On Tue, 27 Jan 2004 22:51:02 +0000, Bob Minchin wrote:


Zipadee Doodar wrote in message ...

Alan Butler wrote in message
news
Should conventional floor standing gas boilers with outside flue be
serviced each year? They seem to come each year and just hoover the
inside and clean it, check things over etc, never anything wrong with
it. Is this necessary? Or is it just a long check list of tick boxes
to make it a look like they are doing a lot. Bit like these 112 point
car checks etc

Yes, do it. I once failed to arrange an service, which meant the period
between services was actually 24 months. The build up of carbon was such
that the gas usage was very high, and flames were getting close to parts
they shouldnt. When the corgi opened it up, i was stunned at the build up.
i
hate to think what a further 12 months could have produced.


ZD


If your boiler is producing soot, then the gas/air mix is not set up
correctly and you are not getting good efficiency from the system.


These sort of boilers are now becoming very much the exception. They
really do need to be checked annually.

The use of the combustion analyser together with observation of the flame
picture (see FAQ) is a START on the process of checking. I beleive BG only
strip down the boiler and do a 'proper' service when the CO/CO2 ratio
exceed 0.8%. I'd be looking to do this is it were 0.3% or more. [Even
brand new boilers may have 0.1%]

Also to be checked are the following (which might be fairly trivial).
General condition.
Operation of controls. Thermostats get tired and overheat the boiler.
Looking for leaks (water).
Looking for spillage of flue gases at the draught diverter.
Checking the gas valve drops out in under 60s from the pilot extiguishing.
Checking that the dropped out gas valve actually cuts the gas 8-).
The burner pressure, this can drift with age.
....and perhaps if things are not as they should be...
inlet gas pressure.
Determining the gas rate of the burner.
Performing a flue flow test with smoke pellet.

The manufactuers may specifiy that the burner needs to be cleaned each
year however in general the instructions for this sort of boiler have been
long lost.

HTH

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html