Toilet noisy when refilling

[alex1b]

I've got 2 fairly new Ideal Standard toilets with Conceala 2 cisterns (hidden, which makes problem-solving pretty difficult). When they refill, they make a kind of low-pitched howling noise. My first thought was that it could be debris in the ball valve, so I disconnected the valve from the braided hose inside the cistern and it still makes the same noise. The taps right next to the toilets don't make any noise at all, and work well. What could it be? Water pressure? When I turn the service valve to almost off, the noise gets lower-pitched the more I turn it, but it only stops making a racket when only allowing just a trickle through, which isn't very practical. Water pressure on the mains is 3.5 bar, which seems about normal to me...

 

[muggles]

They should probably have had flow restrictors fitted when they were installed - these are normally supplied with WC float valves in order to convert between high and low pressure systems

 

[alex1b]

Where would that be fitted, if it was? The feed pipe leads into the top of the cistern, then a braided hose connects the feed pipe to the inlet valve. Isn't it strange that the noise still occurs when it's just the braided hose with the inlet valve disconnected? The connection is in the picture attached. The other end of it has a second white plastic isolator on it. Thanks for the help!

 

[JohnD]

is that isolator fully open?

 

[alex1b]

Yeah, the plastic one at the end of the hose is fully open, as is the standard service valve on the copper pipework leading in. Tweaking the white plastic one closed a bit seems to make it quieter, but it means the cistern takes twice as long to fill (about 2 mins instead of 1 for full flush).

 

[polesapart]

Not familiar with this cistern, but often find Ideal's moving parts not up the standard of the ceramics.

Whole estate near me where bottom entry fill valves are failing one by one; I replace with with Fluidmasters.

Removing the valve, disassembling and cleaning may help. Otherwise replace like for like, easier than fiddling with a service kit.

Is this your valve ?

Armitage Shanks Conceala 2 Quiet Uni valve SV80367

 

[JohnD]

I disconnected the valve from the braided hose inside the cistern and it still makes the same noise.

this suggests that is not the valve, but the pipework. Which is why I suspected a constricting service valve.

 

[alex1b]

Hm, I think it should perhaps have a flow restrictor in it (since I'm pretty sure it's mains-fed and it says the pressure shouldn't be above 1.4 bar). Could high pressure be causing the noise? I think the flow restrictor is a little helix type of thing that should be slotted in where the pipe enters the cistern (the bit pictured above) but I can't seem to unscrew the white plastic bit. The plumbers who installed it should have put that in I think, but perhaps they didn't...

 

[JohnD]

the flexible pipe, and the ballvalve in it, are narrow and will constrict the flow quite a lot, but I am surprised it trombones.

I would go for a fluidmaster with high pressure restrictor anyway, it is a better valve, and it may be that it quietens the water flow even in the pipe, by slowing it.

 

[alex1b]

Any idea which fluidmaster I'd need, and whether it'd clip into the right bit of the concealed cistern as the existing one does? I've attached a pic of the one I've got, which fills from the side, and attaches to the hose via a sort of plastic sleeve you just push on.