This topic contains 5 replies, has 6 voices, and was last updated by  Nerdkid 3 months, 2 weeks ago.

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  • #4515


    Every year I ger round to thinking about upgrading the boiler. We have a standard hot water tank in the airing cupboard/ cold water tank in the attic/ radiator system fired by a 20 year old (plus) gas boiler.

    Obviously a sexy new condensing boiler would use less gas which is a given.

    However our old boiler chugs on and on and on without needing any atttention whatsoever bar an occasional looking at by an engineer. It has never let us down.

    I hear far less complementary comments about modern boilers and even tales of heat exchangers rotting away because they’re not made of stainless. Not many seem to just go on for ever.

    Two questions I guess:

    1) Will the savings on gas outweigh what I perceive will be much higher maintenance costs over, say , 10 years?

    2) Is it really greener to buy a new boiler rather than keep on with the old one until it dies?

  • #4516


    Some new boilers come with a 10 year guarantee, however you do have to service them every year.

  • #4517


    Unless it’s burning gas like an oil rig flare, I’d leave it.
    Mine is getting on for 20 years old now, it’s not the best efficiency wise, but I can’t justify the cost of a new high efficiency one. I just don’t have the heating on as much, especially now I’ve got my wood burner.

  • #4518


    Gas central heating. How Victorian.

    Have you considered a 21st C solution?

  • #4519


    It really all depends on just how much fuel you use and how inefficient your current boiler is. There’s a table here that gives an idea of what you might save:

    Remember though that these figures will be based on *average* use etc. They are also assuming that you don’t have TRVs fitted to radiators, timers, thermostats etc and thus the numbers are rather misleading. What you really need to think about is the percentages, e.g. how efficient is your current boiler and how much more efficient will a new boiler be. I’ve tried to explain it below.

    A new boiler will most likely be A rated (or maybe higher if you go for a really fancy one – they tend to cost even more though) for efficiency which means at least 90% of the energy gets converted to heat etc. i.e. for every £1 you spend on gas 90p gets converted into heat etc.

    If your old boiler is really inefficient e.g. a G rated one (70% or less efficient) then for every £1 you currently spend on gas only 70p gets converted to heat. Thus you’d be 20p better off per £1 spent on gas with a newer boiler. So as an example, if you’d normally spend £500 a year on gas, your new boiler would reduce that amount to something like £500 – (£500 x 0.20) = £400.

    However, installing a new boiler will cost a lot of money, likely ~£2500-3000 and thus you need to be using a *lot* of gas to come close to recouping the costs. E.g if we assume it costs £3000 to install the new boiler and divide by 10 years then you’d need to spending something like £1500 per year (which would save you £1500-(1500*0.2) = £300) on gas to even recoup the costs of the boiler!

    I’ve obviously not factored in maintenance costs for the old boiler. You’d need to make a guestimate for how likely it is to break and how often etc. Even if you factored in £200 every couple of years for repairs you’d still need to be spending over £1000 a year on gas to break even. As others have mentioned whatever boiler you have (even with a 10 year guarantee) will need to be serviced.

    Basically, if the old boiler works I’d stick with it for now. If you don’t already have TRV’s fitted on the radiators, a thermostat, heating timer etc then add these if you can as they will save money without costing loads. Also look at other ways to reduce heat loss by adding insulation etc.

  • #4520


    I’d only bother replacing it when it breaks, to be honest. Boilers are expensive, you might as well get the most use out of it possible. You’d save more money upgrading your insulation if you want to spend on increasing your home’s fuel efficiency.

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