Electric boilers get suggested as an alternative to gas more and more often. Here's a balanced look at how the two compare on cost, installation and day-to-day use, so you can ask the right questions before deciding.
Gas Safe registered 25 years in the trade 12 years running the business
Written by Chris Gill, C Gill & Son Plumbing & Heating ·
How each one heats your home
A gas boiler burns mains gas to heat water, which circulates through your radiators and, on a combi, straight to your taps. An electric boiler does the same job with a heating element, like a large kettle — no flame, no flue, no combustion at all.
Both can run a normal wet central heating system, so the radiators and pipework in your home don't care which one heats the water. The differences are in what they cost to run, what they need around them, and how much hot water they can deliver.
Running costs: the big difference
Per unit of energy, electricity costs considerably more than gas in the UK. An electric boiler converts almost all of its electricity into heat, but because each unit costs more, heating a whole house electrically usually costs more to run than gas. Homes on economy tariffs, with solar panels, or with very low heat demand can narrow that gap, but for a typical family home on the gas grid, gas is normally cheaper to run.
Installation differences
Electric boilers are simpler to site: no flue, no gas pipe, no condensate drain, and no need for a Gas Safe registered engineer because there's no gas work involved. They do need a suitable electrical supply, and larger models may need your consumer unit and incoming supply checked by an electrician.
A gas boiler needs a flue route, a gas supply of the right size and a condensate drain, and by law it must be fitted by a Gas Safe registered engineer. If your home already has gas, replacing like for like is usually straightforward.
Hot water performance
Gas combi boilers are good at producing hot water on demand at high flow rates. Electric boilers generally heat stored water or deliver lower flow rates, so homes with several bathrooms or high hot water demand often find gas suits them better. For a small flat with one bathroom and modest use, an electric boiler can be perfectly adequate.
Where electric boilers make most sense
Electric boilers tend to come into their own off the gas grid — in homes that would otherwise rely on oil or LPG — or in small, well-insulated properties where the higher running cost stays modest in absolute terms. They're also quiet and compact, with no flue to position, which can matter in flats.
Maintenance and safety
With no combustion, an electric boiler has no flue gases and no carbon monoxide risk from the appliance itself, and there's less to wear out inside. Gas boilers need an annual service to stay safe and efficient, and to keep manufacturer warranty conditions valid. Either way, the heating system around the boiler — radiators, controls, pumps — needs the same care.
Which should you choose?
If your home is on the gas grid and you're replacing an existing gas boiler, gas is usually the practical and economical choice. If you're off the grid, or your property is small with low heat demand, electric is worth a proper look. Our combi vs conventional boiler guide covers the gas options in more detail.
Need it sorted? Book a boiler installation
C Gill & Son installs gas boilers, and Chris will always tell you honestly what suits your home rather than what's easiest to sell. If you're weighing up a replacement, start with our boiler installation page or send the quote form with a note about your current setup.
