Loud and constant noise on running hot water taps

[johnmalkinson]

I hope someone will be able to offer me advice, or let me know if I need to call in a professional to deal with this.
Whenever I run any hot water tap, I hear a loud and constant low frequency noise (like a very loud hum), loud enough to get complaints from neighbours. If the washing machine is filling at the start of a cycle (does it use hot water from the immersion heater), I also hear the noise but not as loud.
The noise seems to occur when the storage tank in the loft is re-filling. I replaced the ballcock and valve in the tank but no difference. If I lift the ballcock to stop water flow, the noise stops immediately. If the valve is fully open, the noise also stops.
When I hear the noise, I can get rid of it by running any cold water tap. I think it is a pressure problem. I tried to close the mains tap a little, but it didn't seem to make a difference.
Can anyone offer any advice, or do I need to get someone in?
Thanks
John

 

[UKPITA]

Hi

The humming noise that you describe sounds like air trapped in the system..... as there are only 2 main types of causes of noises in the water system...

1st is Trapper air, which can cause a humming type noise as descirbed
2nd is water hammer which is more of a banging type of noise, normally caused by badly fixed pipework or worn washers...

I would guess its air, have you recently done any work on your system, ie drained it down etc...???

 

[johnmalkinson]

Thanks for getting back.
It is not really a banging noise; I could really only relate it to the kind of sound a fog-horn makes - deep and constant, not on and off.
The problem has gotten worse. When it started it would just last a second or two then stop, now it seems to keep going. It is too loud to really test how long it would last when running the tap (neighbours). It is loudest in the loft.
Now you mention it, I only really noticed that it started happening after having my new bathroom fitted.

 

[UKPITA]

I would go with airlock then and probably due to the way the new pipes installed??..

You can try draining down system and refilling slowly leaving the highest positioned taps open whilst filling to help the air escape... this can sometimes work, alternatively you can install an air vent in your system. (Costs a few £s depending on your plumbing skills.)

How long has this been going on for as air will generally find its own way out.... (most of the time)

 

[johnmalkinson]

It's been going on ages (months). I will try to drain then and refill from the bottom to see what happens. Failing this, I don't have any plumbing skills really so I will get someone in to do the work.
Thank you very much for your suggestions and help.

 

[Plamber]

I dont think its air. It sounds like its the tap cylinder. even replaceing the washer could stop it.

IF i was at this job i would change the tap cylinders.

 

[dontknowitall]

Is the water pressure really high? If so, you could try fitting a Pressure Reducing Valve on the incoming mains. They're about £45 so quite expensive to do this then find it's not the pressure so best to test it first. Also have your neighbours had similar problems with water pressure? It's common to find a pressure problem affects the whole street rather than just one house. If they have had problems then a PRV should cure this.

A local plumber should have a pressure gauge to test your water pressure which will take around 10 minutes altogether.

 

[evsy01]

its nothing to do with air, nothing to do with the taps and nothing to do with a pressure problem! its the diaphragm washer in the hot water header tank. if u dont feel comfortable changing it yourself then get a plumber to do it for you. part 2 ball valve and float will be less than £10 and half hour labour charge!

 

[johnmalkinson]

Thanks evsy01

I don't really know the right names for things! By hot water header tank I guess that means the tank of water (cold) in the loft that fills up the hot water storage (?) tank - the one in the airing cupboard that actually heats the water. The header tank refills with water when the hot taps are run (presumably to replace and top up the water that comes out of the storage tank). By diaphragm washer do you mean the ball-cock-controlled valve that the water comes out of to refill the header tank? The noise was definitely related to this (the one I had was ancient - i thought it was the source of the noise because playing around with it stopped the noise) so i already replaced this with a part 2 ball valve and float from B&Q, but no improvement.

 

[Billy Bob Bob]

this is a combination of high pressure or water hammer,> lack of pipe clips get a plumber to put a pressure gauge on your outside tap or w/macine tap 2-3 bar is normal over that and you need a pressure reducing valve as has already been suggested,also check other ballvalves for wear such as wc,s the trouble with this type of fault is it will reverberate around the whole house

 

[Plamber]

It could be the washer from the header tank but isnt it only happening from one tap? that would suggest it is that tap. sometimes the cylinder or inner part gets lose and vibrates when not opened fully.

