Knocking pipes and Vibrating pipes

Calibos

House renovated and totally replumbed in 2010. No funny pipe noises for several years.

(Its not Heat expansion ticking/knocking I'm talking about)

I'm in a bedroom under a bathroom above and the mains supply runs up through a boxed in corner of my bedroom alongside the downpipe for the bathroom.

About two years ago I started to hear a knock when a any tap or device (dishwasher, Fridge water dispenser) was turned on or off. Not constant, just a knock when tap turned on and another singular knock when the tap is turned off.

My first thought was mains water hammer or something. Could our local pressure have increased in the last 2 years past some threshold that started causing a knock 3-4 years after our house was replumbed? One the one hand the Dishwasher and Fridge dispensor are connected to the mains coming into the kitchen afaik and seeing as they cause a knock it would point to the knock being mains related. Why only start 3-4 years after replumb though?

On the other hand when this knocking started happening about 2 years ago happened to be around the time when drilling through a water pipe in the floor upstairs caused me to run around the house turning off every valve in the house. Too much of a coincidence!?!? Turned off the mains valve in the kitchen but stopped the leak when I closed all the valves in the hotpress/emmersion. Got a plumber out and he spliced a joint into the hot water pipe to a bathroom that I had punctured. (Lucky it wasn't a Radiator pipe as that would have been much more hassle to resolve). After making that possible connection/realisation that the noises only seemed to start 2 years ago around the time of this screw up, I wondered if I had turned back on those valves correctly.

Could it still be a mains knock and it turns out the cause is my opening the mains valve back full when it should only be half open or half open when it should be full open etc? Or could it be one of the valves in the hot press that I reset incorrectly. Again, Full open when it should be half open or visa versa??

It also seems around the same time that when the cold tank in the attic is refilling a constant vibration is transferred to a pipe over my bedroom too. That would point to mains problem too I would have thought as remember the mains runs up through my room afaik. Yet the constant nature of this noise when refilling would surely point to a crappy ballcock valve.

I've gotten so confused. IS it all related, or is the timing of the punctured pipe and valve messing coincidental, is the constant noise on tank refilling related to the singular knocks on opening and closing taps or coincidental. All mains problem or all cold water tank ball cock valve related.

Any hints at how I can unravel this. EG, Do X to eliminate Y and if Y eliminated do A to eliminate B etc etc

GM228

Calibos wrote: »

House renovated and totally replumbed in 2010. No funny pipe noises for several years.

(Its not Heat expansion ticking/knocking I'm talking about)

I'm in a bedroom under a bathroom above and the mains supply runs up through a boxed in corner of my bedroom alongside the downpipe for the bathroom.

About two years ago I started to hear a knock when a any tap or device (dishwasher, Fridge water dispenser) was turned on or off. Not constant, just a knock when tap turned on and another singular knock when the tap is turned off.

My first thought was mains water hammer or something. Could our local pressure have increased in the last 2 years past some threshold that started causing a knock 3-4 years after our house was replumbed? One the one hand the Dishwasher and Fridge dispensor are connected to the mains coming into the kitchen afaik and seeing as they cause a knock it would point to the knock being mains related. Why only start 3-4 years after replumb though?

On the other hand when this knocking started happening about 2 years ago happened to be around the time when drilling through a water pipe in the floor upstairs caused me to run around the house turning off every valve in the house. Too much of a coincidence!?!? Turned off the mains valve in the kitchen but stopped the leak when I closed all the valves in the hotpress/emmersion. Got a plumber out and he spliced a joint into the hot water pipe to a bathroom that I had punctured. (Lucky it wasn't a Radiator pipe as that would have been much more hassle to resolve). After making that possible connection/realisation that the noises only seemed to start 2 years ago around the time of this screw up, I wondered if I had turned back on those valves correctly.

Could it still be a mains knock and it turns out the cause is my opening the mains valve back full when it should only be half open or half open when it should be full open etc? Or could it be one of the valves in the hot press that I reset incorrectly. Again, Full open when it should be half open or visa versa??

It also seems around the same time that when the cold tank in the attic is refilling a constant vibration is transferred to a pipe over my bedroom too. That would point to mains problem too I would have thought as remember the mains runs up through my room afaik. Yet the constant nature of this noise when refilling would surely point to a crappy ballcock valve.

