*Detailed* Plumbing Question

[StriperrHunterr]

Ok, so this one I can give information on because it has to do with my house.

When we flush a toilet, especially, but also when we run hot water there is a banging sound the comes from the run of the pipes through the house.

It was barely noticeable when we moved in and has gotten progressively louder, like last night when it sounded like someone with a 9lb hammer was banging in the garage.

There are no leaks that we can see yet, but what do you guys think is causing it and what needs to be done to fix it?

Please, please tell me that it's a simple flow issue and not that our whole house that we've only been in for a year has to be re-plumbed. We bought a foreclosure, so we knew there would be some things wrong with, but this seems to be a bit much.

If it does need to be re-plumbed is that something that HOI usually covers?

 

[brunofishing]

Sounds like you may have drainline loose, or does the bang sound come when you shut the water off?

 

[StriperrHunterr]

Sounds like you may have drainline loose, or does the bang sound come when you shut the water off?

Only when the water is running. Turn it off, or let the toilet stop running, and it stops.

 

[win280]

google" water hammer"

 

[crackerdave]

Sounds like you may have drainline loose, or does the bang sound come when you shut the water off?

Do you know if your water pipes are copper or steel or plastic? Sounds like "water hammer," if they're copper.A few pipe straps might be all you need, if it only happens when you turn off the water or when a toilet shuts off after filling.
Check and see if the pipes in the basement move when someone turns a faucet on and off.If they do, just nail some pipe straps on where the movement is.
It also could be that your pressure is too high, and that's a simple adjustment.

 

[brunofishing]

Im not sure on that one, at my house i can hear my drain lines rattling as long as the there is watter running, im in a two story house, so my drain lines are ran in between the floors and it makes some noise.

 

[Wild Turkey]

Go find your pressure reducing valve. Should be right where waterline enters house. Sometimes near water heater.
Brass check valve about the size of a coke can. Turn the water on and watch it. It most likely is not restrained well enough. When the water comes on the drop in pressure makes the check valves pulse.
Whats your pressure look like. Is it weak?

 

[StriperrHunterr]

My pipes and everything are copper. I spoke to a friend of mine at work here, too, and he seems to agree with Turkey that it might be the reducing valve. That, based on your description, was where the hammering was coming from last night. It was on the same wall as the water heater in the garage, up and to the right as you're looking at the heater, and is about the diameter of a coke can but not the length (or with how it's mounted would actually be depth).

EDIT: The valve, does it have an adjustment cylinder on it? Like what a spigot would have if you took off the round handle?

The pressure is still good, but it pulses with the hammering sound.

 

[Wild Turkey]

It does have a screw adjustment to control pressure.
Typically you dont want over 60 psi inside the house. over that faucet seals fail, toilet valves fail etc.
My guess is yours is too high and when you open a faucet etc. the sudden pressure drop is causing the check valves to shutter.
Normally it would hammer 5 or 10 times until the pressure equalized then stop. Check your water meter and make sure the vlave there is fully open.
Also turn all water off at house and go look at the water meter. if its spinning you got a leak between the house and meter.

Simple answer is;
Bad pressure reducing valve or low pressure in the line from meter to house. Could be a leak, half open meter valve, bad meter, or leak.

edit. Right before the reducing valve should be a shut off valve to shut off water to house in an emergency or vacation. make sure its open.

 

[StriperrHunterr]

Ok, I haven't adjusted the valves at all.

I'll turn off the valve before the reducing valve and check for leaks at the meter.

Then I'll make sure that the valve at the meter is fully open. Then I'll re-open the main at the reducing valve.

If that still doesn't work should I look at adjusting the reducer valve? If so, how do I go about that without some manner of monitoring the pressure accurately?

 

[georgiadawgs44]

They sell a gage at Lowe's or HD that screws onto your hose bib. It has a dial on it that will tell you the highest pressure that was detected while it was monitouring the pressure. I have had to put 2 new regulators on my house in 15 years. If you get an initial rush of water that slows after a second when you turn on a fixture it might be a pressure problem.

 

[Wild Turkey]

simple hose bib guage from lowes that goes on garden hose bib.
Nothing running i would shoot for 50 psi-55 max.
I still think you have a low pressure situation between house and main. Could be city main issue, leak or valves partially shut.
Im going half shut cutoff at house or meter half on.

 

[StriperrHunterr]

Thanks guys, looks like a cool rainy night of testing for me. I appreciate all of your help.

Any plumbers that I can call to come to the Buford area for some beer and help, if things go that route?

 

[StriperrHunterr]

Ok, so it didn't take as long to bandage as I thought it would.

First I shut off the water at the input to the restrictor valve, the doggone thing is mounted with the arrow pointing down so I had to make sure that the only shutoff valve that I could see was upstream of the restrictor.

I then went out to the meter and checked, sure enough there was no movement of the meter, so no leaks between there and the house. I made sure that the valve at the meter was wide open.

I then went back into the garage and opened up the on/off valve all the way. The pipes still banged.

I adjusted the restrictor valve, first going 3 turns loosening the screw (which lowered my pressure but didn't do anything to relieve the noise), then going back 3 turns to the start position, then 1/4 more turn tightening. This raised my pressure in the house considerably, and fully eliminated the banging, but I can still hear the pulsing but very, very faintly.

I will go get a pressure guage either tonight or tomorrow morning from HD and do an actual test to make sure I am around the 50psi that Turkey states. The current pressure is higher than what we have had in the house up to now, but not even as high as some other houses I have been in, so I figure it was low before and is still slightly low.

Thanks to everyone for your help and please let me know if I've made a mistake in my thoughts or actions.

 

[Wild Turkey]

No just keep below 60 psi. If toilet starts to run in a month or two that means the city has bumped presure and u need to lower yours a bit.

 

[StriperrHunterr]

No just keep below 60 psi. If toilet starts to run in a month or two that means the city has bumped presure and u need to lower yours a bit.

Awesome, thank you guys again. These boards have to be the best ones around, and I've been on a few.