Yesterday our very seasoned and experienced plumber came over to replace the washer in the kitchen sink because it was dripping. A newly installed bedroom faucet was leaking underneath the sink and my bathtub faucet has been dripping for a while. While the plumber was repairing the bedroom faucet the pipe under the bathroom sink downstair burst and put a 15 x 15 area under about two inches of water before we realized it, got his attention and the plumber was able to turn off the water from the city control knob.

He explained that my regulator had worn out over time causing the pressure to rise to about 90 and that caused the pipe in the downstairs bathroom to split. A $300 job turned into a $700 job and thousands of dollars worth of damage.

This is our third flood: Flood #1 - the waterhose on the back of the washing machine came loose during the rise cycle. Flood #2 - the toilet backed up. And here we are at flood #3. After doing a little research, I understand that high water pressure above 80 can cause problems.

Question: What are some basic (above general knowledge) plumbing guidelines for homeowners like myself who call a plumber and pay them dearly to handling plumbing needs?

It is a good practice to keep water pressure in your house at about 55psi. Pressure is regulated by Pressure Regulator. Average Pressure Regulator can be adjusted from about 25 psi up to about 75 psi. However, they can go bad w/o warning. So if you notice sudden increase in water pressure in your house plumbing than you should first check, and then replace, your regulator.

Galvanized and copper pipes are capable of carrying high water pressure for prolong period. In my area, we sometimes come across a house that has 160 psi and no problems. However, plumbing fixtures will not function properly under high pressure and will wear out faster. Moreover, flexible water supply lines may burst since they are plastic.

To prevent future floods, you can:
1. install water supply lines with Flood Prevention device. They make these for washing machine, too.
2. Periodically check your pressure. If high, adjust pressure regulator or replace it with new one
3. Pay attention to changes to your plumbing. Any new noise means something is going bad. Deal with it now, not tomorrow...

If the PRV hasn't been replaced yet, then consider having a bronze wye strainer installed inline before the PRV.

PRV failure is usually related to debris in the line becoming lodged in the seat/seats of the PRV.

A wye strainer will reduce the risk of larger particulate matter making its way into the PRV.