Plumbing Question - New Water Heater

[Grim]

So I bought a new water heater a couple weeks ago, as we knew the original one for the house was getting old and I wanted to have it replaced on my timeline, instead of having a catastrophic failure and being without hot water.

We had been experiencing periodic high pressure surges in the house, early in the morning, and early in the evening. During those times (approximately 5-10 seconds) the pressure would push water over in the toilet reservoirs causing them to run, or if a faucet was open, we'd get a lot of pressure out the faucet. Additionally, since the new water heater was installed, the over pressure valve would release water into the catch pan.

The plumber was suggesting that the issue was with the over pressure valve, but eventually mentioned the pressure reducing valve, which we replaced last week. That has stemmed the surges into the house, and I did not notice any this morning, but did find water in the catch pan this morning (a very small amount).

Is there something else I may be missing or overlooking in resolving this? I plan on contacting the manufacturer to see if I may have a faulty over pressure valve.

 

[chiefjason]

The over pressure valve coming into the house just reduces the pressure from the city lines to a pressure the appliances can handle without getting destroyed.

The pressure release on the hot water heater is to vent if the water heater gets too much pressure on it from heating the water. Do you have a expansion tank on the water heater? That would allow the hot water to expand without it leaking.

 

[Grim]

I do not have one, but that would make the most sense, as last night I noticed the water coming into the house from the main was pretty chilled, as evident by the presence of condensation on the exterior of my toilet reservoirs. I believe this makes the most sense, but I'm unsure of where to position the tank, as there is not much room on the return line going back up.

 

[Grim]

The house was built in 2005. I don't believe the expansion tanks were part of the code at the time.

 

[chiefjason]

They do the same thing, the expansion tank just does it nicer. You can figure out how to squeeze the tank in there or deal with the water. Unless you start getting a lot of water, then you might have a bad valve.

 

[Grim]

It was a very small amount, maybe 10 ounces max.

 

[BlackGun]

Put the expansion tank on top of the new water heater when you replace it. Problem solved. Every water heater needs one eventually.

 

[Button Pusher]

AMTROL ST-5 Thermal Expansion Tank made in USA. About $45

 

[jodyisaacs]

Put the expansion tank on top of the new water heater when you replace it. Problem solved. Every water heater needs one eventually.

Yep... fixed my leaking PRV issue.

Sent from my SM-N975U using Tapatalk

 

[Thatguy]

Have you tested the pressure coming into your home? Sounds like you need a new pressure reducing valve. If you have water filling up your toilets, and bypassing faucets you are over pressure. An expansion tank is to be close to the water heater on the cold side to allow the heated water to expand without the pressure relief on the tank from venting. Or the pressure reducing valve needs to be adjusted down.