I've gotten so confused. IS it all related, or is the timing of the punctured pipe and valve messing coincidental, is the constant noise on tank refilling related to the singular knocks on opening and closing taps or coincidental. All mains problem or all cold water tank ball cock valve related.

Any hints at how I can unravel this. EG, Do X to eliminate Y and if Y eliminated do A to eliminate B etc etc

Possibly a silly question, but have you consulted a plumber about it? Vibrating pipes I have foubd to be caused by a slight give in the pipe causing it to vibrate due to high pressure water passing through it, as to the rest I would not know but suggest it be given a once over by a plumber-not that that may find the answers either mind you.

GM228

Calibos

I called a local plumber the time I drilled into the pipe because at the time I'd didn't know whether it was merely a pipe feeding a bathroom sink or a radiator pipe which would have required a system drain and out of my DIY range. As far as I remember I was the one who also turned all the valves back on when he'd finished cutting out the section of holed qualpex and spliced in a joint. I only bring up that incident as the plumbing has worked perfectly before and after but the noise seemed to start around that time so it could be related...or it could merely be coincidental. I was actually very lucky to get the guy on such short notice. He popped down after he'd finished his Dinner/Tea.

In the past I'd be waiting days for a plumber to fit me in and as a result ended up fixing a lot of stuff myself which tbh gave me personal satisfaction and a desire to research any plumbing problem first and finding out if it was something I could fix myself before calling in the experts.

For instance, had a problem with a zone of our GFCH and with the help of the lads here was able to rule a few things out like the boiler and zone valves etc until I zoned in on the Zone/Controller unit. At that point the lads said to call in the experts and get a new controller but I kept investigating and figured out the problem. Offset mounting plate and connections on controller and if mounted on uneven wall would mean the controller was torqued on its mounting plate when buttons were pressed breaking the connections. Solution?? A Cardboard shim behind the controller prevented this torquing and connection integrity maintained. Hasn't given me a problem in all the years since.

Another time in this house pre-renovation and replumb the hot water taps stopped working. A Maritime Engineer uncle couldn't fix it and a plumber was called. Never turned up nor called nor was contactable. I googled for solutions myself. Did the old Shampoo bottle on the Kitchen Mixer tap trick with my brother holding that in place while I was in the attic. All that seemed to achieve was send the water out the overflow pipe emptying into the cold water tank in the attic. I did the Dutch boy finger in the dyke trick and stuck my thumb into the overflow. The only way through the system now was through the immersion feed to the cold water tank. A few seconds later a load of feathers came up through the pipe into the cold water tank. After removing the detritus and draining the tank and cleaning all was right as rain. Plumber arrived 4 days later without ringing in advance or apologizing and I had to tell him "Sorry, I ended up fixing it myself'. (different plumber to drilled pipe event).

Before I call a plumber for this I wanted to ask here in case it might be as simple as I didn't balance valves or something when I turned the water back on that time or that I just need to replace the crappy ballcock with a better antiknock ballcock valve or something like that.

GM228

Calibos wrote: »

I called a local plumber the time I drilled into the pipe because at the time I'd didn't know whether it was merely a pipe feeding a bathroom sink or a radiator pipe which would have required a system drain and out of my DIY range. As far as I remember I was the one who also turned all the valves back on when he'd finished cutting out the section of holed qualpex and spliced in a joint. I only bring up that incident as the plumbing has worked perfectly before and after but the noise seemed to start around that time so it could be related...or it could merely be coincidental. I was actually very lucky to get the guy on such short notice. He popped down after he'd finished his Dinner/Tea.

In the past I'd be waiting days for a plumber to fit me in and as a result ended up fixing a lot of stuff myself which tbh gave me personal satisfaction and a desire to research any plumbing problem first and finding out if it was something I could fix myself before calling in the experts.

For instance, had a problem with a zone of our GFCH and with the help of the lads here was able to rule a few things out like the boiler and zone valves etc until I zoned in on the Zone/Controller unit. At that point the lads said to call in the experts and get a new controller but I kept investigating and figured out the problem. Offset mounting plate and connections on controller and if mounted on uneven wall would mean the controller was torqued on its mounting plate when buttons were pressed breaking the connections. Solution?? A Cardboard shim behind the controller prevented this torquing and connection integrity maintained. Hasn't given me a problem in all the years since.

