Toilet filling when taps are turned on

lucyplease

Hi 
just thought I would try posting here before we get a plumber out incase it’s an easy fix! 

Our toilet bowl is filling when we use the bathroom tap/shower or kitchen tap. Sometimes it will start filling on its own too but mainly when another water supply is on. I have checked water pressure on the boiler and this is ok and also used plug unblocker liquid in shower and sinks incase this may have been causing it. 

I just wondered if anyone has any ideas ? I will try and attach a picture of our cistern 

unforeseen

It sounds like there is a blockage/restriction in your waste water pipework which is causing the toilet bowl to backfill from your bath/basin when emptied. 

DiddyDavies

Try putting a few drops of food colouring down the plugholes of the bath and kitchen sink then putting plenty of water down and see if the water filling up your loo has a tint of the same colour.
If you do them one at a time then you might be able to narrow down where a blockage or restriction might be.

Jeepers_Creepers

Hi Lucy.

Two ways for your toilet to fill - one is a back-flow from the soil pipe as suggested above due to waste water from the other sinks/basins. This would be pretty extreme, tho' - a very serious blockage. And if you flushed your loo, the bowl would almost certainly fill right up and nearly overflow!

The other cause is the cistern's filling valve is letting-by water even when it's full. You can tell if it's this by 'noise' - does it sound as tho' this is happening? Is there a 'hissss' or trickle of water? Can you lift the lid off the cistern and look? Or, look inside the bowl - can you see the ripple of water coming down the bowl side and landing on the water surface?

If it's the latter cause, then it would suggest that your inlet valve is letting by when the mains water pressure has dropped to an extent that doesn't keep it sealed shut. The new type of inlet valve - Fluidmaster-type - is very clever and uses the mains pressure to quickly shut off the valve when the right water level has been reached. If that pressure drops too much, the valve can ease open. And that pressure drop can be cuased by other taps being opened.

Either your mains water pressure is pants, or else the inlet valve is faulty.

First things first - how does your bowl fill? Is it coming up from the U-bend, or is it a trickle from the cistern?

lucyplease

Thanks everyone 

Jeepers- I have had another look and there seems to be a continuous small amount of water tricking into the pan constantly but only a small amount, barely noticeable. When the tap on the bathroom is turned it makes a sound like the water pipe into the cistern is opening up. (Sorry not the best description!) it sounds like the inlet valve from your message above - is this easy to replace or would we need a plumber? Il try and upload a picture of our cistern set up again as I’m not sure it worked before. I could upload a video to YouTube and paste the link but I don’t think that’s great Saturday night viewing so will try a picture! 

Thanks everyone for taking the time to reply, it’s much appreciated. 

lucyplease

Jeepers_Creepers

lucyplease said:

Thanks everyone 

Jeepers- I have had another look and there seems to be a continuous small amount of water tricking into the pan constantly but only a small amount, barely noticeable. When the tap on the bathroom is turned it makes a sound like the water pipe into the cistern is opening up. (Sorry not the best description!) it sounds like the inlet valve from your message above - is this easy to replace or would we need a plumber? Il try and upload a picture of our cistern set up again as I’m not sure it worked before. I could upload a video to YouTube and paste the link but I don’t think that’s great Saturday night viewing so will try a picture! 

Thanks everyone for taking the time to reply, it’s much appreciated. 

Let me just check what's on TV.

Uh-huh.

Go ahead and post that vid of your toilet :-( 

Actually no need for the vid - a photo will do. See if there's a make on the inlet valve.

That then leaves the question - is the inlet valve simply faulty (fair chance) or is your mains pressure completely pants (unlikely, since it was clearly able to pressurise your boiler at some point, so must be 1bar at least.

When you run your cold kitchen tap, what's the flow like? And if you put your thumb over the spout, how wet do you get? Ie - is it hard/impossible to stop the flow?

lucyplease

Haha yes watching a toilet flushing would be better than watching Saturday prime time tv! 

The water pressure on the boiler was low a couple of weeks ago as I thought this might have been causing the problem - I increased it to above one and it has stayed there since so that seems ok. 

When we first noticed the pan filling up we did poke around in the cistern and started to get a drippingleak on the pipe going into the cistern  (see picture) dripping onto the floor but oddly that stopped about a week ago on its own! 

I think the kitchen tap pressure is all good but will check with my thumb over it tomorrow. 

We had a new kitchen fitted a year ago and the sink/washing machine and dishwasher position were moved and I think now feed into the same outside drain as the upstairs bathroom - I’m not  sure if that would be relevant. (I have no idea about plumbing !) 
thanks again 

Jeepers_Creepers

So, I stay up aaaallll evening for this amazing photo - and you post one of the underside of the cistern.

Sheeeesh. Good job I fitted in the movie 'Unhinged' while I was at it. A ridiculous but engagingly tense road rage thriller.

Ok. There is water trickling IN to your bowl FROM the cistern? Yes? Cool. That means it has NOTHING to do with the drains or any other appliance, so stop dissing your dishwasher.

A good bit of info; you were able to repressurise your boiler to 1 bar, so that means your mains water pressure is at LEAST 1 bar too (or else it wouldn't have gone in to the boiler) so you don't need to test your kitchen sink cold tap any more.

This all means that the fault is almost certainly a faulty inlet valve inside your cistern - the gubbins that the hose is connected to.

THAT'S what we need a photo of. To replace it will require a bit of basic plumbing skill - undoing that hose fitting (once the water has been shut off) and then undoing that white plastic nut you see there - that will allow the valve to be removed from the inside. If you can get the EXACT same valve as a replacement, this should be a straight-forward job.

First, you need to get inside that cistern and post a photo on here. And one of the valve.

Jeepers_Creepers

Argh! I've just seen your earlier photo of the inside of the cistern! How did that get in front of my post? Jeepers.

Jeepers_Creepers

Looks like a typical Fluidmaster or a clone. Could you take a sideways photo too, please? And look closely to see if there's any writing on it.

(Some of these actually detach from the pipe that comes in to the cistern without having to undo anything. That would be cool.)