MY water heater is leaking or porting rather from the T&P relief pipe, I changed the valve but it is still leaking. I was thinking about a thermal expansion tnak until I took a pressure reading from my outside hose bibb and found that it was around 80, utility company says it should only be around 35-40 and that they do not have any type of pressure reducing valve installed. Builder confirmed that there is a backflow preventer installed. When I flush the toilet in the master bath I get a quick rush of pressure sound then all is normal, hot water coming into the washer runs slow then fast then slow then fast all in filling up the tub. Should I be looking more into a pressure reducing valve and if so can it be installed on CPVC pipe and where would be the best place to put it. Thanks

What is considered normal water pressure? There really is no such thing as "normal" water pressure. Since water pressure is influenced by the elevation of the reservoir that serves your neighborhood versus the elevation of your water meter, water pressure varies from property to property. Water pressure in the District typically ranges from 45 - 125 psi; however, typical residential systems are designed to function best under a pressure of 40 - 60 psi. If the water pressure entering you home exceeds this level, you should install a pressure regulator in the line to reduce the pressure to an acceptable range. This protects your equipment and piping in your home from damage from excess force exerted by the water. Symptoms of high pressure include "clanging" or "rattling" of pipes that occur when a faucet, dishwasher, or washing machine shuts off; water heater pressure relief valve malfunctions, and reoccurring leaks. The symptom of low pressure is typically a noticeable reduction of flow.

Pressure relief valves should be installed on your main water line before it gets in to your house, Good Luck.

John

So should I install a thermal expansion tank to resolve the T&P valve porting over?

I don't think that the thermal expansion tank will resolve you problem; you will need to install the pressure regulator valve, wait tell the other experts get on line and will give theirs opinion, Thanks.

John

afaroo is correct. You need to install press reducing valve. You can install it in cpvc line, just need the right adapters. I would install it in the house right before or after meter. Just so it is before any branch lines.

The only visible CPVC pipe to install the PRV on is either outside the house before or after the main shut off or inside the garage right before the shut off for the cold water supply to the water heater

Greetings Chief from a old Motor Mac on a LCVP.
The average house pressure's 45 PSI. If your's is in the 80's it's too high. That's why water towers are 100 feet high.

Builder confirmed that there is a backflow preventer installed. And would that backflow preventer be installed on the drainage or the water service? Regards, Tom