|
More boiler advice please
QUESTION:I'm following up a thread on the ignition probems of my Ariston
Microgenus combi (see http://tinyurl.com/ywc8c5 ).
After following up the advice I was given by the group I've cleaned up
the electrodes, cleaned the combustion area generally checked the HT
leads and changed the spark generator. However, the bastard thing
still has the intermittent ignition fault where occasionally it
doesn't fire properly, and puts on its red light and won't do anything
else until you press a button to reset it.
Following Raden's advice I've spent some time observing the boiler to
try to work out exactly at what stage in the cycle things go wrong.
>From what I can see through the little glass hole (which I've found to
be mainly more interesting than Saturday night telly) here's what
happens. There's actually no problem with the spark. However sometimes
only one "section" of the burners lights straight away - the flames
don't spread all the way along. The other section usually lights a
second or two later with a bit of a whoosh, I guess caused by the
buildup of unburnt gas. I'm assuming (although because it's so
intermittent I've not yet witnessed this) that the lockout is caused
when the dodgy section of burners doesn't light at all (it's the
section closest to where the detection electrode is) and the boiler
gets worried.
So what's the remedy for this? A clean up of the burners? The
combustion chamber did seem quite clean last time I was in there. At
the end of the last thread Fred suggested the problem might be to do
with the gas mixture, would my observations be consistent with that?
ANSWER: Just to follow up on this for the benefit of the archives, I solved
the ignition problem on my boiler. The problem was indeed to do with
gas pressure as Raden suggested. It was the "soft start" setting -
seems that there wasn't quite enough pressure at the beginning of the
ignition cycle to get all the burners going properly. One quarter turn
of the screw on the potentiometer and the problem was cured. Wish I'd
thought of that first, before dismantling and cleaning everything.
|
|
|
|
