"bob haller" wrote in message
...
pressure tanks are installed to protect water heaters and prevent pressure
release valves opening when water mains have a check valve so water from say
a swimming pool being filled cant siphon back in the mains and add
contaminated water to the main in case of a water main break......

But I don't have a swimming pool! And I obviously don't have a check valve
on the water line coming into the house because the recent water main break
completely drained the house water lines. That wouldn't have happened with
a check valve in place.

I expect I'll have to call the county inspector to find out why the
expansion tanks are now required by code.

--
Bobby G.