Dave Plowman (News) wrote:
In article . com,
wrote:
I've worked out that the pilot light on my old Vaillant combi boiler
uses the equivalent of 60UKP of gas per year, does this sound right?
This means a new boiler would repay in 10 years on the cost of pilot
light gas alone.

Forgetting the cost of the gas used for a minute, you're assuming all that
energy is wasted. It's not - only a proportion is. The rest goes to
keeping the water inside the boiler warm so it doesn't have to heat up so
far when it fires next. More wastage when the system isn't in use though I
suppose.

When I replaced a 20 year old Ideal Mexico with a Worcester Bosch
condensing combi I was quite surprised to notice that I was spending 20p
(7.5kWh) a day just keeping the pilot light going. This was measured
over three summer months with heating off, electric hot water, and no
gas used for cooking (I was rebuilding the kitchen so cooker). So yes
60UKP a year is probably correct. The old boiler was pretty basic and I
suspect any heating effect from the pilot would be insignificant: much
of the day and night the heating is off and the heat would be lost to
the cold air in the flue.


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djc