Water heater diagnotics

[lwlobo]

We've just moved in to a new house, and I can't get the pilot light on the water heater to stay lit for more than one cycle. Looking for some advice or next steps.

It's a natural gas heater, I can get the pilot lit easily (electric striker) and it stays on after the sensor is heated up and I let up on the knob. Stays on indefinately, meaning I think the pilot gas circuit is good and the sensor is good. After turning the gas control to On, and turning up the thermostat, the burner comes on. At first it makes a nice whooshing noise and the flame is round around the burner and curling up like you'd expect. After a while, the flame becomes more random, not necessarily round, moving up and down, and the whooshing sound is decreased. The unit says it made for natural gas, but is there any way to check to make sure the orifice is correct?

I'm wondering about airflow, how do I check that the airflow is not restricted? The inlet screen is clean but I don't know how to check for restriction in the vent pipe. Or I'm wondering if the transition from the burner being on to just the pilot light is failing, although I checked that manually and the pilot stayed lit.

I took out the pilot and burner out and cleaned them (were't plugged or very dirty) with no improvement. I noticed the cold water supply valve was mostly closed but opening it all the way didn't help. This morning I noticed the first water out of the shower was a little brown.



What am I missing? Thanks.

 

[D.J.]

To check the vent pipe just strike a match (wooden type) and blow it out with it placed next to the vent hood on the top of the water heater. ( near the three legged pizza box insert looking thing) Have the match lower than it and make sure the smoke is drawn out the vent. I hope you can understand my visual clues. I can't help on the other part other than making sure the gas is in the on position, but it sounds as if that would not be the problem since it goes through a cycle!
!
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MOTORCYCLE TIRES

 

[rickairmedic]

What brand of water heater is it ? I ask this due to the fact Whirlpool water heaters have had some issues with their gas valves that are much like the issue you are having . I will add if it is a whirlpool you can call them with the model and serial number and if it is infact one of their problem water heaters they will send you new parts .



Rick

 

[MattT]

Used this today to troubleshoot my gas heater. It might help some.

GAS-Service-Manual

 

[Dale B]

I had that problem with a whirlpool from Lowes , I got so mad I made 'em take it back !! Did it right off the bat......

 

[lwlobo]

Good call on the match trick, D.J. Unfortunately that's not the problem, as there is a draw into the flue. The outlet air flow seems ok.


I called Reliance Water Heater Company (should have probably started there although I did read through the manual, especially the troubleshooting section). They suggested my flame arrestor might needed to be scrubbed. Apparently this is a ceramic disc that is part of the air inlet, underneath the burner. I'll try this tonight, the rep at Reliance seemed sure that would fix it. If it's so simple, I wonder why it's not in the manual?

 

[lwlobo]

I scrubbed the flame arrestor and it took care of the issue. The airflow is much better, and the burner flame has a move of an upward curl and is constant. The best part is, I can take a hot shower getting up 30 minutes early to start the water heater.