On Nov 24, 5:53*pm, "Tim Downie" wrote:
Appelation Controlee wrote:
We had the National Grid engineer here yesterday to do a gas meter
swap-out and, in the course of this, he did a pressure test on our
installation which resulted in him giving the thumbs down to our
central heating boiler because its gas control valve seeps when
rotated (although not when it's in the service position).

So, I'm looking for a new valve.

Is it not possible to service the old valve? *I would have thought that a
bit of disassembly, cleaning and reassembly with a suitable lubricant would
fix the problem.

Alternatively, I wonder if it would be legal to fit a new isolation valve in
series with the existing one?

Tim

The above is right. Most gas valves are not assembled dry but with a
lubricant.
It looks like vaseline (but isn't). Your gas valve has seen little
use, it will be OK. You could illegally DIY. Use a leak detection
spray/soapy water to check no leaks. Clean up mating surfaces with
plastic pan scrubber.