Bathroom Fitting Question

Toilet cistern overflowing

We had a new toilet fitted two years ago, and fitter told us that the water pressure was low, so he removed a couple of washers within the flush system inside the cistern.

I've recently noticed that the water level in the cistern is at the top of the overflow, and I've noticed that there is a very slow trickle of water going down that into the bowl. It would appear that when the float rises, the inlet tap isn't being completely closed.

any advice on how to go about fixing this? Or do I get someone in? - it's only a small job.

I have tried adjusting the float, further down, so that the inlet closes at an earlier time, which works, and the water level is lower - but then several hours later, and the level has risen, and it's overflowing again. I think it must be a very slow drip - inlet not closing fully. I shall have to work out how to take the inlet apart to fit a new washer.

3 Answers

Best Answer


Presumably you have a push button system. Take off the cistern cover and establish which is the water inlet apparatus. This is usually on the right or left of the cistern, not in the middle. Attached to the plasticky bits of the inlet is what would appear to be an upturned cup. This is the piece that regulates the water level. If you have too much water in the cistern that cup needs to be further towards the floor. There should be a screw type piece which when you twist it clockwise or anticlockwise it either lowers or elevates the cup. Twist it and you should be in business. If the problem persists cut your losses and buy a new inlet from B&Q for £15, Cut off the water at the main, drain the cistern, undo the inlet pipe compression fitting, undo the big plastic nut holding the inlet to the cistern on the outside, take out the valve and replace it with the new one. Replacement is the reverse
procedure, but be very careful when you put on the final nut which connects your water system to the new plastic inlet. Invariably the water system nut is metal and the new inlet thread is plastic. Tighten it very carefully with your fingers making sure the nut is on the thread correctly. When it's on properly you can give it some welly. If it's not on correctly and you tighten it you will thread the bottom of the inlet and it's back to B&Q. Best of luck.



Answered 24th Mar 2012

photofinish contracts

Member since 6 Oct 2011

You will have to dismantle the inlet valve and check there is no debris preventing the valve from working correctly. Most valves can be serviced without having to remove the whole unit from the cistern. It is normally just a case of un-screwing the unit and cleaning it out and while you are at it replace the washer depending on which type i.e diaphragm torbex etc. Just make sure you isolate the water first. A novice should be able to do this in 15min max.

Happy Plumbing


Answered 30th Jan 2013

Your Plumbing

Member since 5 Dec 2011


Have you tried adjusting the height of the float operated valve (or similar)?
If it is still bypassing after adjusting then it would more likely be a maintenace issue which is a diaphram or washer replacement, depending on what type you have.
Last resort if still not working, replace complete inlet

Hope this helps


Answered 24th Mar 2012

A V H Plumbing & Heating Limited

Member since 5 Feb 2009

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