Toilet cistern leak

[hansi]

I noticed the carpet was damp behing the plastic (quite old) cistern so I ran my fingers underneath the cistern flush to the wall and it was wet. Quiite how it leaks from there is difficult to work out as there are no connections there. Any ideas please? Thanks.

 

[just pumps]

In recent temperatures it could be condensation or remove cistern lid and look for splashing water as it fills.

 

[hansi]

Thanks, tried that, everything normal but when I looked on the underside, I can see little bubbles forming and dropping. Could there be a minute crack in the cistern? I have looked but it's difficult to see when it's full of water.

 

[just pumps]

Thanks, tried that, everything normal but when I looked on the underside, I can see little bubbles forming and dropping. Could there be a minute crack in the cistern? I have looked but it's difficult to see when it's full of water.

Well, yes anything is possible. As water runs downhill start with dry tissue at the top and work your way down to trace the source.

 

[Hot&Cold]

If it is a water leak,it could be in a few different places.

Have in the past used a drop of blue water dye in the cistern (dry the underside first) and leave overnight,if the drip is blue you have a leak from the cistern or connections .

Always clean out the cistern after dye testing

 

[hansi]

I can see where it's dripping, but obviously can't see the source as it must me a hairline crack somewhere. Have to get a plumber in

 

[just pumps]

If it is a water leak,it could be in a few different places.

Have in the past used a drop of blue water dye in the cistern (dry the underside first) and leave overnight,if the drip is blue you have a leak from the cistern or connections .

Always clean out the cistern after dye testing

Food dye will do it, comes in many colours.