Which size cap for Stelflow cylinder coil

[WLF85]

Hi All

I've disconnected Coil 2 on my Stelflow unvented Cylinder (old faulty solar panels no longer needed) and I'm looking for some brass caps to finish the job.

I measured the diameter of the male threaded bit sticking out of the cylinder and it's roughly one inch, so I bought some 1 inch female brass caps from Screwfix but they are too big.

So I went to the next size down (3/4 inch) and they are too small.

Does anyone know where I can buy these replacement caps?

Thanks

 

[WLF85]

Ignore me, I found it.