Toilet cistern not automatically refilling after flush

[AVR2]

Our downstairs toilet has gradually got worse at refilling after a flush. It got to the point where tugging the flush handle *upwards* a few times would cause it to refill, but now you have to remove the cistern cover and briefly pull up on the black plastic thing with the slotted cross-shaped screw head you can see on the right of the attached picture. Once you've done that, it fills and stops as normal.

How does one go about fixing this?

 

[terryplumb]

looks like the float ( black circular bit at the bottom ) is jamming against the wall of the cistern. you could try to alter its position to create a bit of clearance .is that float valve recently fitted ??

 

[oldbuffer]

It may be that the float is catching on the side of the cistern. If so:

1. Flush, stop refill and turn off water.
2. Sponge / vacuum out remaining water from cistern.
3. Slacken nut connecting inlet pipe to base of threaded shank to inlet valve (underneath cistern, slacken no more than one turn).
4. Slacken nut (almost certainly white plastic) holding inlet valve to cistern. (Called a back nut)
5. Rotate inlet valve to ensure float clears sides of cistern.
6. Re-tighten back nut, making sure inlet valve doesn't turn as you do it.
7. Re-tighten nut connecting inlet pipe to shank. As long as you only slackened it one turn, you should get away without replacing the 1/2" internal fibre washer which seals the connection. (Flexible pipes generally don't have these). Make sure valve doesn't turn as you tighten.
8. Turn on water, check for leaks as it fills and correct as necessary.

If you can't get the float free by rotating it, you may need to fit a more slim-line model.

Less likely, but possible, diaphragm washer (seal) under the black plastic cap (top right of picture has gone hard.

Your valve looks like a Fluidmaster 400a fill valve, which would require a 242 replacement seal , but I can't be absolutely sure.

Pretty much whatever make it is, to replace seal:

1. Isolate water supply.
2. Remove cap and washer (Fluidmaster instructions available online).
3. Briefly turn water on with cup over inlet to catch water (flushes out debris). Turn water off again quickly.
4. Fit new seal.
5. Re-fit cap.
6. Turn water on.

 

[AVR2]

Thanks guys. The float *may* have been changed within the last year, but I'm not 100% on that.

 

[terryplumb]

watch the float whilst you flush ,it should drop down about an inch .if it doesn't its jamming on the cistern wall.

 

[AVR2]

I've inspected it closely now, and the float is *not* touching the cistern at any point.

When I flush it drops down, but when the flush has finished, nothing happens. If I give the float a gentle push downwards the refill happens, and then the float rises back up and stops the refill at the correct point as normal.

Since it's not hanging up on the side of the cistern, can I assume that there's something wrong internally with the float assembly?

 

[terryplumb]

fit a new valve , preferably a fluidmaster with a brass shank .

 

[dilalio]

fit a new valve , preferably a fluidmaster with a brass shank .

Just been to a fluidmaster I fitted several weeks ago... customer says it keeps letting by and they can hear it at night!
Worked fine during the 10 flushes I tried

 

[terryplumb]

10 flushes you tried today ?

 

[dilalio]

10 flushes you tried today ?

Yup

 

[terryplumb]

flush valve washer letting by ,level drops in cistern and inlet valve opening ? never had a problem with f/ masters.

 

[dilalio]

Nor have I... I put in both an inlet and dump valve. Have been told that board were faffing about with mains whilst they were on holiday. Could be detritus.
If they have further probs, I'll go back an dismantle and service it. Just annoying when you attend a leak that ain't there

 

[terryplumb]

know the feeling mate.