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Why we need to break the gas-boiler cycle, and how.

12 June 2020

  • Energy and sustainability policy
  • Renewable energy

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The way we heat our homes remains one of the biggest challenges to creating a carbon neutral community. The most popular domestic heating system by far is a gas-fired boiler, but these are simply not-compatible with our goals for reduced greenhouse gas emissions, cleaner air and a more sustainable economy. Currently, about 14% of all greenhouse-gas emissions in Surrey come from domestic heating (source).

To better understand the scale of the challenge, compare the 1.2 million gas boilers replaced in England each year with the 75,000 renewable heating systems installed in the last 8 years combined. Clearly, reversing this trend is a difficult task.

What are the gas boiler alternatives?

Heat pumps are most likely to be the closest replacement to gas boilers, though biomass systems may play a secondary role. Heat pumps are powered by electricity, though are so efficient at using this to ‘upgrade’ heat (typically 250-350%), that they are considered renewable. You can read more detail about how they work elsewhere on our website, here.

So what is stopping people from switching?

Most will only think about their heating system when it’s not working, and they need to replace it as soon as possible. In these circumstances, there is a tendency to stick to a familiar technology so that things are resolved quickly and smoothly. This leaves no room to research and consider an alternative system, if they have heard of one in the first place, so the trusted gas boiler remains for another decade or so.

The cost of renewable heat is another major barrier. A simple gas boiler replacement may cost in the region of £2,500, whereas upgrading to a heat pump could cost 3-4x this amount for an air-source system, or up to 8x for a ground-source system. But there is financial support available.

Government financial support for renewable heat

The Renewable Heat Incentive has been supporting these installations for a number of years with guaranteed quarterly payments to the householder, over a 7-year period. These are determined by how heat much your property should need and can total the following amounts:



Rough 7-year RHI payment

(Medium to large house)

Air-source heat pump

£5k - £9.5k

Ground-source heat pump

£15k - £32k


However, the householder still needs to come up with the initial installation costs which can be quite expensive. To combat this, the government are proposing to introduce a ‘Clean Heat Grant’, giving an up-front £4,000 for eligible installations. The details are yet to be decided, though this is likely to be available after the end of the domestic RHI scheme in April 2022.

The grant value is fixed for every installation and is clearly a lot less than most RHI agreements, but this up-front money could make it easier for households to make the switch. 

What about hydrogen, biogas or other options?

Domestic heat pumps are on the market now, and whilst they may be new to some, the technology is well-established and understood. Conversely, the availability of hydrogen and biogas is very low in the UK with most hydrogen projects in the trial phases and more targeted toward large-scale projects. This means heat pumps let us move away from fossil fuel heating today, rather than wait for emerging technologies to be market-ready.

Heat networks are growing rapidly and are perfect for dense areas like town-centres, though most households won't have this option.

A note for Landlords

Landlords who install renewable heating can receive these payments too, which can make worthwhile investments in their properties. Minimum energy efficiency standards exist already for landlords, though it’s possible these will be increased in the future. By upgrading to renewable heat and making use of the grants now, landlords could get ahead of the game and make use of the financial incentives while they exist.

In summary

Renewable heating technologies are available now and are a vital part of the journey to a sustainable Surrey. We urge everybody to think about replacing their gas boilers, so that when the time comes, we make it out of the gas-boiler cycle.

Financial support is available now, though is paid over a 7-year period. From April 2022, up-front grants may be available instead, although the total grant will be significantly less in some cases. But remember, tomorrow’s grant is never guaranteed!

If you want to know more, contact Action Surrey on 0800 783 2503 or email