Flush valve size

[sotal]

Our flush valve on the toilet had failed. I think the cable was jamming so the valve wouldn't close and the cistern kept running.

I measured the old diameter which was 60mm and purchased a fluid master dual flush valve from Wickes which said it was compatible with 50mm and 60mm outlets on the cistern.

I got it home, had a quick read of the instructions and did as it says and replaced the rubber seal with the adapter seal. To make the 50mm threaded pipe for the 60mm hole perfectly. It did this absolutely fine and I tested it in the bath and it deals perfectly fine.

However, am I missing something as although that fits fine how the heck am I now supposed to fit that to the pipe that drops down into the pan? The pipe fitted inside the 60mm pipe and has a rubber and big plastic nut to attach it to the end of the 60mm pipe but now it is a 50mm pipe, it won't connect.

What is normally done for this? I feel a bit conned that although it does now fit the cistern it isn't actually usable, so although I bought for the correct size it won't work.

Do I need to get a 60mm one that is only 60mm instead?

 

[oldbuffer]

It's hard to tell from your description, and a photograph or two would help. However I suspect you have not removed the base of the old flush valve which is why the new one won't fit.
If its a close coupled WC, then you will need to separate the cistern from the WC pan. They are held together in one of two ways:
a. With a plate on the underside of the cistern, usually plated steel and usually rusted away. Two bolts go through this plate and the pan, and all is secured with two wing nuts.
b. With two bolts through the base of the cistern which then go through the pan and are secured with nuts. Various plain and rubber (con shaped) washers provide the water seal.
You will need to isolate the water going into the cistern and empty it of any residual water to split pan and WC. When you reconnect, you will need a new fibre washer (1/2") where the pipework connects to the shank of the inlet valve.

 

[sotal]

It is a concealed cistern. The cistern is wall mounted in the unit behind the toilet. The old flush valve failed, so I removed the cistern from the wall. Then removed the flush valve. The old one was 60mm so I purchased another that said it would work with 60mm.

However when fitting it is actually 50mm with an adapter rubber to fill the hole properly. This fits fine and seals well, however to connect the cistern to the pan, there is an L shape pipe. This L shape pushes into the pan and also went inside the 60mm pipe and had a nut/collar which sealed it.

I can't connect the pipe to the new flush valve though, so looks like I've wasted money on that one and will need another one. I'm guessing they won't accept a return as it has been fitted but in the other hand it doesn't do the job it says it would.

Unless there is an adapter that can be used??