Flow check valve

Raymo

We're in new York, and about to replace my 50 years old water heat boiler with 2 zones use circulators. Last time I check only one flow check valve was installed on zone 1 only which is same level as boiler location. I read some brand boiler manual piping.some have 2 flow check valves on same zone. And other manufactory only required 1 Valve for each zone. What's you guys think? I appreciate if someone can suggest me some answers🙏

EBEBRATT-Ed

Unless you have some unusual head head issue which is rare 1 flow check on each zone is fine

dopey27177

Flow check valves should be installed on each zone. It will help prevent phantom flow in any zone. Additionally, I put check valves at the end of each return before the main return to the boiler. Phantom flow is the condition where water can go up the return that is not in use causing some heat in the heating elements that are off line.

Jake

Raymo

Thanks for clear up my question, I was thinking to install a check valve at end of return line . I only have 2 zones , can I get away with just install one check valve at one of zones? And would you recommen swing check valve or spring loaded one?

dopey27177

Swing check valves are just fine. Install a check valve on each return. The phantom water comes from the zone that is on line not the boiler.

Jake

Raymo

Thank you for help

Ctoilman

Each zone needs its own check valve, nowadays the check valve is built in to the circulator pump.

Big Ed_4

Ghost flows happen by misplacing tees....