Hot Water Heater Trouble Shooting

[gab13by13]

My gas water heater is only 2 1/2 years old and it started cooking my water. I turned the thermostat down to low and it worked there for a while, then it started cooking my water again. I got my buddy to get me a new thermostat and after a while I had the same problem. The relief valve works, it releases the pressure into a bucket I have under it.

So, our town has a lot of old piping, our water is good but our pipes are slowing being replaced. The lines leak and the water company has been upping the pressure to fudge the leaks.

So I bought a water pressure valve today and found that my incoming pressure was at least 85 psi. My outside spigot leaked a little bit so it is at least 85 psi.

Now my town mandated that every home install a check valve inside the house to prevent back flows into the main lines. I am wondering if that check valve may have aggravated my issue?

Before I install the pressure regulator, which I will set at 55 psi, I am going to do a thorough cleaning of my hot water tank. My house is at the end of the water line and it took the water company years to find the valve so that they could flush out my line. I even showed them within a matter of feet where I thought the valve was.

Rant off because I also cut the grass and went shopping instead of golfing on this beautiful day.

High water pressure is bad for the washing machine, hot water heater, and the water lines.

[ret5hd]

1. man, i bet showers at your house sure feel good though.

[gab13by13]

2. I can water all my flowers from one spot outside.

[IA8IT]

3. Expansion tank is the answer. Exact same deal here mandatory check valve water heater pressure relief valve opening.

Beautiful day here too to deliver Harris Walz yard signs

[moniss]

4. Your water pressure should have nothing to do with

the temperature. Your burner is only supposed to kick in based on temperature in the tank. The probe in the tank and the temp sensor work together. Remember I said the pressure "should" have nothing to do with it. But there could be some fluke situation where the probe going into the tank has been damaged and so the sensor is calling for the burner to fire and probably stay on more than needed. I would be very doubtful that just reducing pressure is going to solve your problem. The probe(s) need to be checked for damage and if undamaged then your sensor(s) might be bad. You could also just have had a probe failure unrelated to anything to do with the pressure. I would recommend a plumber at this point because you don't want to have this "running wild" condition and risk a guest or child getting scalded and checking the probe/sensor/thermostat is more than most average DYI folks should really get into unless you just want to wholesale replace everything to be sure. But your probe is supposed to sense the heat and when the sensor part of the system sees it as meeting the thermostat setting it is supposed to shut down. That's the deal and reversed for firing up the burner. You could have a stray electrical issue with the system in which the signal to shut down the burner is affected also. Several possibilities but a plumber will put the test equipment on it and tell you quickly.

[jmowreader]

6. Sounds like a mercury sensor problem to me

Your water heater has three sensors on it: a flammable vapor sensor, a thermocouple and a mercury sensor.

The flammable vapor sensor detects flammable quantities of flammable vapor and shuts off the gas so the water heater won't burn your house down.

The thermocouple watches the pilot light, and if that goes out the thermocouple shuts off the gas to help prevent the house from burning down.

The mercury sensor is a sealed glass tube with mercury in it that sits in the water in the tank and monitors the water temperature. It controls the flow of gas to the burner.

These fail in two ways - they can fail so that the gas will never go on, or that it never goes off. These are not hard to change, but since you've got a tank of overheated water on your hands I'd recommend calling a plumber to change it - they are trained to deal with this.

[ProfessorGAC]

7. 85 psig?

That's enormously high.
Not counting pressure drop, a water tower would need to be 185 feet tall to deliver that pressure. (14.7psi for every 32' in height.) And again, that's not counting line losses.
Does your town have booster pumps? Or are the water towers 20 stories high.