In article ,
"Malcolm H" writes:
I had a new Potterton Suprima installed in February 2004. It has operated
faultlessly ever since and I'm reluctant to have it serviced using the
principle "If it ain't broke don't fix it".
The burner flames look the same as when the boiler was new (blue with small
red flickers at the top).
Bearing in mind that natural gas is extremely clean, is there really any
need for frequent routine maintenance?
I'm not bothered by the cost but concerned that careless maintence might to
more harm than good.
Any comments?

My parents have a Potterton Suprima installed in 2000.
I have checked the CO/CO2 ratio a few times, but it's miles
off needing a service from that point of view -- in 3 years
it's increased only from 0.00064 to 0.00077.

When my Potterton Profile got to at least 7 years since
servicing (and probably longer as I have no record of when
the previous owners had it done), I decided to open and
clean it even though it was not showing any need for it.
There was no visible dirt inside other than the odd insect
which had been drawn into the air intake and setting
harmlessly out of the way. The cleaning took the CO/CO2
ratio from 0.00029 down to 0.00026, and by any stretch of
the imagination, wasn't worth doing verses the risk of
damaging something in the process.

Under British Gas's operation procedures, neither of these
boilers would have been serviced following an annual check
at these CO/CO2 ratios. Unless you have the ability to
measure the CO/CO2 ratio, you can't tell this though.
When a boiler starts burning poorly, it will deteriorate
very quickly -- the final stage isn't linear.

It is very important that open-flued boilers are serviced
annually, as the consequences of poor combustion, particularly
if caused by poor flue draw, are likely to be fatal.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]