Hi, I’ve done that before. Near the ICG it’s never spiked more than 5.
Water hammer from unvented cylinder
- Thread starter Taconite5
- Start date
Are you still getting 8bar near the washing machine T off?, if so, maybe another arrestor here.
Not since I put the PRV in. More like 4.5 during a spike now.
Well, if you're pretty sure that the mains pressure is 4.5bar then those pressure spikes are normal enought IMO, I'd still like to see the ICG NRV operating "normally", not with a zero dP, but looks like you would have to remove the upstream PRV to achieve this.
I can't find a exploded view of a ICG to see the check valve in this but imagind its spring loaded to avoid chatter even under normal conditions.
Remove the ICG and give it a rinse.
Make sure no aliens caught in NRV and spring pushes dome back into housing.
Make sure no aliens caught in NRV and spring pushes dome back into housing.
Caleffi were confident it’s not the NRV. But the more I listen the more I think it’s the ICG
I don’t have the old one as I put it in the bin!
It’s a new ICG!
Doesn't guarantee it's not defective or contaminated.
I'd still isolate the blender... If it has valves it's a simple test.
Yeah job for the weekend to have a play.
It really does sound like the group's PRV is knocking, bypass it and see if it stops.
If it is that's crazy it's been replaced and both had the same problem!
Trying to see this correctly - re the video of the gauge - there's one knock when the tap is opened and the water runs then another when the tap is shut and the water stops?
Not really - there probably isn't anything wrong with the valve in the control group, if it is being impacted by a pressure spike travelling along the balanced feed when a tap is being opened and the same being closed then that may be what's creating the knock at the valve.
May not be a problem with the valve, it's just creating that knock under these certain set of circumstances, wouldn't be the first time I've come across that. Again, bypass the valve to the balanced feed and see what happens
Not really - there probably isn't anything wrong with the valve in the control group, if it is being impacted by a pressure spike travelling along the balanced feed when a tap is being opened and the same being closed then that may be what's creating the knock at the valve.
May not be a problem with the valve, it's just creating that knock under these certain set of circumstances, wouldn't be the first time I've come across that. Again, bypass the valve to the balanced feed and see what happens
You said in your very first post in your Water Hammer thread that "I've noticed since the install was about 6 months old I'm getting a water hammer/knocking/clunking noise from my unvented cylinder whenever the cold taps in my house are open and closed."
Was the system trouble free for those first six months?.
Re Mixing/TMVs (thermostatic mixer valves), is any one of the cold valves, ie, say one on the (if installed) bath (cold tap) not fed from either a TMV or a manual mixer tap set and if so does it result in water hammer and that (ICV) PRV rattling?.
Was the system trouble free for those first six months?.
Re Mixing/TMVs (thermostatic mixer valves), is any one of the cold valves, ie, say one on the (if installed) bath (cold tap) not fed from either a TMV or a manual mixer tap set and if so does it result in water hammer and that (ICV) PRV rattling?.
It depends on the time of day. I think if there's positive pressure from the HW connection it's not as loud
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