hydronic heat

ac_3

I piped my boiler according to "pumping away" specs. I have encountered water hammer on the upper Zone when the zone valve closes. The boiler is wired cold. My theory is when the pump shuts off the head pressure on the supply side is pushing the ball in my honeywell zone valve closed to fast. Just like if the zone valve was in backwards. The solution should be to put a check valve in the supply after the zone valve, but I think it will slam shut the same way the zone valve does.
My question is. Check valve or a hammer arestor rated for hydronic systems. The only thing I found is a mini-trol rated for 200 degrees. This is a water system. No glycol. or anyother suggestions.


ac

Rusty Powers

slammin z/v

ac,

The trick I was taught for that problem is to disconnect one of the two return springs in the zone valve. This slows the closing action, and usually is enough to prevent unwanted flow.

Rusty

ALH_4

Bypass

You might use a differential pressure bypass valve to keep the zone valves from seeing high pressure when closing. Caleffi, Taco, Danfoss, Honeywell, and others manufacture these valves.

rob_26

zv

> ac,

>

> The trick I was taught for that problem is

> to disconnect one of the two return springs in

> the zone valve. This slows the closing action,

> and usually is enough to prevent unwanted flow.

> Rusty



I had the same problem the zv were on the supply side when i moved them to the return the problem stopped.