Another time in this house pre-renovation and replumb the hot water taps stopped working. A Maritime Engineer uncle couldn't fix it and a plumber was called. Never turned up nor called nor was contactable. I googled for solutions myself. Did the old Shampoo bottle on the Kitchen Mixer tap trick with my brother holding that in place while I was in the attic. All that seemed to achieve was send the water out the overflow pipe emptying into the cold water tank in the attic. I did the Dutch boy finger in the dyke trick and stuck my thumb into the overflow. The only way through the system now was through the immersion feed to the cold water tank. A few seconds later a load of feathers came up through the pipe into the cold water tank. After removing the detritus and draining the tank and cleaning all was right as rain. Plumber arrived 4 days later without ringing in advance or apologizing and I had to tell him "Sorry, I ended up fixing it myself'. (different plumber to drilled pipe event).

Before I call a plumber for this I wanted to ask here in case it might be as simple as I didn't balance valves or something when I turned the water back on that time or that I just need to replace the crappy ballcock with a better antiknock ballcock valve or something like that.

Maybe you have gremlins, best not spill any water on them!

GM228

whizbang

It sounds like you have decent pressure mains water. Is there any need to have this pressure...?
You could try to reduce the flow, and hence the pressure pulses, by closing down the mains stopcock. Maybe this is what you 'undid' by opening all the valves.

dishwasher, Fridge water dispenser

These are both using very fast switching solenoids that will cause a pressure pulse in the system; the noise from these is dependent on the pressure, and the amount of movement in the pipes.
With all your work, Its quite possible you cleared an air bubble in the pipes, which would absorb a huge amount of any pressure pulse travelling through the system.
But the most effective method is to reduce the dynamic pressure, simply by closing off the flow.

Also, there is no need to have high pressure feeding the storage tank. It can be trickle fed, with no noise whatsoever.
Fit a stopcock to the tank feed, and with a bit of experimentation, set the stopcock to the quietest flow, that still allows the tank to refill over a 24hour period.

Calibos

I'm 3m above sea level just off Bray Seafront which is a near continues slope down from the round wood reservoir so now that you mention it, I'd imagine Bray might have some of the highest pressure in the country I guess.

In work at the mo so will try turning down the mains stopcock valve when I get home. Assuming that turns out to be the cause which feels very likely, that's why more heads on the problem are a great help. While I reasoned that several things pointed to it being mains related I only thought in terms of pressure changes in the public system. Yet when I reasoned about the problem possibly being emmersion and cold tank related I was thinking about valve settings after the drilling accident. My brain failed to apply the emmersion valve rationale to the mains pressure line of thought. Doh!

And as you say, mains pressure could also explain the other constant vibrating pipe when the cold water tank is filling.

I'll post back how I got on. Thanks a million. 2 heads are better than one!

Now that I think about it the kitchen cold tap has a serious flow when opened fully and I feel that that to is something I only started to notice in the last year or two which matches the timeline and theory.

Can I assume that seeing as I need to close the stopcock valve a bit to stop the water hammer, that once that is achieved I can tweak it further to get a more moderate flow from the kitchen cold tap without any negative knock on effects elsewhere in the house. You've already explained how a slower refill of the cold water tank from the mains is desirable anyway, Its not going to affect the CH is it? Does the CH take its water via the cold water storage tank in the attic? Would I be right in thinking kitchen mains fed cold tap and attic tank refill rate are the only considerations I need to take into account when adjusting down the mains feed flow rate with the stopcock valve?


On a side note which now seems to be unrelated to my OP, the two valves in the hotpress beside the immersion. They are just valves on the cold water input and hot water output of the emmersion? yes? And 'balancing' merely means having both input and output valves open the same amount? Yes? Did I read somewhere that the should be 'half' open?

Calibos

Yep. That was it alright

I had the mains valve 100% open. I turned the kitchen tap on full and started closing the mains valve. It was like 4 full revolutions and still no change to the kitchen tap flow. It was only the last 1/4 turn remaining on the valve that started to affect the flow from the kitchen tap. Adjusted within that 1/4 turn range to get a more moderate flow coming from the kitchen tap.

Then got someone to open and close the kitchen tap, and the fridge tap while I was in the bedroom. No knocking!!

