"Bob M." writes:

"blueman" wrote in message
...
"Bob M." writes:

"blueman" wrote in message
...


Specifically, we have a 40 gallon gas-fired water heater on city water
with 3/4" inlet and outlet to the water heater and copper plumbing
throughout the house. We have 4 bathrooms and a kitchen. The city
water pressure comes in at about 85 PSI.

85 PSI is pretty high, you may want to invest in a pressure
reducing valve.

How important is it to add a thermal expansion tank or is this one of
those "if it ain't broke, don't fix it" kind of things?

Depends on your city water system. Do they have an anti-backflow valve
in the water meter?

I am not aware that there is an anti-backflow valve though I imagine
it could be built into the meter (which is one of those electronic
ones that they then broadcast wirelessly). Is there any easy way to
check by looking or would I need to call the city and/or try to find
and look up a model number.


If your T&P valve on the water heater hasn't sprayed scalding-hot
water all over by now, then you don't have an anti-backflow valve (or
DO have one, -and- an expansion tank). You would know by now.

Well the water heater is 5 years old and not a drop has come out of
the T&P valve and we definitely don't have an expansion tank... so I
guess e don't have an anti-backflow valve then. Thanks