The Off-Grid Heat Pump Revolution: Replacing Oil and LPG

There are approximately 1.5 million homes in the UK that are not connected to the gas grid, according to DESNZ data. These off-grid properties — heated by oil, LPG, or electric storage heaters — represent the fastest-growing segment of UK heat pump adoption. The reason is simple economics: oil costs have been volatile and are trending upwards, LPG is consistently expensive, and the BUS grant of £7,500 makes the switch remarkably affordable. This is the off-grid heat pump revolution, and it is already well underway.

Why Off-Grid Homes Are Switching Fastest

According to MCS installation data, off-grid properties account for approximately 40% of all domestic heat pump installations despite representing only 5-6% of UK housing stock. This massive over-representation tells a clear story: the economics of switching from oil or LPG to a heat pump are significantly better than switching from mains gas.

There are several reasons for this:

• Higher fuel costs — oil and LPG are consistently more expensive per kWh of heat than mains gas, making the savings from a heat pump proportionally larger
• Price volatility — oil prices can spike dramatically (as in 2022), while heat pump electricity costs are more stable and predictable
• No gas grid option — these homes cannot switch to a cheaper gas boiler, so the comparison is always against expensive fuels
• Policy priority — the government has signalled that off-grid homes will be required to switch away from oil and LPG by 2035, making early adoption sensible
• Larger properties — off-grid homes tend to be larger detached properties with more garden space for heat pump units and ground loops

Oil vs Heat Pump: The Economics

Oil heating is inefficient and increasingly expensive. A typical oil boiler operates at 85-90% efficiency, meaning 10-15% of the oil you buy is wasted. By contrast, a heat pump delivers 3-4 units of heat for every unit of electricity consumed — an efficiency of 300-400%.

Source: Energy Saving Trust fuel price data (Q1 2026), Ofgem electricity tariff cap, and MCS installation performance data.

The key insight is that heat pump economics against oil are significantly better than against gas. A homeowner switching from mains gas might save £200-400/year. A homeowner switching from oil saves £800-1,500/year — making the payback period after the BUS grant as short as 3-5 years.

LPG vs Heat Pump: The Economics

LPG (liquefied petroleum gas) is even more expensive than oil in most areas, making the case for switching even stronger. LPG costs approximately 7-10p per kWh of delivered heat, compared to 7-10p for a heat pump — but the heat pump figure is based on a COP of 3.0; at COP 3.5 or higher, the heat pump is significantly cheaper.

LPG users also face the additional burden of tank rental fees (typically £50-100/year) and delivery premiums for remote locations. Eliminating these costs further improves the heat pump business case.

For properties currently using electric storage heaters, the savings are even more dramatic. Storage heaters cost approximately 18-24p per kWh of heat delivered (at the Economy 7 night rate), compared to 7-10p for a heat pump. Savings of £1,500-2,500/year are common for large properties on electric storage heating.

Grants and Funding for Off-Grid Homes

Off-grid homeowners have access to several funding streams that can dramatically reduce the upfront cost of a heat pump.

Source: Government grant programme details, current as of March 2026.

For low-income off-grid households, it is possible to receive a heat pump and insulation at zero cost through the Home Upgrade Grant. Even for households above the income threshold, the BUS grant of £7,500 typically covers 50-75% of the total cost of an air source heat pump installation.

The Electricity Supply Question

One concern unique to off-grid properties is whether the electricity supply is adequate for a heat pump. Rural properties sometimes have limited electrical connections — single-phase supplies with lower capacity than urban homes.

The good news: most domestic heat pumps draw relatively modest amounts of electricity. A typical 8-12kW air source heat pump has an electrical input of 2-4kW — less than an electric shower or kettle. A standard 100A single-phase supply is sufficient for the vast majority of domestic installations.

Properties with older or limited electrical supplies may need an upgrade from their distribution network operator (DNO). This is usually free or low-cost for domestic connections, but can take 4-8 weeks to arrange. Your MCS installer should check your electricity supply capacity during the site survey and arrange any necessary upgrades before installation.

The Solar + Heat Pump Combination

Off-grid properties are often ideal candidates for solar panel installations — they tend to be detached houses with unshaded south-facing roofs. Combining solar panels with a heat pump is one of the most powerful energy saving strategies available.

A typical 4kW solar panel system generates approximately 3,400-4,000 kWh per year of free electricity. A heat pump consuming 3,000-4,000 kWh of electricity per year can therefore run largely on free solar power during daylight hours. Smart controls that prioritise solar electricity for the heat pump can reduce running costs by 30-50%.

