PRV or Expansion Tank?
#1
11-30-14, 12:37 PM
PRV or Expansion Tank?
I have an expansion tank at the electric water heater and a pressure regulating valve near the cut off where the water service comes in from the street.
Until a few days ago, the pressure stayed around 50 psi all the time.
Now, when all usage is stopped, the pressure creeps up to 95 psi over a few minutes.
1) How do I determine whether I have a bad expansion tank or a bad PRV?
2) Can damage occur to either of these by suddenly turning water back on after it has been off to drain a pipe?
Until a few days ago, the pressure stayed around 50 psi all the time.
Now, when all usage is stopped, the pressure creeps up to 95 psi over a few minutes.
1) How do I determine whether I have a bad expansion tank or a bad PRV?
2) Can damage occur to either of these by suddenly turning water back on after it has been off to drain a pipe?
#3
11-30-14, 02:28 PM
Super Moderator
Most likely a failing PRV diaphragm.
Could be.... Use some water in the home then shut off the main valve to the home. Does pressure rise?
Since its so rapid I would say PRV too.
Just a note the exp tank psi needs to be set at the house pressure psi...
#4
12-03-14, 08:12 AM
New Valve
Had a new PRV installed. Decided to not tackle the job as DIY. Problem solved. Thanks to those who helped sort out the problem.
