Water pressure concerns at my home

[Andy12]

Hi experts,

When any faucet is turned on in my home, often but not always, water seems to have a bit more pressure and after 5 or 6 seconds, the pressure becomes normal. This happens even when faucets have been periodically used and not overnight or after a gap of several hours.

I observed the pressure gauge and normally it is at 65. But once when I checked, it was at 118 so I immediately opened a faucet and right away, the gauge came back down to 65.

There are no leaky faucets or toilets even when the pressure goes higher than 90 or even at 118.

The water utility confirmed that the street pressure in my area is 120.

Any advice? Happy to share any details as needed.

 

[Twowaxhack]

You need a pressure reducing valve or replace the one you already have that’s malfunctioning

 

[Andy12]

For the past few days, I have been trying to learn when the gauge goes up and found a very interesting and intriguing aspect.

A few minutes after the water heater starts running (Rheem, 50 gal Hybird), the gauge starts rising. And it keeps rising until I open a faucet when the gauge drops back to 65. After it stops running, I turn on a faucet and thereafter, the pressure remains constant at 65.

During night when there is no hot water usage and obviously the water heater doesn't run, I run a little water before going to bed and in the morning I check the pressure first thing and it is at 65.

There is a pressure reducing valve and also a thermal expansion tank.

Any ideas or correlations here?

 

[Twowaxhack]

Yes, you may only need thermal expansion control, not a pressure reducing valve. A thermal expansion tank is a popular choice to accomplish this.


You can read all about it, just google it.

 

[Andy12]

With no other water use, when the laundry machine is running (hot water wash) and draws water, the pressure drops from 65 to 50 and as soon as the machine stops the water draw, the pressure goes back to 65.

Is this normal?

 

[wpns]

There is a pressure reducing valve and also a thermal expansion tank.

Your thermal expansion tank has failed.