Electric hot water cylinder with mains pressure cold water feeder tank - noise!

[DistantHillsBB]

Hello

Had a search but cannot find the exact answer.

We have an electric hot water cylinder which has a feeder tank on top.
The feeder tank is filled by the cold main water.

The problem is when the cold tank refills the mains pressure makes quite a loud noise disturbing the bedroom underneath the tank. No parts are vibrating its the sheer water pressure as it hits the existing water in the tank.

Is there a solution or workaround?
New valve?
Pressure reducing valve?

Thanks
Peter

 

[PlumbBobBob]

is there a shut off valve on the mains feed to the tank? if there is you could try throttling back on the flow a bit.

 

[ADM360]

sometimes a service of the float valve will calm down the effects of water hammer.

 

[DistantHillsBB]

is there a shut off valve on the mains feed to the tank? if there is you could try throttling back on the flow a bit.

Thanks for your reply. There is only one valve on the cold mains for the whole house and I don't want to throttle that back due to the demand on water in the property at times. Its a 9 bedroom guesthouse.

 

[DistantHillsBB]

sometimes a service of the float valve will calm down the effects of water hammer.

Thank you for your reply. Is a service something i can do or do i need a plumber? What is involved?

 

[WHPES]

Do you mean you have a fortic cylinder with an open bit on the top which has a ballcock? If so take off the ballcock and swap it for an equilibrium ballcock

 

[stevetheplumber]

They used to come with quiet ballvalves which had a dip tube on them but ive not seen one for years think they may have been outlawed a new ballvalve may be quieter or insulate the cupboard to stop the noise ? Im amazed that one combination cylinder can keep up with 9 bedroms

 

[DistantHillsBB]

Thanks everyone. I will try some of these options.
Steve sorry we actually have two of these cylinders and the showers are electric so there is not a huge demand on the hot water which is just really for the wash hand basins

 

[RobNice]

Sounds like you have a Thermal Store system. Try changing the ballvalve in cold water tank on top. Fit a "quiet type", such as Torbeck.
The system works by the fact that the bulk water is heated DIRECTLY by the boiler. This heats up much faster usually with ONE boiler firing, and then a coil in the cylinder, fed by mains water PICKS UP the heat and directs it to the rads or hot water.
Hope this helps.
Rob Nice.

 

[RobNice]

Forgot to say... Of course it may NOT be a thermal store, which means that you have a simple FORTIC hot water system which has a cold water tank on top of a copper cylinder, with immersion heater/s. Same remedy though. Replace ballvalve. Good luck. A pic will help if I got the wrong end of the stick..

 

[jtsplumbing]

Try changeing valve first ! lots of quiet fill ones on market, pop round local plumbers supply's, ! if no good then you may have to fit a Press red valve on supply to tank,

 

[DistantHillsBB]

Thanks JTS and Rob I will try out these solutions