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Q&As
What are the eco options for replacing a combi boiler?
I have a 12-year-old combi boiler and the company servicing it has highlighted a number of parts that are no longer available to replace. i.e. if one of these parts break it will be the end of boiler and an emergency job to replace it.
Thus I am thinking that now is the time to do a considered (planned) replacement before a crisis develops. I am in a mid-terrace house with ground, 1st and 2nd floors. The main roof basically faces East – West, thus getting the sun in the morning, mid-afternoon, through to Sunset, precise timings being season dependent.
I am looking for green and energy efficient ideas and the companies to supply them. The only 2 things I will rule out are underfloor heating (am not prepared to tear up the floors; bathroom already has electric UFH) and wind energy (a mast would not be popular or practical).
Your thoughts please
Answers
It’s certainly sensible to consider replacement if your boiler is no longer serviceable, and it’s great that you’re looking at ‘green’ heating options. You might want to check out our dedicated advice on renewables at https://www.self-build.co.uk/renewables
One thing I would say is that if you’re 100% set on ruling out underfloor heating, you’re really limiting your options. Water-based UFH operates at the perfect flow temperature to match up with various forms of renewable heating systems (such as air source heat pumps and ground source heat pumps). Try teaming this kind of system with radiators – even the oversized/low temp types – and the efficiency of the heat pump is likely to drop considerably. As a result, the tech will often prove more expensive to run than a modern gas boiler.
So in your situation, a top-of-the-range gas boiler sounds like the best option (I’m presuming that’s the fuel source you’re using at the moment). These days, they’re all 88%+ efficient.
The Energy Saving Trust reckons you can save around £130 per year in a mid-terrace house if you’re replacing a D-rated boiler, rising to around £275 per year if you’re swapping out a G-rated model. If you’re putting the new boiler in the same position as the old with minimal new pipework, you’ll probably be looking at around £500-£1,000 for the installation work (in addition to the cost of the new boiler).
Your question implies you’re also considering solar thermal panels. While a south-facing orientation is preferable, as a rule west-facing is often still viable (probably suffering a performance dip of around 10%-20% compared to a southerly aspect) and generally better than east-facing. North-facing is the real no-no.
The domestic Renewable Heat Incentive is set to launch this spring, and will offer payouts on solar thermal (provided they’re only used for hot water), so there’s the potential to earn cashback on qualifying installations. For more on this check out https://www.self-build.co.uk/renewable-heat-incentive-tariffs-set