Adding a battery (5-10kWh) allows solar electricity to be stored for evening and overnight use, further reducing grid electricity costs. The combined system — heat pump + solar + battery — can reduce heating costs to as little as £200-400/year for a well-insulated property. Compare that to £2,000+ on oil or LPG, and the savings are transformative.

What Happens to Your Oil Tank

Once your heat pump is installed and running, you need to deal with your oil tank. There are three options:

Option 1: Keep It Temporarily

Some homeowners keep the oil tank and boiler as a backup for the first winter. This provides reassurance but is rarely needed — modern heat pumps are reliable and work in all UK temperatures. If you keep the tank, you are still responsible for its condition and insurance implications.

Option 2: Decommission and Remove

The recommended approach. A specialist company will drain any remaining oil, clean the tank, disconnect it, and remove it from your property. Cost: £200-500 depending on tank size and accessibility. This frees up garden space, removes an environmental liability, and eliminates ongoing insurance requirements for oil storage.

Option 3: Repurpose

Some homeowners repurpose old oil tanks as rainwater storage or garden features. Check with your local authority regarding any planning or environmental regulations.

If your tank is underground, decommissioning is more complex and may cost £500-1,500. Underground tanks can be filled with an inert material and left in place, or excavated and removed. Your installer or a specialist tank removal company can advise on the best approach for your situation.

Real Off-Grid Switching Stories

Devon Farmhouse: Oil to Air Source

A 4-bedroom stone farmhouse in Devon replaced a 25-year-old oil boiler with a 14kW Mitsubishi Ecodan. The property had already been insulated with cavity wall and loft insulation. Installation cost after BUS grant: £6,800. Annual heating bill dropped from £2,400 (oil) to £980 (heat pump) — saving £1,420/year. Payback period: 4.8 years. The oil tank was removed, freeing up space for a vegetable garden.

Welsh Cottage: LPG to Ground Source

A 2-bedroom cottage in rural Powys switched from LPG to a 6kW ground source heat pump with horizontal loops in the garden. LPG costs had been £1,800/year. The ground source system runs at a COP of 4.3, with annual heating costs of £420. Combined with 3kW of solar panels, the total annual energy cost for heating and hot water is under £250. Installation cost after BUS grant: £12,500.

Scottish Highlands: Oil to Air Source + Solar

A well-insulated 3-bedroom bungalow in the Highlands replaced oil heating with a 10kW Vaillant aroTHERM plus a 5kW solar panel system. Despite colder temperatures (average winter low of -4°C), the heat pump achieves a seasonal COP of 2.9. Annual heating costs: £750 (versus £2,100 on oil). With solar generating approximately 4,200 kWh/year, the effective heating cost drops to around £500.

Challenges Specific to Off-Grid Properties

Installer Availability

Remote rural properties can struggle to find MCS-certified installers willing to travel. Installer shortages are worst in Wales, the Scottish Highlands, and parts of southwest England. Getting multiple quotes may require casting a wider geographical net.

Electrical Supply Upgrades

As discussed above, some rural properties need electrical supply upgrades. This is usually straightforward but can delay installation by several weeks.

Older Building Fabric

Many off-grid properties are older, solid-wall constructions that need insulation improvements before a heat pump will work efficiently. The cost of insulation can be substantial — but the long-term savings and improved comfort make it worthwhile. The Home Upgrade Grant can cover insulation costs for eligible households.

Property Size

Off-grid homes tend to be larger than average, requiring bigger (and more expensive) heat pump systems. A 4-5 bedroom detached farmhouse may need a 16-20kW system, costing £2,000-4,000 more than a typical 8-12kW domestic unit. The BUS grant of £7,500 still applies regardless of system size.

Frequently Asked Questions

How much can I save switching from oil?

Typical savings are £800-1,500/year for a 3-bedroom detached home. The exact figure depends on your current oil consumption, oil prices, and the efficiency of your new heat pump system.

Can I get the BUS grant for replacing oil or LPG?

Yes. The BUS grant of £7,500 is available for replacing any fossil fuel heating system including oil and LPG. You must use an MCS-certified installer.

Do heat pumps work in remote rural locations?

Yes. Air source heat pumps work anywhere in the UK. You need a standard electrical supply — which your installer should verify during the site survey.

What happens to my oil tank?

It can be decommissioned and removed for £200-500. Some homeowners keep it temporarily as backup, but most remove it once confident in their heat pump.

Is the electricity supply strong enough?

Usually yes. A typical heat pump draws 2-4kW of electricity — less than an electric shower. If your supply needs upgrading, your installer can arrange this.

Can I combine a heat pump with solar panels?

Absolutely. Solar panels can generate the electricity your heat pump needs, reducing running costs by 30-50%. This is one of the most effective energy-saving combinations available.