Water Heaters - Water heater pressure valve

I woke up this morning to find out that my pressure relief valve had been activated. I went outside to find hot water flowing out of the end valve. Did this happen b/c the temperature setting on the tank was too high? This has never happened before and my wife recently raised the temperature setting. This is on a gas hot water heater.

I turned off the water inlet and am letting the tank cool down before re-starting. Does this sound correct? Thanks.

The valve opens on pressure or temperature. Your activation could have been either one. Even if the temperature setting was raised recently, the hotter water will result in a greater pressure rise in a closed system. You could add a pressure gauge that will record the highest pressure reached. They are not very expensive and available at home centers and plumbing supply places. Look for a small hand that follows the gauge needle and has a small knob in the center to reset it.

Ken

If you have a pressure reducer valve on the house, it may be bad.