A friend called earlier this evening, and said that her boiler was
emitting clouds of black smoke, so she had turned it off. The Guy she
uses to service it - albeit that this boiler is a new one, and hasn't
had a service yet - was not available, so I went to have a look.
She noted that for the past couple of days the boiler had sounded
"different" when it first fired, although it is located in an outhouse,
so not too easily heard.
I took the front cover off the boiler, and turned it on. It went
through the usual pre-fire purge, then fired. It then "pulsed" three
times, before settling down to a steady and normal sounding fire. The
pulses occurred at approximately one second intervals, and with each
"whoosh" a cloud of unburnt fume exited the air intake of the burner,
though no flame was apparent.
I went outside and looked at the top of the flue, and there was a
fairly thick cloud of black fume exiting same. It struck me that the
whole problem was likely related to over fueling, although it had come
on suddenly, with no outside intervention.
I opened the air damper in several stages, until I got to a point
that the black fume disappeared, other that when it first fires, when
the fume is apparent for five seconds or so.
We are hoping that the service guy will be available tomorrow, so
that it can be set up properly with the flue gas analyser, fuel pressure
gauge and what ever else is required, but does anyone have any thoughts
on what has happened to the burner? It is an Electro-oil Sterling
There is some more history to this installation, in that the new
boiler was installed by a pucker oftec guy, with no problems -
initially. After a short while, it began to lockout, fairly frequently.
The installer returned, checked everything, seemed ok, so left. This
occurred several times, so the installer summons the manufacturer.
Manufacturers guys attend on numerous occasions, find no fault,
eventually change, one at a time, photocell, capacitor, control box, and
ignition module, finally giving up and fitting complete new burner.
There has been no further problems until now, some ten weeks at a guess.
As an aside, I see that they left the old burner on-site, not even
taking it back to HQ for analysis...