Just curious what I can do to fix this pipe banging irritation. Every
night at around the same time I hear the water line bang against the
wall or ceiling. It only happens for a about 20 seconds and then goes
away. It happens pretty consistently time wise. I know it's the
water company because no water is being used in my home. I've
actually been in the shower when this happened and there is a
noticable change in presure while this banging is occuring. In other
messages I red about a stand pipe, but am not sure what that is or
where it is. In addition, I have a water sprinkler system, so I'm not
sure if the banging is from the fire supply or the home use supply.
Any ideas how to solve this problem without tearing my walls about to
try and secure the pipe better? Should the water company provide
water that doesn't experience rapid pressure fluctuations? I believe
this happens when they do some kind of nightly maintanence on the
system, like a pump transfer or back flush. I've talked with them
briefly and know the fluctuations happen during this time when they
are performing this task. Thanks for you help and suggestions.
Ah. You have a residential fire sprinkler system. (?)
Solving this one may take some more detective work.
If there are check valves/backflow preventers on either service,
these can contribute to the banging during periods when the
pressure drops suddenly.
If there is a pressure reducing valve (PRV) on the household
service, it likely has an internal check. I have seen cases
where this internal check valve made godawful noises at night
when the utility suddenly drops pressure.
If there is a thermal expansion tank, this reserve of pressure
can make the banging period longer.
I have a hunch that solving this may take someone knowledgeable
on the scene to evaluate just what is happening in your case.
And I don't think the fix will be as simple as "adding a standpipe".
Yes, I think that's what he was referring to.
More properly an "air chamber". As long as they don't get
waterlogged over time, they can be effective in controlling
true water hammer, such as when a faucet is closed very rapidly.
Yes, it is a residential fire sprinkler system, required by the lovely
city I live in. I guess it's good in the case of a fire, but most
likely will only add to my water bill, because a larger main is
required. Sounds like you have a pretty good feel for this. The
noise occurs pretty much on schedule and lasts for about 10 seconds.
There is no water being used in the house so it is purely the result
of pressure fluctuations on the city water. I could actually see one
of the sprinkler heads move while the noise was occuring. Could a
pressure regulator on the main fix this. The weird thing is it just
started one day. It didn't start small and get worse. It sounds like
you are saying the the valve itself is causing the problem in doing
it's job to prevent a back flow of water or are you saying that
because it isn't doing it's job, the pressure change is causing a
water hammer? Are there regulations regarding the city provided
water? Thanks for you help. Dave.
You'll have to track down what components are actually in the
service line(s), such as regulator (press reducing valve),
check valves, backflow preventers, expansion tanks.
In the event of a sudden drop in mains pressure, a check valve
will slam shut and could cause a type of water hammer in the pipes.
I just mention that as one scenario, not necessarily what you have.
I doubt that anyone on here will be able to nail it down for you;
good bet you'll need someone competent to look the thing over.
Doubtful that the utility will cooperate.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.