Top Electric Boilers by Type and Brand, Plus Whole-Home Control with Drayton Wiser

An electric boiler gives you wet central heating with no gas supply, no flue and no annual gas safety check. It runs your existing radiators, sits quietly on the wall and is 100% efficient at the point of use. The two decisions that matter are which type of boiler suits your hot water and pipework, and how you control it, because an electric boiler that heats every room all day costs far more to run than one that heats only the rooms you are using.

This guide covers both. First we compare every electric boiler brand in the AIZO range across the three types we sell, with our top picks at each output. Then we show how to pair your boiler with the Drayton Wiser smart heating system for room-by-room control of every radiator in the house, and finish with three simpler Drayton thermostats for anyone who just wants reliable time and temperature control.

With electric heating, control is where the savings are. A well-sized boiler with zoned radiators beats a bigger boiler on a single thermostat every time.

Combi, system or heat only: which electric boiler do you need?

All three types heat the water in your radiators. The difference is how you get hot water from the taps, and what kind of pipework you already have.

A quick way to tell what you have: if there are one or two small tanks in the loft feeding the heating, you have an open-vented system, and a heat only boiler is the simplest replacement. If there are no loft tanks and the heating has a pressure gauge and filling loop, it is already sealed, so a system boiler or combi will fit.

Electric combi boilers

A combi heats water as it flows through, so its kW rating decides how much hot water you get. Assuming cold water at 10°C heated to 45°C, a 14kW combi delivers roughly 5.7 litres per minute, which is the practical minimum for one shower. Three-phase models at 18kW to 24kW push that towards 7.4 to 9.8 litres per minute. If hot water matters more than heating output, the Elterm Ensign pairs a modest central heating rating with a 14kW hot water rating, and the Strom AuraHeat stored combis add a 35L integrated cylinder for stronger short bursts from a single-phase supply.

Electric system boilers

A system boiler stores hot water in a separate unvented cylinder, so several taps and showers can run at once without the flow dropping. Pair it with an indirect unvented cylinder if you want the boiler to heat the hot water through a coil, or a direct unvented cylinder with its own immersion heater so the boiler concentrates on the radiators. Single-phase models run up to 14.4kW; above that you need a three-phase supply.

Electric heat only boilers

A heat only (regular) electric boiler is the simplest way to take gas or oil out of an older open-vented system. It works at low, tank-fed pressure, so there is no need to convert the system to sealed, and your existing indirect cylinder keeps heating the hot water through its coil. If that cylinder is an old vented copper tank, consider replacing it with an unvented cylinder at the same time for better hot water pressure.

Every electric boiler brand at AIZO

Each brand has its own strengths, from budget-friendly heat only units to solar-ready and commercial three-phase boilers. Here is what each one does best.

Whole-home control with Drayton Wiser

Most electric boilers arrive with a basic on/off thermostat connection. That means every radiator heats whenever the boiler fires, whether anyone is in the room or not. Drayton Wiser turns your boiler and radiators into a zoned system: the hub decides when the boiler runs, and a smart radiator thermostat on each radiator decides which rooms get the heat. Because electric heating is billed by the kWh, heating only the rooms you use is the single biggest running-cost lever you have.

Which Wiser hub suits your electric boiler?

The hub you need depends on how many things it has to switch: heating only, heating plus hot water, or two heating zones plus hot water.

How Wiser works with your radiators

What makes Wiser a good match for electric boilers

Installation tip: the HubR is a 230V mains-wired control and should be fitted by a competent installer or electrician. Battery devices such as radiator thermostats and room thermostats are simple to fit yourself. Your installer will also confirm the boiler manufacturer's minimum flow or bypass requirements when most radiator valves can close at once.

Simpler Drayton thermostats for electric boilers

Not every home needs room-by-room control. For flats, rentals or anyone who wants dependable time and temperature control without an app ecosystem, these Drayton wireless thermostats are straightforward upgrades that avoid chasing cables into the walls.

Browse more options in our Part L compliant thermostats for electric boilers and the full Drayton Controls range.

Electric boiler and Wiser FAQs

What size electric boiler do I need?

Add up the heat loss of every room using our BTU calculator. For a combi, also check hot water: 14kW is the practical minimum for one shower, and 18kW or more on three phase suits larger homes. If you need several outlets running at once, a system boiler with a cylinder is the better fit.

Can I run an electric boiler on a single-phase supply?

Yes, up to around 14.4kW, provided your consumer unit and main fuse can take the extra load. Higher outputs need a three-phase supply. Your electrician must assess the total connected load before installation.

Does Drayton Wiser work with electric boilers?

Yes. Wiser works with gas, oil, heat pump and electric heating systems. The HubR switches the boiler by relay, or by OpenTherm on 1 and 2 channel hubs where the boiler supports it. Check your boiler's manual for its external control connections before choosing.

Do I need a radiator thermostat on every radiator?

Not on day one. Start with the rooms you use most and add more over time, since Wiser is a buildable system. For full room-by-room control, each room needs its own radiator thermostat or room sensor. Your installer will advise on leaving one radiator or a bypass open where the boiler requires a minimum flow.

Is there a subscription for Wiser?

No. The app, schedules, smart modes and heat reports are all included with no subscription fee.

Can I run an electric boiler from solar panels?

Yes. Solar PV can offset the electricity your boiler uses, and models such as the EHC Comet PV are designed to make the most of surplus generation. See our guide to running an electric boiler with solar panels.