Water Heaters - Pressure Release Valve ??

Have a 5 year old gas hot water heater. Noticed that it had been dripping outside the house where the release valve vents to the outside. Decided to change the pressure release valve last evening after doing some research on the web.

Did so, but unfortunately this did not stop the leaking water. Decided to see how much water was venting through the system, and it would up filling up a five gallon "carwash" bucket in about three hours. :wall:

Does not have an expansion tank added to the source water line. We have strong pressure here, but I have not checked to see the exact pressure. Am leaning toward either adding an expansion tank or pressure regulator, but I thought I would seek other opinions beforehand.

Anyone got any thoughts that they can provide as to what may be causing the problem? Assistance would be greatly appreciated.

Hi paulisthewalrus,
Welcome to the DIY Forums.

First of all get a cheap pressure guage and find out exactly what your water pressure is. These can be purchased at most all home improvement centers and hardware stores. These will screw on to an outside water faucet. Run the water for a minute BEFORE you attach the guage. This will prevent air from giving you a false reading. Some will say that anything under 80lbs is ok, MY PERSONAL preference is 40-60lbs. This should be adequate for all your needs. If the water pressure is too high a Pressure Reducing Valve will solve this problem.

Is your water heater set super high? Your Temperature/Pressure Relief Valve may be pre-set at a lower temp. When the tank sets it builds up pressure. If the temp is set higher than T&P Valve pre-set it will discharge. This is a safety device to keep the tank from becomming over pressurized and exploding.

Try these first and reply back if you have further questions.

Good luck with your project.

Liks said check the presure on the water line there. If the new T/P valve is ok for sure. They come at 125 psi and 210oF Have they did anthing to the water lines there? Id go for and expansion tank there first.

ED ;)

Got the Mrs. to purchase a water supply guage while she was out. Checked the only outside line that I have (which is about 2 feet from where the water line enters the house)turned water on for a minute and turned off, put on meter, and got a 200psi reading (needle redlined). Double checked, still ~200 psi.

Checked another way, left the water on, put the meter on while the water was running, got soaking wet, and the guage said 160 - 180 psi depending upon how much I turned the faucet on.

Could that even be possible? What do you think??

Ed- the new PRV that I put on last night is 150psi & 210 degrees made by Watts - just like the one that came off. Regarding system water, they are doing lots of building in the area, but not in our subdivision. When we first moved out, blue pipe was being replaced everywhere - now almost everyone has copper in the ground. But conceivably they might have done something to the system lines.

Would appreciate any thoughts. Thanks.

Talk to the water company or the city there first and see what they say. If not then put a pressure regulator.

ED :thinker:

I looked on web for how much a pressure regulator would run me. When I saw the photo of one, the part looked familiar to me. So, I took some ceiling tiles down from the basement ceiling, and there sat a pressure regulator on the water line (on the house side of the only outside water faucet that I have). :thinker: I am not a plumber, but I rationalized that this was the reason the pressure was so high when I initially checked the psi (see earlier post).

Got make of pressure regulator, and pulled up the website, and found repair information for the part. On the troubleshooting page for the PR, it notes that if part does not function, it could cause the thermal expansion of water heater / cause PRV to activate. Tomorrow morning after everyone leaves, I am going to take part apart, and see if I can tell if there is a reason that it is not working properly.

If this does not work it should be replaced. Guess that I might need to add an expansion tank. Think that this a good plan......guys with more experience than me?

Thanks.

Cant you adjust it???? Most you can.


ED :thinker:

Residential PRV can be adjusted within the range of 25 to 75 PSI. If you have 200 PSI in the house, the PRV is shot and your house will probably experience a major flood inside of 24 hours! Get this fixed ASAP.

If a PRV is older than a couple of years, the likelihood of a successful overhaul is slim. Just put in a new valve.

The expansion tank is a separate issue. In this case you do need one, because even if the new PRv has a bypass function, this does you no good when the street is at 200.