BOILERS GUIDE
Central Heating System 2026: Grants & Upgrade Options
If your central heating system is old, inefficient, or broken, you could get it replaced for free under ECO4 or heavily subsidised through the Boiler Upgrade Scheme.
If your central heating system is old, inefficient, or broken, you could get it replaced for free under ECO4 or heavily subsidised through the Boiler Upgrade Scheme.
Answer a few quick questions to see which government energy grants you're eligible for. Free, instant results.
If your central heating system is old, inefficient, or broken, you could get it replaced for free under ECO4 or heavily subsidised through the Boiler Upgrade Scheme. ECO4 covers the full cost for eligible low-income households, while BUS knocks £7,500 off a heat pump installation. Your options depend on what you currently have, your EPC rating, and your household income.
This matters more than most people realise. The grants available to you, the upgrade path that makes sense, and the cost you'll face all depend on what's currently heating your home.
Most UK homes run on a gas boiler connected to radiators via a wet central heating system. If that's you, your boiler heats water, pumps it through pipes to your radiators, and the radiators warm your rooms. Simple enough. But around 4 million homes don't have mains gas at all, and they're running on oil, LPG, electric storage heaters, or in some older properties, solid fuel systems like coal or wood.
Here's why this matters for grants: homes without mains gas are prioritised by almost every funding scheme. If you're on oil or LPG, you're actually in a stronger position for a funded heat pump than someone with a relatively modern gas combi boiler.
So what's your system? Roughly:
If you're not sure, check your EPC. It lists your heating system type. And if you don't have a current EPC, here's what one costs and why it's worth getting before you apply for anything.
Right, this is what you're here for.
Two schemes are doing the heavy lifting for central heating upgrades right now. They work very differently, cover different people, and can't be combined on the same measure, so let's be clear about which one applies to you.
ECO4 is the one that can fund your entire central heating system at no cost to you. It's open until December 2026 and targets low-income households in poorly insulated homes. If you receive benefits like Universal Credit, Pension Credit, Child Tax Credit, or Income-based JSA, and your home has an EPC of D or below, you're likely eligible.
The scheme doesn't just cover boiler replacements. It funds first-time central heating installations (if you've never had a proper system), heat pumps, insulation, and sometimes a combination. We've covered the full eligibility criteria in our free boiler scheme guide, which walks through exactly who qualifies and how to apply.
One thing most guides won't tell you: ECO4 is delivered by energy suppliers, and each supplier has different priorities. Some are actively funding first-time central heating in rural homes. Others are focused on insulation. The installer you go through matters enormously because they determine which supplier's obligation they fulfil.
This one's simpler but narrower. BUS gives you a flat £7,500 off an air source heat pump or ground source heat pump, £5,000 off a biomass boiler, or £2,500 off an air-to-air heat pump or heat battery. It's open until 2030 under the Warm Homes Plan.
No income test. No benefits requirement. But you do need a valid EPC with no outstanding loft or cavity wall insulation recommendations, and the property must not currently be on the gas grid if you're claiming for biomass. For heat pumps, gas-connected homes are eligible.
The catch? Even with £7,500 off, you're still paying £4,000 to £7,000 out of pocket for a typical air source heat pump installation. That's not nothing. We'll get into the full cost breakdown below.
This varies wildly by council area. Some local authorities are offering funded heating upgrades, others are focused entirely on insulation. The scheme runs until 2030 under the Warm Homes Plan and the amounts depend on where you live and what your local authority has decided to prioritise. Check your council's website or read our full guide to the Warm Homes: Local Grant for how to find your area's specific offer.
£2,500 to £15,000. That's the honest range, and it's wide because "central heating system" covers everything from swapping a boiler to ripping out storage heaters and installing a complete wet system from scratch.
Here's what we typically see:
| Upgrade type | Typical cost (2026) | Notes |
|---|---|---|
| Gas boiler replacement (like-for-like) | £2,500–£4,500 | Combi swap, existing pipework |
| Gas boiler + new radiators | £4,000–£7,000 | Older systems needing full refresh |
| First-time central heating (no existing system) | £5,000–£9,000 | Pipework, radiators, boiler, controls |
| Air source heat pump | £11,000–£15,000 | Before BUS grant |
| Ground source heat pump | £20,000–£35,000 | Before BUS grant |
| Biomass boiler | £10,000–£19,000 | Before BUS grant |
Those heat pump figures look alarming. But after the £7,500 BUS grant, an air source heat pump comes in at £4,000 to £7,500, which isn't dramatically more than a full gas system replacement with new radiators. And if you're on oil or LPG, the running cost savings close the gap within 5-7 years in most cases.
For ground source heat pumps specifically, our detailed guide covers costs and whether the higher upfront spend is justified.
Honestly, this one depends on your situation and we can't give you a straight answer without knowing your home. But here's how we'd think about it.
Stick with gas if:
Go for a heat pump if:
Here's the honest bit. A heat pump in a draughty, uninsulated Victorian terrace will struggle. It'll run constantly, your bills won't drop, and you'll be cold. But a heat pump in a well-insulated 1990s semi? That's a different story entirely. The insulation comes first. Always.
If you're weighing this decision, our guide on whether heat pumps are worth it runs through the real numbers based on different house types and fuel costs.
One tangent worth mentioning: hybrid systems exist. A heat pump handles most of your heating, and a gas boiler kicks in on the coldest days. They're not covered by BUS (the grant requires a full fossil fuel replacement), but some ECO4 installations have included them. Anyway.
Two routes. Both start with your EPC.
If you don't have one, get one. They cost £60 to £120 and take about 45 minutes. Your EPC rating determines which schemes you can access. A D rating or below opens up ECO4. Any rating works for BUS, provided you've addressed any recommended loft or cavity insulation. Here's what each EPC band means for grants.
For ECO4, you need to be receiving a qualifying benefit AND have a home rated D, E, F, or G. The process goes through an installer who handles the application to the energy supplier. You don't apply to a government website directly.
For BUS, you need an MCS-certified installer to submit the application on your behalf. They apply for the voucher, and the £7,500 (or £5,000 for biomass) comes off your invoice. You never see the grant money yourself.
The simplest first step? Check your eligibility through our tool. Two minutes, no commitment, and you'll see exactly which schemes apply to your home.
So you've got a new system. Now what?
If you've had a heat pump installed, your heating habits need to change. Heat pumps work best running at a lower temperature for longer periods, not the blast-it-for-an-hour approach that works with gas boilers. Set your flow temperature to around 35-45°C (your installer should configure this) and let the system maintain a steady warmth rather than cycling on and off.
Insulation amplifies everything. Even after a new system goes in, adding loft insulation or addressing wall insulation makes your new heating work less hard, which means lower bills and a longer system lifespan.
Three quick wins that cost nothing:
And look, if your walls and loft are already sorted, consider whether your windows are the weak link. Our guide to window grants covers what funding exists for glazing upgrades in 2026.
The system is only half the equation. The fabric of your home determines whether that heat stays inside or leaks straight out through the walls and roof. Get the envelope right, and even a modest heating system keeps you comfortable.
Common questions