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Why a new boiler will not reduce your gas bills this winter, but will cost you up to £5k


Jo Alsop

Heating Hero

The Heating Hub

Jo explains why 'investing' in a new boiler will not save you money this winter and how to spend your money wisely.


For most people a new boiler will be their biggest waste of money this year. The smart money is on improving the efficiency of your existing boiler.

This week I heard that installers have never been busier, with a rush to ‘upgrade’ boilers to offset the rise in gas prices come winter.

I also read with horror one claim from an ‘online’ boiler installation company (where boilers are fitted without a survey, left at their factory settings and not paired with an advanced control) that a new boiler would save a household up to £580 per annum.

Boiler installation companies are capitalising on the rise in fuel prices to present a hypothetical efficiency jump from a G-rated boiler to an A-rated boiler (and in a large home) to suggest a 4-5 year payback.

There are two problems here. Firstly, the vast majority of households already have an ‘A-rated’ gas boiler as they have been mandatory of 17 years. Some may have a B-rated boiler but next to no-one has a G-rated boiler. Secondly, most A-rated boilers are C-E rated in the home (Energy Savings Trust). To put it another way, boilers that are certified to be 90-91% efficient under test conditions are only 75-85% efficient in practice.

Why? Because condensing gas boilers need to be set up quite differently to non-condensing boilers, but 17 years on 99% of installers have not received adequate training in condensing boiler technology and do not set them up to reach their efficiency potential, which can be over 94% when done right.

What does this mean for households? It means that swapping out your old, poorly performing A-rated boiler for a new, poorly performing A-rated boiler will not reduce your fuel bills this winter, but it will add thousands of £s to your household expenditure this year.

Even if you’re swapping out 20-25 year non-condensing boiler, which will be 70-75%, the jump in efficiency might still be 0%.

So instead of spending £2k - £5k on a new boiler that will not reduce your fuel bills at all, let alone by £580, spend less than £580 upgrading your existing boiler and heating system for 10-25% energy reduction.

If you have a condensing gas boiler – you will have a condensing model if you have a white plastic pipe underneath – then you will be able to reduce your fuel bills with some zero-cost and low-cost changes to your existing boiler and your heating system. For condensing combi boiler households, you can improve your boiler's efficiency instantly by lowering the flow temperature for heating.

For more efficiency improvements, including for households with a hot water cylinder, we can provide you with a specification bespoke to your boiler that will reduce your fuel bills this winter and send you to an installer that can make those changes. Get in touch.


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