The best electric water heating systems in the UK use modern thermal batteries, and are compact, instantaneous heating systems. Unlike traditional cylinders, thermal battery systems such as Fischer Aquafficient store heat energy rather than large volumes of hot water, helping reduce standing heat loss, reclaim space, and remove annual cylinder maintenance.
What is electric water heating?
Electric water heating is any system that uses electricity to heat the water used by your taps, showers, baths, and kitchen appliances. Gas boilers rely on a burner, which is essentially a naked flame that in turn heats water as it runs through your boiler. Whereas electric water heating stores heat to provide hot water, which can be used on demand.
For homeowners thinking of moving away from gas, if you remove your gas boiler and replace your heating with electric radiators, you still need a reliable way to heat your water. That could mean choosing an electric boiler and an instantaneous water heater like Fischer’s Aquafficient.
Some electric water heating systems rely on air as their fuel source, working in a similar way to an air source heat pump. These systems usually have an electric heating element built in as a backup, just in case the air temperature around the unit is too low.
A key benefit of switching to an electric water heater
One of the biggest benefits of switching fully to electric is that you may be able to cap your gas line and remove the daily gas standing charge entirely.
With the April 2026 electricity price cap at 24.67p/kWh, running costs still depend heavily on how much energy your system uses — but removing unused gas standing charges can make the transition more practical for homes moving away from using fossil fuels to power their home.
What is the most efficient electric water heater in the UK?
The most efficient electric water heater is not always the one with the lowest wattage. It’s a system that reduces wasted energy while still delivering enough hot water for your household. It’s a system that reduces wasted energy while still delivering enough hot water for your household. Pinpointing the most efficient electric water heater UK wide requires looking at how a system minimizes systemic background losses rather than just focusing on pure power draw metrics.
Traditional electric storage cylinders heat and store a tank of water, often keeping it hot for long periods even when no one is using it. This creates standby heat loss, where heat slowly escapes from the cylinder into the surrounding cupboard or room. In simple terms, you can end up paying more to keep water hot just in case you need it later.
However, electric water heaters built with modern thermal batteries work differently. Fischer’s Aquafficient stores heat energy inside a Phase Change Material (PCM). So rather than storing a large tank of hot water, when you turn on the tap, cold water passes through the unit and is heated using the stored thermal energy instead.
Since you no longer have to rely on a water tank to store (much needed) hot H2O, it means households produce less waste as:
- An electric water heater stores heat, rather than litres of hot water
- The modern system avoids keeping a full cylinder hot all day
- Households gain hot water on demand – no need to keep the hot water tank full in case you need a bath!
- Electric water heaters require no annual cylinder safety checks
- Homes also gain extra storage space, since electric water heaters take up far less space – perfect for those who love a clever renovation project
Choosing the right size electric water heater for your home
Choosing the right size electric water heater depends on the size of your property, how many bathrooms you have, and how much hot water your household uses at peak times.
Whether you live in a flat or family home with multiple bathrooms, we’ve created a helpful summary to indicate which type of electric water heater your home would benefit from.
| Property type | Typical hot water usage | Recommended option |
|---|---|---|
| Small flat / one bathroom | Hot water for taps, showers, or households with limited daily use | Instantaneous water heater |
| Family home / multiple bathrooms | Higher hot water demand across baths, showers, and kitchen use | Larger Aquafficient unit — a 150L thermal battery can replace a standard 250L hot water cylinder in around half the space |
| Landlord properties / portfolios | Compliance upgrades targeting energy efficiency improvements and EPC targets ahead of legal mandates | Space-saving Aquafficient or Aquafficient Eco+ unit to reduce standby heat loss and remove annual cylinder safety checks |
For smaller homes and apartments, space is often just as important as hot water performance. A bulky cylinder can take over precious space in an airing cupboard, while a compact electric water heating system can free up valuable storage for towels and toiletries to be kept.
