Toilet flushes when I run the shower or washing machine. Eh?

[davidd01]

Hello all,

I wonder if anyone infinitely more gifted than me on the plumbing front could help me with a problem I have.

When I run the hot tap on my shower or run the washing machine, my toilet has started flushing. I'm at a bit of a loss as to why this could be, and as the geniuses who built this flat decided to tile in the cistern, I can't even take the lid off to have a look.

I don't know if this is related, but about a week ago, the cold tap seized up with no water coming out, and only turning about 3/4 of a turn. That seems to me like the classic symptoms of a knackered washer which I just need to replace. It just seems like a strange coincidence that these two incidents should happen within the space of a couple of days.

The flat itself is only about 5 years old, so I hope worn out parts shouldn't be a problem. I also have a combi boiler if that helps.

If you do have any ideas I'd be really grateful if you could share them with me, as I can't really afford to start getting plumbers out.

Many thanks,
David.

 

[TicklyT]

If you mean your internal stopcock isn't opening fully, that could be the cause.

Equilibrium valves (Torbeck etc) used in cisterns are held closed by the water pressure in the supply. With the stop tap partly closed, the pressure in the pipework will drop when you open another tap, allowing the cistern float valve to open. If the cistern is already full, the water will run down the internal overflow.

 

[davidd01]

Thanks very much for the advice. I've realised I left off the fact that the cold tap was on the bath and not the internal stopcock.

That said, what you say about the pressure dropping so that the float valve opens seems to tally with what's going on. Why the pressure might have suddenly changed in my system is unclear.

I think the best bet for me is to replace the washer on my bath and see if that's some way connected as a first step.

(Unless anyone else reading has got any smart ideas!)

Cheers!

 

[John506]

When you say toilet flushes, do you mean just just trickles in the pan, or a full bore flush?

Does it do this on its own without touching the toilet, or is it when you flush it, it then just continues to trickle?

Only thing I can think of, is to take off your boxing in, run the tap then see what is going in inside your cistern when this happens.

 

[davidd01]

Hi John,

Thanks for replying. It's more of a trickle than a full flush (although it is a lot more than just a couple of drops).

It seems to do this after I've flushed (almost like a second wind!), but also when I've run the shower or had the washing machine on.

The really irritating thing is the cistern is completely boxed in. They haven't left an inspection hatch, nor is it as simple as removing a bit of sealant. It looks like I'd have to completely take apart the wall and retile if I want to have a look inside.

 

[Axel]

Modern crap. Give me a bulk standard 9l siphon flush and ballcock valve anyday....

 

[John506]

Then it may be what TricklyT says, or your siphon is getting stuck in the open position after flushed.

 

[davidd01]

Thanks John. It sounds like a possibility to me too.