Pilot light in water heater lights, but burner won't ignite

[KayleeTina]

Hey all,
Our water heater went out earlier this week, we were able to relight the pilot and it worked fine. However today, it went out again and we could not get the pilot light to light. After doing some Google searches we replaced the thermopile. The pilot light now will light no problem, but the burner won't ignite. If anyone can help us out, we would really appreciate it!

 

[Twowaxhack]

Probably needs a new gas control thermostat if it’s a standard water heater.

What’s the name and model number.

 

[KayleeTina]

It is an AO Smith, model: GCV 40 300, serial: 1451A026332

 

[Twowaxhack]

Probably needs a new gas control or your gas pressure is too high.

Both can allow pilot to burn but the unit not fire.

By the serial number it’s almost 8 yrs old.

 

[KayleeTina]

Probably needs a new gas control or your gas pressure is too high.

Both can allow pilot to burn but the unit not fire.

By the serial number it’s almost 8 yrs old.

So we replaced the control panel, and started refilling the water tank and now water is pouring out of the relief valve. We've opened facets and opened the relief valve thinking there was too much air. But every time we try to open the water line it pours out again. We have never had an issue with the relief valve before.

 

[Twowaxhack]

Check your water pressure and if it’s under 80 psi replace the relief valve.

 

[KayleeTina]

Check your water pressure and if it’s under 80 psi replace the relief valve.

Okay, we opened the relief valve with the water line closed to release all the air and then started filling again and everything worked. After an annoying three days of no hot water and learning all the parts to the burner assembly, replacing the thermopile fixed the pilot light issue and your recommendation for switching out the gas control panel fixed the burner ignition issue. We have hot water! Thank you for the help!