I then went into the attic and pushed down on the ballcock. Very healthy flood of water so my adjustment of the mains valve so much had not compromised the pressure for refilling the attic cold storage tank. I got someone to flush a few loo's. Mains feed to the tank still vibrating like fcuk and audible in that bedroom. This was only when the tank was close to full though. When I pushed the ballcock down to open the valve fully there was no vibration in the mains pipe. So looks like the reduction in mains pressure didn't resolve that noise but a replaced ballcock definitely will.

Thanks Whizzbang. You were the key to solving this and I put up with it for about 2 years for no reason as it turns out the fix was so easy in the end. One of the noises fixed immediately and the other annoying noise will be resolved after a trip to Chadwicks on Tuesday for a new anti-knock/vibration ballcock.

Is there a particular type of ballcock I need to ask for, to stop this vibration when the tank gets close to full?

hatchman

Get a fluidmaster pro great job to get rid of noise !

Calibos

hatchman wrote: »

Get a fluidmaster pro great job to get rid of noise !

Googled Fluidmaster Pro. All I could find was toilet valves.

Note, that its not the cold feeds to the toilets that are vibrating, its the mains feed to the attic cold water tank when its nearly finished refilling. Mention of toilets/loo's in previous posts was only in relation to creating a refill test/scenario for the attic cold water tank mains pipe.

Its a new ballcock for the main cold water storage tank in the attic I need.

I thought I had previously read about anti vibration/knock ballcock valves for storage tanks and special mounting plates for plastic tanks to stop the fittings warping the plastic walls and tilting the assembly but now that I go actively searching I can't seem to find anything but bog standard ballcock valves?????

Can anyone point me in the right direction?

whizbang

there's more than a few people seem to think low noise valves are not worth the effort. Particularly when there's an easy solution.

Central heating should not be using any water at all. If it is, the flow is very small, and wont be affected.

One of the the valves on your hot water tank could be for your domestic hot water, in which case leave them alone.
Probably the other is there to control the amount of CH that goes to the cylinder. Balancing means controlling the mix of heating to the radiators of hot water cylinder.

hatchman

Calibos wrote:

Googled Fluidmaster Pro. All I could find was toilet valves.

Calibos wrote:

Note, that its not the cold feeds to the toilets that are vibrating, its the mains feed to the attic cold water tank when its nearly finished refilling. Mention of toilets/loo's in previous posts was only in relation to creating a refill test/scenario for the attic cold water tank mains pipe.

They are also used on storage tanks, I have one on my storage tank which is directly over the babies bedroom I replaced ball cock with fluid master and there is no noise during filling and it allows nearly full flow of water right up to shut off point unlike a ball cock which trickles out water near its shut off point.

Put in the www as i cant post links fluidmasteruk.com/our-products/pro-series/pro-side-entry-fill-valve-with-heavy-duty-brass-shank.html

Calibos

hatchman wrote: »

They are also used on storage tanks, I have one on my storage tank which is directly over the babies bedroom I replaced ball cock with fluid master and there is no noise during filling and it allows nearly full flow of water right up to shut off point unlike a ball cock which trickles out water near its shut off point.

Put in the www as i cant post links fluidmasteruk.com/our-products/pro-series/pro-side-entry-fill-valve-with-heavy-duty-brass-shank.html

Ahh! Gotcha! Nice One!!

Going to actually wait till early December to do this as it turns out. Attic full of Christmas decorations at the moment (2 artificial Tree's, Boxes of Garlands, Loads of Fake decorative Christmas presents etc ie. A lot more Xmas decorations than one would normally expect) Very hard to do any meaningfull work up there with them in the way. Might as well wait till they are coming down out of the attic anyway for Christmas.

While I'm at it I want to get some lids for the two storage tanks. Plumber on the renovation in 2010 cheaped out methinks. Pretty sure they should have been included according to the regs. Would Chadwicks Plumbing have those tank lids and more importantly would they have the Fluidmaster valve linked above or is that something I'll have to order online somewhere instead?

We have two tanks because the space available under the slope of the roof didn't allow for a single taller and wider one but did allow for two thinner shorter ones end to end. They are connected by a pipe on the bottom.

Actually a question related to that. Remember, neither tank has a lid. The second tank that doesn't have the filler valve has a layer/film of dust on the surface of the water because the surface never gets agitated/mixed by a filler valve. Can I just scoop/blot this off with paper towels before fitting the new lids or do you think its a drain and disinfect job. The film just looks like dust. Doesn't look like bacterial scum, nor bird/bat sh!t or anything like that.