Heres an old Peerless boiler

[coolwhip]

I had to change out the aquastat. The boiler serves 5 apartments.

http://img76.imageshack.us/img76/7499/dsc00053je6.jpg


Question...on the bottom right you can see the PRV. There is no back flow preventer or check valve between there and the water heaters which are to the right.
Can the water backfeed even though pressure is greater on one side of the PRV than the other?

Please move this to pro section if need be.




[Edited by coolwhip on 09-26-2006 at 01:53 PM]

[ralphtheplumber]

Originally posted by coolwhip
Can the water backfeed even though pressure is greater on one side of the PRV than the other?
Yes.

Please see my backflow preventer post in pro/b&m a week or so ago.

You need an rpz anytime you're hooking up to the domestic water.

[coolwhip]

Thanks Ralph! :) I am sure that it is code around here and I did recomend that one be installed on my invoice.

[ralphtheplumber]

No problem.

I guess I should explain my other post.. the water won't normally go from lower to higher pressure, but the pressure isn't constant on either side.

Just because the gauge said 60 psi when you looked at it doesn't mean it's still 60 when everybody flushes.