Water cylinder connection

[steveawright]

I need to temporarily disconnect the boiler from an old IMI Range Primatic cylinder and cap off the connections so the electric immersion can be used instead while the boiler is sorted.


I bought a couple of 28mm nuts and blanking discs but the boiler outlet/inlet fittings on the cylinder appear to be just very slightly larger than 28mm? I chose 28mm as the nuts fit snugly over the pipework (even though all I want to achieve is cap off the boiler connections). The pipework has an outside diameter of 25mm/1"


Can somebody please advise where I'm going wrong/what I need


Cheers


Steve