Need reset code for hot water talk

Does the unit try to light? Is there an initial flame? Check for proper voltage at electrical connector. Check for proper gas pressure. Flame sensor maybe the cause of the failure.

www.richmondwaterheaters.com/Contact-Richmond-Water-Heaters

You can reset some models.... depending on gas control valve and FVIR design.
Some newer models you replace the sensor located on outside of tank.
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent
http://waterheatertimer.org/How-flammable-vapor-sensor-works-Therm-O-Disc-25VS.pdf

Gene

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Tom W must have been 'recommended answer' from past answers, and not live answer.
What did Tom's answer say?
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Most likely: Combustion chamber got too hot because air intake is clogged with dust, causing less air to flow upward through vent pipe ... the slowed flow of air caused combustion chamber to overheat.

What brand and model water heater?
Look at label on side of unit and add comment.
Otherwise call service tech to repair/ replace water heater and clean arrestor screen (air intake) and replace or reset parts as needed, depending on model number and brand water heater.

AO Smith, Bradford white, and Rheem are main manufacturers.
Each has slightly different repair protocol, and each gas control valve can also be different. So more information is needed.

Identify gas control valve:
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent
Rheem TRD/ FVIR glass vial
http://waterheatertimer.org/How-to-repair-Rheem-FVIR.html
How to remove combustion parts to inspect for Rheem glass vial and clean arrestor screen located under combustion chamber:
http://waterheatertimer.org/How-to-replace-thermocouple.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

copy following link for troubleshoot by gas control valve.
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

If this is Rheem/Richmond:
http://waterheatertimer.org/How-to-repair-Rheem-TRD.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

1) Could be the vapor sensor. That's a suspect.

2) General troubleshoot: clean burner and combustion parts, clean air intake, bleed air from gas line, check gas pressure. Color of gas flame should be clear blue, and flame should be strong, and no combustion by-product dripping back into combustion chamber. No chemicals of any kind stored in air supply. Plenty of fresh air. Water heater in hot attic needs more air. If water heater has igniter, then igniter has to be checked. Flame sensor must be positioned correctly and operational at time of combustion, or sensor will signal gas control to turn off gas. Gas control valve can be bad.
Open following link for possible illustrations and reading.
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

3) Specific troubleshoot begins with identifying gas control valve and reading the service manual.
I think the Rheem/Richmond power vent has intellivent gas control
Open following link to identify gas valve and download possible service manual:
http://waterheatertimer.org/How-to-adjust-water-heater-temperature.html#intelli

4) Take a moment and rate answer:
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

yep, for certain it is the vapour sensor tripped by the paint fumes. I work in the hvac field, on service and at least half a dozen times a year, i go to no hot water calls, due to the sensor being tripped off by kitty litter. the sensor is designed to be as failsafe as possible. Any slight detection of vapor, that could potentially be combustible and the ignition sequence is locked.

resetting your lock out for richmond power vent