 

[johnmalkinson]

Happening from all hot water taps (even when washing machine is filling at start of warm/hot wash).

 

[Plamber]

Ah my bad, thought it was only happening from one tap, (dont know why) Probably is the washer in the coldwater tank that feeds your hot water cylinder.

 

[Leon]

I would have said the same except he already changed it....
Does the inlet to your header tank have a service valve (little screwdriver operated thing to turn off the water)? If so trying partially closing it. I would also suggest adding a pipe clip or two near the tank, and check the pipe isn't rubbing against a floorboard or joist.

 

[payney1974]

its nothing to do with air, nothing to do with the taps and nothing to do with a pressure problem! its the diaphragm washer in the hot water header tank. if u dont feel comfortable changing it yourself then get a plumber to do it for you. part 2 ball valve and float will be less than £10 and half hour labour charge!

Definitely agree. If you have already changed it though is there a stop tap in the airing cupboard below? this could need changing too.

 

[bravolima]

Did you get this fixed as I have the same problem but there's to many 'i know what it is.....' comments.

If so what did you find was the cause? It started when I replaced the shower head with one that flows more water. I have cold tank in the loft and hot tank in a cupboard in the bathroom......

That's in advance.

 

[kay-jay]

it will be the float valve in the header tank. bet you a fiver! i know he's replaced it but i would say the washer is seated incorrectly or the valve seat is of the wrong sort high/low pressure!

 

[Tomlad]

Definitely agree. If you have already changed it though is there a stop tap in the airing cupboard below? this could need changing too.

I would say try swapping the ballcock valve as well these can make a right noise at times similar to the one you describe, easy to swap as well

 

[billybob150811]

dont know if this is any help if a piece of debris gets stuck inside the seating the float doesnt close off smoothly it bounces causing shock waves thru the pipework if its debris the noise will get louder and faster as the ball valve closes off because its bouncing faster and the hum changes tone i tend to agree its the ball valve and float poss wrong seating needs to be high pressure a 6" float sometimes smooths things but i would check the ball valve first to bravolima there are many possable causes were all offering our best advice freely thats why there,s more than one view point each situation will be different

 

[leelister6]

Got to go with the ball cock in the header tank. Mebbe some crap got flushed into the new one after fitting? Turn water off, remove ball cock, strip and clean and fit an isolation valve on inlet pipework before it enters tank. Turn water back on and open isol valve slightly to flush any crap through. Refit ball cock and jobs a good un. (That'll be £40 please!)

 

[TipTop]

replace domestic ball valve with a 'torbeck' ball valve and if noise persists you could try turning down your mains water stopcock slightly before going for a pressure reducing valve on the cold mains

 

[kay-jay]

replace domestic ball valve with a 'torbeck' ball valve and if noise persists you could try turning down your mains water stopcock slightly before going for a pressure reducing valve on the cold mains

he'll be over the moon with your rapid response......only 8 months too late :arabia:

 

[uzume13]

Hi. I can see this is an old post but would like to know if it was resolved? I have the same issue, also it's not clear if the advice was only for people with an immersion cylinder. I have a combi boiler, appx 5 years old and this noise from the hot water has happened pre and post boiler being fitted. Many thanks.

 

[kay-jay]

Hi. I can see this is an old post but would like to know if it was resolved? I have the same issue, also it's not clear if the advice was only for people with an immersion cylinder. I have a combi boiler, appx 5 years old and this noise from the hot water has happened pre and post boiler being fitted. Many thanks.

Describe the noise you hear uzume. Also do you hear it more at the tap or the boiler?

 

[kris]

Hi. I can see this is an old post but would like to know if it was resolved? I have the same issue, also it's not clear if the advice was only for people with an immersion cylinder. I have a combi boiler, appx 5 years old and this noise from the hot water has happened pre and post boiler being fitted. Many thanks.

Sounds like tap or shower cartridge prob

 

[Dotty]

Please register with us to receive additional answers to your problem.

 

[Dan]

You'll find more up to date threads than this in the main Pluming Forum. But I'm reply to this so we bump it up the list and get the pages indexed correctly because of the new update we've had. So just ignore this if it's all old news.

If you do reply, keep it polite and professional. You can disagree with the above posts, and just be professional with your reply.