I have indeed purchased a 1500 rad, but it’s going to replace one that’s approx 1535, hence the need to extend. If take the Screwfix extension in my previous post, saw it in half, replace it with a chrome 15mm pipe cut to the right size, fit the 1/2 in male thread in the pic over the pipe and into the rad at one end, and an olive + 1/2 in female thread into the the valve, will that be leak proof? I’m worried that the telescopic bit is going to leak.