: I posted a couple of days ago about water hammering in my laundromat. Since then I fixed my water pressure reducer (Canadian fabrication/repair technology - ie. duct tape). I still have a hammering problem, but I'll sort that one out yet. My next question is on boiler systems and recirculation of the hot water trunk feeding all my wash machines. I have two 400,000 BTU heaters and two 100 gallon storage tanks and a recirculating system to keep everything hot. I have a recirculating line at the end of the hot water trunk that back-feeds to the input side of the recirculating pump. I expect that the whole hot water trunk should always be hot, right to the end so that the farthest machine won't have to go through several cycles to warm up. It's not. Do I need a back-flow preventer valve on this 1/2" recirculating line? Do I need a separate recirculating pump for this line? Do I need both? Any and all advise is greatly appreciated.

: Sincerely

: Richard Cross
richard, the recirculating line should extend to the furtherst point in your system,or lets say to the last washer.it should be connected to the hot water with a tt on the last washer then brought back to the water heaters and tied into the recirculating pump.there should be a check valve below the pump also a ball valve on each side of the pump.make sure you get the air out of the line. if you are putting a tee in this line to feed both ends of the laundramate put a balanceing valve on both sides so you can balance them out and get the air out. you can put a boiler drain on top of the circulator and use this to bleed the line.this line could be a 3/4 " also.