The different types of electric water heating
As well as traditional gas setups, finding the best electric hot water cylinder alternative means looking beyond systems that simply heat water and store it in a large tank. Today, there are plenty of highly efficient electric water heating options available, all with their own unique benefits.
Aquafficient thermal battery
One efficient replacement for your existing hot water system is Fischer’s Aquafficient. The Aquafficient is an innovative, modern and highly efficient electric solution to heating water.
The instant electric water heater from Fischer uses a single heating element, and patented thermal storage technology, to provide instant hot water without the need for tanks. Instead, the hot water is produced from stored heat energy within a unique phase change material.
The Aquafficient benefits from minimal maintenance, is supplied with a 10-year warranty and is half the height of the equivalent cylinder on average, reclaiming valuable space in your home. With no controls to worry about, Aquafficient is simply fit and forget.
If you’re looking for the best electric water heater and to make the switch from a gas powered home, the Aquafficient is especially useful for:
- Efficient renovation projects
- Households living in a flat
- Homes replacing gas boilers to reduce their reliance on fossil fuels
- Properties with limited cupboard space
- Homeowners who want lower maintenance
Aquafficient Eco+
If Aquafficient isn’t the product for you, Aquafficient Eco+ is another great alternative. Aquafficient Eco+ is an air source water heater, designed to provide hot water to your home quickly and efficiently. Using air as its main energy source; the Aquafficient Eco+ is an efficient and renewable energy product that provides heated water without excessive energy needs or bulky water tanks.
Aquafficient Eco+ also benefits homeowners from a low maintenance requirement as well, and has a visible temperature monitor on the front of the unit.
Fischer electric duo boilers
For homeowners wanting to remove a gas or oil boiler but still need central heating and hot water, Fischer electric duo boilers are the natural progression. The system provides hot water on demand without the need for any external tanks or cylinders.
With a 10-year warranty and a smart wireless thermostat to control your heating, Fischer Electric Boilers are a modern, cleaner alternative to the gas and oil boilers of the past. They can supply hot water on demand without external tanks or cylinders, while also supporting a wet heating system. For more information, learn more about the best electric boiler alternatives for hot water only.
Electric Water Heating FAQs
Is it easy to replace a gas water heater with an electric water heater?
Yes, it is easy to replace a gas water heater with an electric water heater, but it is usually a replacement rather than a simple conversion.
A qualified professional will need to safely disconnect and cap the gas supply, remove the flue if required, and install the new electric water heating system. Systems such as Aquafficient are easier long-term because they do not need discharge pipes, do not store hot water, and require zero annual cylinder safety checks.
Is it worth changing from gas to electric hot water?
For many homes, yes, it’s worth changing from gas to electric hot water. Moving to electric hot water can help reduce reliance on fossil fuels, future-proof the property, and remove the daily gas standing charge if the home becomes fully electric.
It can be especially worthwhile for renovators, landlords, and homeowners already planning to replace an ageing gas boiler in anticipation of updates to the Future Homes Standard. This upgrade is particularly vital for private rental property managers who must align their properties with the expanded January 2026 Decent Homes Standard criteria while moving toward the EPC Band C 2030 mandate.
What is the downside of an electric water heater?
The main downside of older electric water heaters is that traditional storage tanks can suffer from standby heat loss and slower recovery times. This means energy can be wasted keeping water hot when it is not being used.
However, modern thermal batteries used in new electric hot water systems like the Aquafficient help overcome this by storing heat energy directly and delivering hot water on demand.
What is the most efficient type of electric water heater?
For many UK homes, one of the most efficient options is a thermal battery system. Instead of storing a large tank of hot water, it stores heat inside a Phase Change Material and transfers that heat to mains water when needed. This helps reduce standing heat loss and removes the need to reheat a full cylinder for small hot water tasks.
Get your free catalogue today
If you are replacing an old gas boiler, renovating a smaller home, or looking for a lower-maintenance hot water system, Fischer can help you choose the right electric water heating solution for your property.
Get your free catalogue today and find out more about how Fischer can help you change your home to an electric heating system in the future.