Why does your gas water heater go out after ten minutes?

Answer 1

Usually there is an overheat safety which shuts off the gas valve is the heat in the firebox gets to high for some reason. You need a professional to diagnose the reason the overheat switch is shutting off the gas.

Answer 2

The water heater is operated by a thermostat, check your settings ( panel at the bottom where the gas supply enters ) and make sure it is turned up, otherwise the thermostat may be having issues.

You may want to make sure all the covers are in place, and the exhaust is being vented outside, the thermostat does run along the outside of the tank portion, and heat from the bottom could trick it into thinking it is at the proper temp when it isn't. So if anything has been altered on the unit repair it to original.

Be careful of how high you set the temp, it will go high enough to burn you when the water comes out of the pipes, keep it in the suggested range.

Another possibility is that mineral build up on the floor of the tank is creating or acting like insulation. It would cause the unit to recover slowly, this would be the reason if your hot water runs out after 10 minutes and is cold after that.

If you have a bad dip tube on your unit your hot water will run out right away.

Your water heater may need to be flushed clear of what's built up at the bottom.

You should flush your water heater regularly to prevent this build up especially if you have hard water.

Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the drain and let it run until the water runs clear. You may see a gush of red,(rust) and possibly after that white grains,(lime or calcium carbonate). It should only take a few minutes. Flush monthly to keep it clear. If you have multiple years of build up you may have to drain the heater and put a can of C L R into it and let it set over night and then do the flush again.

Instead of "thermostat" I would use AQUA Stat as the probe is in WATER and Thermostat normally senses ambient AIR