On 30/09/2020 20:35, John Smith wrote:
On 2020-09-30 18:58:53 +0000, John Rumm said:

With modern modulating boilers that is less of a problem in the past.
A boiler with a wide modulation range is also desirable. The Vaillant
24kW models often go do to around 6kW.

John, thanks for your suggesting about the PCBs but at 20 years old I
think it's time to replace the whole thing and also it will be quicker.

One possible problem regarding rating and the way new boilers work - our
gas supply pipe to the current boiler is 15mm - is this likely to be a
problem for a condensing system boiler - I know it would be for a combi
boiler. Maybe there is a ceiling on rating or some makers only specify
22mm.

Digging up the kitchen floor is not a great option...





My neighbour has exactly this issue, boiler been running fine for
several years, board failed ..... British Gas came out and checked gas
pressure ... and now won't fix boiler unless he replaces 15mm supply
pipe with 22mm T His remonstrations that they have serviced it every
year and been happy are irrelevant.
He has just replaced the 22m pipe, and they have now replaced boards and
removed the 'do not use' sign.
Surprisingly they were happy he had changed gas pipe and made new
connections at meter & boiler.