multi zone - water hammer

vtan · November 3

I had a weil mclain cga recently installed and also replace baseboard via radiators in one of the zones. experience a very odd behavior. I have 3 zones using zone valves. zone 1 is basement, zone 2 is first floor and zone 3 is second floor. zone 2 has the new radiators. when zones 2 and 3 are active, then turning off zone 3 creates a rattle in the zone 3 pipes (water hammer). when zone 3 is active by itself, turn it on and off does not do that. I have bled the system already, it does seem to be a bit better but not entirely gone. never had this problem before zone 2 was replaced by radiators. any suggestions is greatly appreciated.

hot_rod · November 3

What type of circulator? A pic of the zone valves. Flow is going through the valves in the correct direction?

A zone valve hammer is often caused by excessive flow velocity that the valve is trying to stop.

vtan · November 4

attached are photos of my setup. also the expansion tank is on the hot side, not sure if this is the reason. Excessive flow does that mean the pressure is too high.

hot_rod · November 4

what mode is the 007e in?

It was designed to manage zone valved systems, eliminate banging

some would suggest removing one of the springs inside the HW zone valve

This slows close off a fee seconds

But watch for ghost flow as it also reduces close off pressure

vtan · November 5

It has an orange light and according to documentation it is in normal mode. do you think when it goes into green mode it'll be better?

by the way, the water hammer sound is not at the valve. It is somewhere in the second floor for the zone in question. Not sure if this additional data point is helpful.

Also the boiler is running 20 psi, can that also create a problem?

mattmia2 · November 5

is the 20 psig cold fill or with the system hot? how high is the highest emitter above the boiler?

hot_rod · November 5

the noise from a water hammer can often be heard or felt where the piping is not secured well enough

The force, or shock wave starts at the zv the further it travels the more extreme the noise, often times.

No harm in trying the pump in the other mode if it is selectable It sounds like it takes a week to learn and adapt

vtan · November 6

20 psi is the cold pressure. i have checked the hot pressure and it was slightly higher than that.

@mattmia2 is emitter the same as the air vent? I have posted some pictures on this forum and there is only 1 air vent. It is on top of the expansion tank.

multi zone - water hammer

Comments

Categories