We've recently bought and renovated our new house and I'm about to install our fourth toilet flush mechanism in the upstairs bathroom. 

 

The problem first appeared not long after I installed the toilet with it refusing to turn off and with it constantly overflowing. I explained to b&q and had a second flush. After a few days it happened again but this time  I did note there was grit coming out of the bath tap alongside the loo in question.

 

Again I went back to b&q and in fairness they gave me a third flush only for it to happen again a few days later! Then it dawned on me that its likely the grit is going up the cold inlet pipe into the loo itself and jamming the flush mechanism resulting in if not being able to turnn itself off.

 

There is no grit coming out in any of the other taps in the downstairs kitchen, downstairs loo and upstairs bathroom sink. Its just in the cold bath tap and loo.

 

I have a feeling I caused it by unknowingly letting debris fall down the open pipes after the old bath and loo were removed when I was recently renovating the bathroom.

 

My question is, is there a mesh filter type connection I can incorporate between the insolator valve just down from the toilet baring in mind the pipe is standard 15mm copper? 

 

I just don't know when this will stop and a mesh filter maybe my only option if such a device is available?

 

Any help advice would be appreciated. 

 

Arnold9801

Do they get fed from cold mains or from cold water storage in the Attic? Which was common for cold water taps and toilets. Where it wasn't really potable water. Kitchen is always off mains. 

 

A small mesh filter will block fast if its that bad.  I'd whip the feed pipe off before the toilet and let it run into a bucket to see whats going on. Its maybe a single bit stuck at the isolating valve breaking down.