Electric Water Tank Pressure Valve Leak

[jonstar]

Hello all,

My 50 gallon electric water heat tank started to leak at the pressure relief valve. It is a very slow drip.

I am wondering how I can diagnose the cause? I will note it is a very old tank - 20 years - which I inherited when I bought the house.

One thing I have noticed is that some of my faucets seem to have higher pressure. For example, when I turn on the kitchen facuet, I feel like it recently was coming out with a bit more force/pressure than I am used to. Could the leak and this pressure be connected?

I am also in the process of sourcing a new tank given the age of the existing one but if I could fix the leak in the meantime, that would be great.

Any advice is much appreciated.

Thanks,

Jon

 

[TomFOhio]

Your water isn't overly hot is it? If not I would just buy a new pressure relief valve and see if that stops your leak
since your going to get a new WH. Turn the electric off and the water and then drain it down to where the relief is at. After
replacing fill it up and open a couple hot faucets and get the air out and then turn the WH back on at the box.

 

[jonstar]

Thanks for that advice.

Is it dangerous in its current state? My water is not overly hot. Seems normal to me.

 

[Twowaxhack]

Probably not dangerous but it should be serviced ASAP.

 

[arctic bill]

do you have an expansion tank for the hot water, and do you have an check valve of the main . it could be that when the tank fill with cold water and then heats up it has no where to go.

 

[jonstar]

Thanks everyone. I do not have an expansion tank.

I just got a new tank. AO Smith, Electric, 50 gallon.

The tech installed the new one yesterday. I left a bucket overnight and when I checked it, I saw water in the bucket. He came back and said that happens sometimes with new tanks and he just tapped the pressure valve a couple of times to make sure the pin is in. I also had him lower the temperature (it was set at 140F which is too hot with kids). After he left, I noticed water again in the bucket which I had emptied. I realized that he only lowered the thermostat at the upper panel and not the thermostat on the bottom. I have now lowered the lower thermostat - both are now set at 120F. Could that have been the cause of the leak afterwards or do I need to call the tech back?

Thanks everyone!

 

[Twowaxhack]

You need to check for thermal expansion.

 

[jonstar]

Sorry for this follow up but how do I do that?

 

[Twowaxhack]

Put a pressure gauge on the drain valve of the water heater, the type that screw onto a hose faucet. Open the drain. Home Depot or Lowe’s has them. Any hose faucet would work but since your water heater is new, it should be convenient.

Then go to your bathroom and run the hot water for 3-4 minutes. This will put cold water in the tank and cause the heater to start heating.

Go watch the gauge and see if the pressure starts to climb.

During this period that you’re watching the gauge it’s important not to run any water, including any automatic ice makers.

 

[Twowaxhack]

Or you could just skip all that and install a thermal expansion tank and make sure your water pressure is 80# or less.

 

[jonstar]

Thanks. I will do that. I just ordered one from Amazon (but see discovery below).

In the meantime, I took a look at the main valve and noticed that I have a pressure gauge there. Two photos attached.

The pressure meter reads a bit over 80. Is that a problem for me? I do hear thudding or some vibration sound in the pipes sometimes.

EDIT: One further inquiry. Is there a way to lower the pressure at the main?

 

[RS]

Yes, with a pressure reducing valve, a regulator, they are fairly common and inexpensive.

 

[jonstar]

Hi RS. Sorry I am not following. Is it possible for me to adjust the pressure based on what you see in the photos?

 

[Twowaxhack]

Your pressure is high but only by a few pounds if that gauge is correct.

The pressure reducing valve can be adjusted but yours in the pic looks old. I wouldn’t try to adjust it unless I was prepared to replace it. Looks pretty old......

The noise you describe that occasionally occurs can be caused by a pressure reducing valves like you have pictured is starting to fail.

You need to install some type of thermal expansion control.

Google it and read about your options.

 

[arctic bill]

because you have a PRV it probably has a check valve incorporated in it. therefore as 2 hacks said You need to install some type of thermal expansion control. I am not impressed with the tech, he knows nothing .

 

[jonstar]

Thank you both. I will take a look at my options. Is installing a thermal expansion tank relatively simple/relatively affordable (which I get is subjective)?

 

[jonstar]

A quick question folks.

I spoke to a plumber today who was too busy to help me do the work but not too busy to talk to me.

In his view, as long as I remove the pressure reducing valve at the main, then the problem will be solved because it stops the one way action of the water. That sounds reasonable to me but what do I know. I would be grateful for your thoughts.

EDIT: Will doing that detrimentally affect my water pressure? Of course high water pressure is bad but I don't want low pressure either!

FURTHER EDIT: I was just browsing the water heater manual and it says that a thermal expansion tank must be installed in a closed system. Straight up annoying.

 

[jonstar]

So, I have now removed the PRV. I had checked with my neighbours and they believed their pressure was just "OK" and some said "not good". I never tested their pressure. So, unfortunately, with the PRV off, my pressure now sits just below 100 PSI. It stays that way even as I let the water heat back up (assuming because it is no longer a closed system).

I frankly was surprised about this increase but I guess it explains why the previous owner installed a PRV (though why not a thermal expansion tank too....?). Is there any way for me to manage this? Is my only option to get a new PRV (since the old one was very old) and a thermal expansion tank?

Thanks again.

 

[Twowaxhack]

Install a new PRV set to 80 psi. Install a thermal expansion tank with the tank precharged to 80psi.

Problem solved.

 

[RS]

Twowaxhack is right, just because you have 100 now, in the middle of the night it might be a lot higher. With some municipal water systems the pressure varies with demand. Any more than 80 is not good for plumbing fixtures.