flow check valves

gg2

My design has a properly sized Grundfos circulator on each zone. Experts recommend a flow check valve on each zone to prevent heat migration. Grundfos pumps, like other pumps, include a flow check valve. Are these valves sufficient to prevent heat migration or should a separate flow check valve be installed on each zone?

Unknown

not crazy

Not crazy about those inside flo check.. one little dirt can renderd them useless, sometimes, depending how's the system is piped, much harder to purge the system of air.

hot_rod

The pump check

should do the job. If it is primary secondary piping, sometimes you need a check on supply and return. Especially if the P/S piping rises straight up from the primary loop.



Those pump checks are ideal, they have a cone shaped valve and a soft seat. Low pressure drop and noise-free. Low cracking pressure also.



If it is an old system, with iron pipe for example, a Y strainer or dirt separator is a good idea to protect all the components in the system.



The only drawback to those intergral checks is sometimes over the summer air can rise up and get trapped in the pump volute and cause a no flow condition. Some installers try to always mount the circ horizontal to prevent a high spot trap.

jonny88

caleffi dirt seperator

tried it on my own system and will never look back.