Electric Boiler vs Oil Boiler Cost Calculator

How this calculator works

This calculator works in ranges rather than single figures, because real quotes, yields and tariffs genuinely vary that much. It starts from typical UK price, output and savings ranges drawn from published 2026 industry guides and official scheme documentation, then scales them by the quantities you enter and adjusts them for each choice you make below. The result is a low-to-high band that a realistic outcome is likely to fall within, not a promise of the figure you will achieve.

An electric boiler costs to installed against to for oil with its flue and tank considerations in 2026, but the running costs reverse the story emphatically: heating a typical home electrically costs roughly to a year against to on oil, since heating oil delivers heat at 6 to 8 pence per kWh against electricity’s 24.7 to 26.1 pence. Oil’s installation premium repays itself within the first winter or two for any normally heated home.

Home size

Home size scales the installation estimates: larger homes need higher output units, bigger cylinders where fitted and sometimes more pipework, while flats and small houses sit below the three bedroom baseline that published guide prices describe. It does not scale the running cost figures, which follow the demand number you enter instead.

Annual heat demand (kWh)

This is the heat your home needs over a year for space heating and hot water. A typical UK three bedroom house needs roughly 10,000 to 14,000 kWh; if you heat with gas today, your annual gas kWh from your bill multiplied by about 0.85 for boiler efficiency is a good estimate. Every running cost figure on this page scales directly with this number.

Where you live

Heating labour is not priced uniformly across the UK, with published guides putting London and South East installation quotes roughly 15 to 25 percent above the national average. The hardware costs the same everywhere, so the difference sits in engineer day rates, access and parking.

Electricity tariff

The electric boiler’s running cost depends heavily on tariff design: standard rates of 24.7 to 26.1 pence per kWh give the headline figure, while a cylinder-and-storage strategy on off-peak windows cuts the effective rate by a third or more. Oil is priced at typical 2026 delivered rates of roughly 60 to 75 pence per litre through a modern boiler.

What else affects the figures

The comparison both options lose to is the heat pump: for off-grid homes, an air source heat pump heats at roughly a third of the electric boiler’s running cost, undercuts oil in most years on a decent tariff, and carries the Boiler Upgrade Scheme grant for which oil-heated homes squarely qualify, which is why off-grid Britain is where heat pumps are growing fastest. Oil’s remaining case is familiarity and cheap heat while prices behave, tempered by their genuine volatility, tank maintenance and delivery logistics; the electric boiler’s case is the property that can host nothing else, no tank space, no outdoor unit, minimal usage. A holiday let or lightly used cottage genuinely can be cheapest overall with the simple electric box; a family home almost never is.

Certification, planning and grid connection

Electric boilers and heaters need no Gas Safe engineer, but the electrical work is regulated in its own right: new circuits and consumer unit work fall under Part P of the Building Regulations and belong to a qualified electrician who can self-certify through a competent person scheme. High-output electric boilers need supply capacity checking before purchase, occasionally involving the network operator, and any storage-based strategy relies on tariff choice, so confirming Economy 7 or smart tariff availability with your supplier is part of the design rather than an afterthought. Electric heating carries no flue, no condensate and no annual gas safety requirements, one of its genuine conveniences.