4:45 AM wake up call, The Walls are alive

cj3 said:

Also I have been very curious wrt the lack of use of expansion tanks in the plumbing in CA. Every person who I have asked who is in the trades has rarely if every seen or used one, but no one really new why when I explained the need for them when using a PRV.


CJ

Click to expand...

For what it's worth, same situation here (Nebraska) - the word just hasn't gotten out here.

One plumber I talked to, when I finally diagnosed my foghorn-imitating, vibrating pipes and leaking WH T&P valve as a thermal expansion problem, recommended getting a higher-pressure WH T&P valve (!).

If you have a PRV, then you also have the expansion tank.
If the plumber left off the expansion tank, ADD ONE.

When water is heated, it expands.
Without room for expansion, it will force the T&P valve to release water.

You don't want to block off a T&P, or the water heater could explode.
http://www.waterheaterblast.com/

I can watch that link over and over again.

SteveW said:

One plumber I talked to, when I finally diagnosed my foghorn-imitating, vibrating pipes and leaking WH T&P valve as a thermal expansion problem, recommended getting a higher-pressure WH T&P valve (!).

Click to expand...

I hope that he was not a licensed plumber...
That is a dangerous "solution"...
An expansion tank is the right way to go - and a new PRV if the existing one is shot...

Thanks for all the help

Replaced the PRV and problem is solved

Never figured out why the noise started at 4:45 and ended at 5am but it is gone now.

CJ

Well, for one thing, if the person that installed the plumbing would of secured the piping better, you probably would not notice the pipes moving that much. As for the knocking, only thing that would solve, would be to put in some kind of pressure relief to stop the hammer effect, and also put rock wool, or some other kind of material between the pipes and where they go through floor to the walls to secure them from somewhat moving.