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Electric Water Heater Pop Off Valve

Q. Tried to listen to you on Sat. mornings but need this question answered in writing. Question is about hot water heater and the pressure relief valve opening. Got a new valve and installed it but problem is still there with valve opening and water running out tube. I understand if pressure gets to high valve would open but is there anything internal that I could fix or just what is causing the pressure build up and valve relief opening. Water heater is electical and about 6 1/2 yrs old and I try to drain it from time to time also I do have a water softner installed as I live in Jefferson county.

A. Your electric water heater may be building up high pressure and popping off the pressure relief valve if the temperature gets too high or a steam pocket occurs in the water heater. It sounds like your pressure relief valve is operating correctly or it has grit or sediment lodged in the valve. Please be careful\ with the following suggestions as the water and steam can be scalding hot and hazardous.

There may be sediment in your valve. Try to wash any grit out of the pressure valve by pulling the little lever on the valve and allowing water to wash through it. This water may wash any grit out of the valve. Hold the valve until hot water comes out of the valve, not just steam.

Another solution is the steam pocket. The steam pocket occurs when there is an air pocket in the top of the water heater. "Burp" the air pocket out of your water heater by pulling the small lever on the pressure relief valve and holding it until water flows freely out of the valve. The water flow will indicate that your water heater is full of water and not just partially filled. Remember to put a bucket under the pipe on your pressure relief valve. A partially filled water heater may leave only a small amount of water around the top heating element causing it to behave like a pressure cooker pot on a kitchen stove. Steam can get much hotter and higher pressure than water so the goal is a full water charge in the water heater.

Another problem with electric water heaters can be a faulty water heater thermostat. The thermostat sends electric to one or both elements of the water heater to create the hot water. If the adjustable thermostat is faulty or set too high then it can cook the water too much, causing water that is too hot and the pressure inside the water heater to exceed the allowable range ... therefore the safety pressure relief valve releases the pressure build.

It could also be that the thermostat is set too hot and over pressuring the system. Find the instructions for the water heater or go online for the manufacturer for instructions and try adjusting the thermostat to a cooler setting.

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