David wrote:

On Sun, 12 Nov 2017 11:14:03 +0000, Ray wrote:

I have a license copper lines boiler. It fries up immediately a d then
the flame goes out and right back on over and over.. I ha e changed the
ignition assembly figuring it was a sensor but didn't help. The flame
was a strong blue yesterday and now today it starts blue and then
weakens within a couple second it goes out and then relights.

Dirt in the gas feed to the pilot light?

We had an old floor standing gas boiler and every year or so small bits of
dust would get into the small diameter pipe which fed the pilot light and
would then block the gas jet and the light would go out. The gas would cut
off, the dust would drop back under gravity, and then the pilot would
light again, only to slowly fade out.

A quick blow through of the pipe (and sometimes a gentle clean of the
pilot jet) would sort it.

Always happened when it was cold and I was in a hurry.


Cheers


Dave R

I had that with large volumes of iridescent dark grey flakes of very
light stuff. I assumed it was due to some chemical reaction between the
gas and the service pipe or some component of the meter and pipework.
Anyone seen such a phenomenon? I had to keep taking the gas valve apart
(to a greater degree than was entirely safe or legal I think) and
blowing out the passages and valve compenents with compressed air.



--

Roger Hayter