Potterton boiler efficiency

[sagesse]

We have a approx 30 year old Potterton Kingfisher CF100. I think it would be expected to run at 55% efficiency. However, we have a unique additional heat exchanger fitted. It's called an extension. The boiler - which incidentally I confidently expect to run for another 30 years - is in our kitchen, against an internal wall. It is surrounded by a huge airing cupboard, and the flue runs up through the house, warming two bedrooms as it passes through the brickwork, to emerge at roof level. Now, I'm energy conscious, for my pocket and the planet. I reckon to be downsizing (we have 5 beds, 3 receps, big kitchen, laundry room, heated garage, and 2nd downstairs bathroom) in 3-5 years. I'm being told to fit a new condensing boiler; it'll need re-siting in my laundry room to get an outside wall, or moving to a uncontemplateable position in the kitchen (and we lose the airing cupboard). Please tell me I am getting a significant improvement in efficiency through the current boiler's position, and that I'm making the right decision in leaving well enough alone! Last quarter's gas bill (11.9-27.11) was £181, 158 units, for 5-6 adults. One of our 3 showers is electric, and hot water is stored in an elsan tank in the loft. Thankyou

 

[D_Hailsham]

I'm being told to fit a new condensing boiler

Whoever is saying that either has a vested interest in you changing the boiler or does not know what they are talking about.

If you are contemplating moving in 3- 5 years, it's not worth changing the boiler. Any fuel savings won't cover the installation and maintenance costs of the new boiler (£2,500+). When you come to move, you can always offer to drop the house price by £1000 because the boiler is "old".

Last quarter's gas bill (11.9-27.11) was £181, 158 units, for 5-6 adults.

Presumably that was a summer/autumn bill. What's the annual usage?

 

[sagesse]

Thanks for your thoughts; going back from the last quarter, and some are estimates so use patterm is not absolute, £84, £186 and the winter period, £548. Forgot to add we cook electric and until this Sept, my 108 yr old aunt lived with us. However, I'm most interested to hear views on the heat I'm clawing out of my flue and it's contribution to efficiency. I can understand peoples' claims that a condensing boiler's flue doesn't emit much heat - presumably unlike ours, and I'd already concluded a new boiler wasn't worth it, but am I so wasteful! And are my arguments to a prospective purchaser valid?

 

[D_Hailsham]

Heating what is obviously a large house for £1000 pa is very good. If you do not have loft and cavity insulation it's even better. I had a 5 bed 1905 Edwardian semi (solid walls, sash windows, cellar etc) which cost £1300 pa to heat in 2005.

And are my arguments to a prospective purchaser valid?

That's a difficult one. All you can do is point out that you did not change it because it did not make economic sense to you. It's a bargaining point when you come to sell, just allow something extra in the asking price which you can knock off when they complain about the boiler. What you knock off will never be so much as the cost of changing the boiler

Incidentally, I am in a similar, but opposite, position. Moved to present house 4 years ago. The surveyor's report made comments about the age of the boiler and how it should be changed as soon as possible - no spares etc. Had it serviced after two years and the engineer, when asked, said there's no point changing it until it breaks down.

I'm still waiting.

 

[sagesse]

Well perhaps I'm doing better than I thought, though we too are solid walls, apart from the kitchen and bedroom extension at the rear; it's 30's detached, and I've doubled up the poor insulation and boarded the attic, and many of the upstairs bedrooms have built in wardrobes against outdoor walls, or blown vinyl type papers, which have made a significant difference. The double glazing is old style powder coated aluyminium in hardwood surrounds, and we have a porch which is kept shut under pain of death. We had an old double fronted Edwardian 20 years ago, with a full size cellar and original sashes, so I do feel for you, but they make lovely looking homes.
Many thanks for your words which make me feel a lot better, good luck with the boiler!