DIY Doctor UK DIY Forums

I know how to replace a ballcock in a feed cistern. But the small top opening on the Polytank is making unscrewing it on the inside seemingly inaccessible. All the videos I have seen online show tanks with good access. Anyone got any tips?

Hi mgo,
You should be able to undo the feed pipe nut, undo the valve backing nut and slide out the old valve. That way you will only need to get a hand through the access hole.
Regards S

Thanks very much for the reply. I was intending to use the method shown in the videos of just removing the valve arm on the inside (gripping the arm/unscrewing the metal nut). But I will have to use the feed pipe method with PTFE tape because of the olive. The manufacturer has confirmed not to cut out a part of the top of the tank to get access as it would reduce the structural strength. I guessed it might which was why I asked them.

Hi mgo,
It’s a relatively easy operation but if you are fitting a part 1 valve you may have to bend the arm. A part 2 valve has adjustment on the ball arm.
Regards S