Flush doesn't shut off

[david3456]

I am trying to identify a problem with a pneumatic flush mechanism that doesn't always shut the flow off properly after flushing When this happens the inflow is not fast enough to fill the cistern so it is not possible to flush again without having a fiddle with it to persuade it to close enough to fill. Then it works for a few days before doing it again.

I have increased input flow and it has improved the chance of a fill but since the cistern is under a worktop I can't see what's inside and I can't get my hand to the bottom of the cistern. Cearly the thing is not broken but just gets stuck somehow. What is the likely cause of the problem?

I get the impression this type of flush is fundamentally unreliable and seem unsuited for hiding away in cabinets. I have had permission to destroy the woodwork and fit a proper old fashioned flush but would prefer to explore further before going that far.

 

[Bosswhite]

Do you have a seperate visible overflow for this cistern ? is water running away from it.?

These days Toilet cisterns have an internal overflow which runs into the pan so people are made aware that adjustment of the ball cock is required.

 

[david3456]

Do you have a seperate visible overflow for this cistern ? is water running away from it.?

No but is it relevant when the outflow is preventing the cistern from filling?

 

[Charnwood]

What are you fiddling with to get the valve to close?

 

[tincup]

Hi
Do you know the manufacturer.
It sounds like a flush valve seating problem.

 

[david3456]

Hi
Do you know the manufacturer.
It sounds like a flush valve seating problem.

I don't know the make. What would cause the seat to be intermittant? (If a loose foreign body happens to get lodged it would be expected to dislodge with further operation.)

Interestingly, looking round the shed websites, air operated types don't appear to be fashionable any more.

Browsing the shelves, of the flapper, Fluidmaster and Opella, the Opella looks the most promising replacement. From what I can feel through the packaging, the plunger feels heavier and the top mechanism appears most direct - it looks as though frustrated button pushing is more likely to move a recalcitrant plunger.

 

[Charnwood]

Even though Fluidmaster and Opella are the same company, I would recommend the Fluidmaster over the Opella*.
If you can, source and buy the Fluidmaster PRO flapper.

(*On the QT, so would their National Sales Manager!)

 

[zanwan]

The flush mechanism is not reseating properly, could be debri from those cistern blocked you buy. You can either try taking it apart and cleaning, or better of just buying a new one. They dont cost much.

Depending on where abouts you are, we can replace them supply and fit for £135

 

[Charnwood]

Blatant advertising. Tut tut.

 

[Agile]

Depending on where abouts you are, we can replace them supply and fit for £135

I thought you were planning to rid Coventry of cowboys?

That price seems way too high!

Since its about 25 min work and the wage rate in Cov is about £8 an hour ( less in the shops, £5 to others and £3 for family ) then surely just £35 would be closer to reasonable?

Tony

 

[david3456]

The flush mechanism is not reseating properly, could be debri from those cistern blocked you buy. You can either try taking it apart and cleaning, or better of just buying a new one. They dont cost much.
Depending on where abouts you are, we can replace them supply and fit for £135

The only consolation to that is that it less than the amount my mother paid when it was replaced two years ago

I can do the job. What I want is an understanding of possible cause so I won't have to do it again in two years time. Since the problem occurs intermittantly, seal failure or fixed debris seems unlikely. If it is loose debris, operating the flush to raise the plunger ought to release it. There must be some other reason causing the plunger to not go home and to be unable to "worry" it back down with frustrated thumping of the button.

 

[Agile]

I have a standard cistern which sometimes does not shut off.

Cannot see exactly why not but I have added a weight to the top to encourage it to turn off. That seems to have helped!

Tony

 

[david3456]

I have a standard cistern which sometimes does not shut off.

Cannot see exactly why not but I have added a weight to the top to encourage it to turn off. That seems to have helped!

Thanks. At least that's identified someone else that's seen something similar. Given that I have seen it in two different places (though at least the other one would reset with the button) I am suprised it is not more familiar.

 

[tincup]

A picture would help identify the flush valve.
On certain types of flush valves the rubber seal blisters and then fails to seat properly with the base.

 

[Agile]

On mine its nothing to do with the seal.

Its simply that the mechanism does not return the plunger part to the closed position ( without additional weight added ).

Tony