Can somebody explain this please

[rpm]

Went to a job where the Saniflo was activating for no reason and found that when a cold tap was opened in other rooms water entered the toilet pan via the internal overflow of the dump valve in the cistern.

 

[Masood]

Pressure reduction in the cold pipework when another outlet opened causing the fill valve to just lift off it's seat I reckon..

 

[Best]

I saw a Fluidmaster bottom entry valve on a toilet cistern filling into the cistern and through flush valve when the basin cold tap was opened. It had been all installed approx 8 years.
I tried a new washer in the Fluidmaster, which stopped it doing that, but valve dripped water so I just replaced entire valve for same

 

[rpm]

Thanks guy`s, I was on the right line then with pressure reduction. Didn`t recognise the valve but it was just over 2yrs old.

 

[Best]

I should add that on the job I went to it was on mains pressure, but the flow to the house is poor, if that had any effect.

 

[rpm]

I should add that on the job I went to it was on mains pressure, but the flow to the house is poor, if that had any effect.

This was a 3 bed bungalow (2 en-suites) and as far as I know on mains pressure. Once I showed the customer what was going on and it wasn`t the sani I moved on to the next job.

 

[Staffy85]

, if the float valve is set at the right level and it isn't letting by, how can a reduction in water pressure cause that valve to let by when its being closed off by the water level? if anything that would only reinforce the seal being closed off by the water level, doesn't sound right or physically possible to me but that just my opinion, but that's whats happening here?

 

[rpm]

, if the float valve is set at the right level and it isn't letting by, how can a reduction in water pressure cause that valve to let by when its being closed off by the water level? if anything that would only reinforce the seal being closed off by the water level, doesn't sound right or physically possible to me but that just my opinion, but that's whats happening here?

Float was at a level to shut off but when cold water taps in the kitchen or the 2nd en-suite in the bungalow were opened then water poured into the pan.

It had been fine for 2yrs and I didn`t have a clue as to why but trusted the members who replied even though it didn`t make sense to me either.

 

[Staffy85]

with masoods post #2, think i realise what can happen, in the sense that water pressure is also playing a part in creating the seal and when that side of it drops then theres room for it to let by ?? not much but enough, probably down to the internal tolerances around the valve?

 

[jonnyswamp]

with masoods post #2, think i realise what can happen, in the sense that water pressure is also playing a part in creating the seal and when that side of it drops then theres room for it to let by ?? not much but enough, probably down to the internal tolerances around the valve?

Yep, I'm doing some ongoing work in a house and every time I turn mains off and drain down, the kitchen tap runs for a bit

 

[Staffy85]

Yep, I'm doing some ongoing work in a house and every time I turn mains off and drain down, the kitchen tap runs for a bit

ahhh! that explains why that shower head dripped a little...

 

[rpm]

I understand the pressure bit when you isolate the mains remove a toilet and water comes out of the open pipe when the customer opens a cold tap but couldn`t get my head around this one.

Thanks to everyone who added to my learning curve. lol