[mykawi]

I have never had any trouble with my hot water-heater, hot water is pooring out the preasurised overflow tube ( hot water ) on the side of the tank, had to turn the valve off to stop it, What could be the problem, this is a gas water heater.

[speedball1]

I have never had any trouble with my hot water-heater, hot water is pooring out the preasurised overflow tube ( hot water ) on the side of the tank, had to turn the valve off to stop it, What could be the problem, this is a gas water heater.

There are a few things that would trip your T & P valve,(see image).
1) There may be a bit of trash caught under the seat. Try jiggling the lever and see if it stops,
2) If you have a sprinkler system with a check or backflow preventer valve installed you will have to add a expansion tank,(see image)to the heaters cold water inlet. **OR**
3) The T & P valve could just be bad. In that case replace it.
Good luck, Tom

[Milo Dolezal]

Tom correctly lists three most common causes for Temperature and Pressure relieve valve at you w/h tank.

Usually, and most likely, it is that your incoming water pressure is too high or your temperature setting on your w/h is set too high. But high pressure is the most probable cause.

Check pressure with pressure gauge and if too high, reduce to 55 psi. Check thermostat dial setting. If set too high, set to fat red mark ( about 125 F )

From my experience, when T&P valve leaks, it has to be replaced. Reason is that when the "memory" spring was depressed for some time, it becomes weaker, and will not "read" the pressure as compared to a new valve. We always replace them as a preventive measure. They run about $7.00 at Home Depot.

[speedball1]

My bad! I should have asked, " how high is your house PSI?"
Purchase a hose bib pressure gage, (see image) and let me know. Goodluck, Tom