water hammer when last zone valve closes

terry_5

please give suggestions to this problem new boiler install with6 zone valves when last one closes baseboardrattles like a water hammer some supply houses have rec that i install a smaller pump the one installed is a series 100 b&g i installeda bypass from the supply to the return with no sucess please reply if your experience was simular

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kevin coppinger_4

its when the LAST...

zone valve closes...sounds as if the circ. is not shutting off. It wired ok? What zone valves? If honeywell you can pull one of the springs...A differential bypass valve would be the bees knees. kpc

tim smith_2

hammering

Check that the zone valves are in correct flow direction, seen alot that were put in backwards and they hammer then.

BillW@honeywell

Check for

long piping runs that may need more support, make sure valves are installed with the flow in the direction of the arrow, double check pump size. As a last resort, remove 1 spring, as was mentioned above. If you would like the differential pressure valve, check out our D146M models at any hydronic oriented Honeywell distributor.