Pentair Master Temp Gas Valve Buzz

[PSCel]

My heater works, however over the years (4yo), it has developed a buzzing noise just as it attempts to ignite. Recently on a cold afternoon it took several tries before it fired. The buzzing seems to come from the valve, can anyone look at this video and share opinions? We have never had issues aside from having to upsize our gas meter shortly after install when we found the heater would starve if we ran it at the same time as our on demand hot water heater. We never made any adjustments to the heater after that upsizing, could there be an issue of too much gas? Thanks for any and all help!!
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[ajw22]

Let's see what @swamprat69 thinks of the gas valve buzzing.

I think the gas valve needs to be replaced.

 

[swamprat69]

Most likely causes for a buzzing/chattering gas valve would be low/marginal voltage needed to operate the gas valve, worn/defective solenoid valve(s) that are not pulling in correctly or voltage dropping under load. Suggest pulling the 2 yelow wires off the gas valve and measuring voltage at the wires during the start cycle when the gas valve wiring is powered up for the cycle. Then measure the the voltage during the start cycle with the 2 yellow wires attached to the gas valve. There should be no significant difference in the voltages. Also check for voltage fluctuation when the gas valve is powered and buzzing. Other than the solenoid valve(s), the only other moving part(s) in the gas valve are the regulator diaphram and corresponding linkage. I have some hearing problems from VietNam making it difficult to isolate the noise in the video. You might also try putting a screwdriver on the gas valve body with the handle to your ear to get a better idea of the noise from the gas valve.

 

[swamprat69]

It might also be helpful to measure the amp draw of the gas valve and check it against the amp rating on the gas valve.

 

[PSCel]

Thank you for the advice, I’ll check it out.

 

[1poolman1]

My heater works, however over the years (4yo), it has developed a buzzing noise just as it attempts to ignite. Recently on a cold afternoon it took several tries before it fired. The buzzing seems to come from the valve, can anyone look at this video and share opinions? We have never had issues aside from having to upsize our gas meter shortly after install when we found the heater would starve if we ran it at the same time as our on demand hot water heater. We never made any adjustments to the heater after that upsizing, could there be an issue of too much gas? Thanks for any and all help!!
<iframe title="vimeo-player" src="IMG_5647 on Vimeo" width="640" height="360" frameborder="0" allowfullscreen></iframe>

Place your hand on the valve as it tries to open, won't hurt you. If it vibrates, check the wiring back to the control panel. If good, you can check the voltage, should measure 24VAC or a bit higher at the two wires on the valve. If so, replace the valve. Changing the meter should not have caused this issue.