stay lit. The pilot kept going out.

Fixing gas water heaters is one of many plumbing services I provide.

As this was an older model natural gas Ruud water heater from 1995, the kind that has to be lit with a match, it was obvious that the copper thermocouple was malfunctioning and needed to be changed.

I verified that the problem was the thermocouple by testing it for millivolts, and sure enough it was out of range when I tested it with my multimeter.

So I installed a new thermocouple. But, even with a new thermocouple installed, the pilot light still wouldn’t stay on. It would go out every time I released the pilot on the gas control valve.

Now what could be the problem?

I tested the new thermocouple to make sure it wasn’t bad, and sure enough it was fine. Nothing wrong with the new thermocouple. Hmm?

I knew the pilot was getting gas because the pilot would light, but it just wouldn’t stay on.

What could be the problem?

I tried adjusting the location of the pilot orfice in the burning chamber a few different ways, but each time the pilot light would still go out.

I was about ready to give up and order a new Unitrol gas control valve - as that was the only other thing that could be the problem - and then I remembered an old plumbers truck my dad did to light a gas water heater way back when I was a kid working with him. My dad Earl Billiot was a master plumber for 40 years.

I used my channel lock pliers and knocked on the gas control valve several times. This time when I lit the pilot it stayed lit when I released the red pilot knob. SUCCESS!

The Unitrol gas control valve has a rubber diaphragm inside it. Over time it gets worn out. This time it was stuck or had some debris on it and wouldn’t operate correctly after the gas was turned off. A few little taps did the trick and allowed the gas to continuously flow through to the pilot and burner assembly.

The tenant now has hot water.

Budget: 300.00

Location: New Iberia, LA