What is an electric boiler and how does it work?
An electric boiler heats water using electric heating elements instead of burning gas or oil. It supplies hot water for both central heating and domestic hot water applications, powering radiators, underfloor heating systems, or hot water cylinders. These boilers are compact, quiet, highly efficient—offering nearly 100% energy conversion—and produce no on-site emissions, making them a clean heating solution.
What are the main types of electric boilers?
There are three common types of electric boilers, each suited to different home heating needs:
- Electric Combi Boilers: These compact, all-in-one units provide both central heating and instant hot water on demand without the need for a separate hot water cylinder. They are ideal for smaller properties or flats where space is limited.
- Electric System Boilers: System boilers include internal components like the pump and expansion vessels, but require a separate hot water cylinder for storage. They offer consistent hot water supply and are suitable for medium to large homes with higher hot water demand.
- Flow (Heat-only) Electric Boilers: Sometimes called heat-only boilers, these heat water which is then stored in a hot water cylinder. They need both a hot water cylinder and a cold water storage tank. These are best suited to larger properties with multiple bathrooms or higher simultaneous hot water usage.
What sizes of electric boilers are available and how do I choose the right one?
Electric boilers come in a variety of sizes, typically from 4.5 kW up to 24 kW or more. The correct size depends on your home's heating requirements, insulation quality, number of radiators, and domestic hot water needs. Generally, smaller boilers suit flats or small houses, while larger models are better for big homes or commercial spaces. It is important to consult a heating professional to calculate the correct boiler capacity to ensure comfort and energy efficiency.
How do I choose the right type of electric boiler for my home?
Choosing between combi, system, and flow electric boilers depends on your property's size, hot water requirements, and space availability:
- Small properties: Electric combi boilers are compact and ideal where space is limited and hot water demand is moderate.
- Larger homes: System or flow boilers with hot water cylinders offer better performance for multiple bathrooms or high water usage.
- Space considerations: Combi boilers do not need external storage tanks, making them suitable for flats and small homes.
Consulting a heating professional for heat loss calculations and system design ensures correct boiler selection for maximum efficiency.
When should I consider using a hot water cylinder with an electric boiler, and what sizes are available?
Hot water cylinders store heated water for domestic use, ensuring a steady supply for baths, showers, and multiple simultaneous outlets. They are commonly used alongside system electric boilers or where instantaneous hot water supply from a combi boiler is insufficient. Cylinder sizes range from 100 to 300 litres and more, with smaller cylinders suitable for one or two occupants, and larger capacities serving bigger households or properties with multiple bathrooms. Using an appropriately sized cylinder helps prevent running out of hot water and saves energy.
What is the function and importance of the pump in an electric boiler system?
The pump circulates heated water from the electric boiler through your central heating system or underfloor heating loops. It ensures that hot water flows efficiently through radiators, pipes, or UFH circuits to evenly distribute heat throughout the home. A properly functioning pump is essential for system performance, energy efficiency, and maintaining consistent heating levels. Without effective circulation, hot water would not reach all parts of the property, leading to cold spots and inefficient energy use.
What are potable and heating expansion vessels, and when are they needed?
Expansion vessels accommodate the natural expansion of water within a sealed heating or hot water system as it heats up. Heating expansion vessels are installed on the heating circuit to control pressure changes in radiators or underfloor heating loops. Potable or domestic expansion vessels are used on the hot water circuit, especially when a cylinder is involved, maintaining water safety and system pressure. Correct sizing and installation of expansion vessels protect your system from damage and help maintain efficient operation.
Can electric boilers be used with underfloor heating?
Yes, electric boilers work well with both traditional radiators and underfloor heating. Many system and flow boilers integrate easily with UFH systems because they provide water at suitable low temperatures. This flexibility allows homeowners to combine different heating types for improved comfort and efficiency.
Can electric boilers be used with both underfloor heating and central heating?
Yes, electric boilers are compatible with both water-based underfloor heating and traditional radiator systems. They supply water at suitable temperatures that can be managed separately for each type of heating system. Many modern electric boilers or pre-plumbed boiler packages enable integration of both heating methods for maximum comfort and efficiency. This flexibility allows homeowners to benefit from the even warmth of underfloor heating while maintaining the quicker response of radiators.
Can electric boilers be installed with solar PV systems?
Electric boilers can work seamlessly with solar photovoltaic (PV) systems, enabling you to use your own renewable electricity to heat your home. Some models, such as the EHC Comet PV Electric System Boiler 14.4 kW, are specifically designed for solar integration to optimize energy use and lower electricity bills by prioritizing solar power before drawing electricity from the grid.
Are there popular electric boiler packages available?
Complete pre-plumbed boiler packages, including the boiler, cylinder, controls, and fittings, are available for easier installation and compatibility assurance. These packages are designed for both underfloor and radiator heating systems, simplifying setup and reducing installation time. Explore the options on our Boiler Packages and Pre-Plumbed Solutions page.
What is warm air heating and can it be used with electric boilers?
Warm air heating systems distribute heated air through ducts and vents to warm rooms quickly and evenly. Although less common than water-based systems, warm air heating can be powered by electric boilers in certain setups. For more details on warm air systems and their compatibility, please see our Warm Air Heating Collection.
Are there government grants or subsidies available for electric boiler installations?
Yes, there are UK government and local schemes aimed at encouraging low-carbon heating technologies, including electric boilers. While many grants focus on heat pumps, there are incentives and funding opportunities that may apply to electric heating solutions, especially where they incorporate renewable energy. For the latest information on grants and subsidies, please visit our detailed guide: UK Energy Subsidies and Grants – FAQ.
Do you offer complete electric boiler packages?
Yes, we provide ready-to-install boiler packages that include the electric boiler, hot water cylinder, controls, and all necessary fittings. These packages are designed for quick and efficient installation, compatible with both underfloor heating and radiator systems. View our full range at: Boiler Packages and Pre-Plumbed Solutions.
What are the benefits of installing an electric boiler?
Electric boilers offer several advantages including:
- High efficiency with nearly 100% energy conversion.
- Zero on-site emissions supporting environmental goals.
- Compact size and flexible installation options without need for flues or gas connections.
- Low maintenance requirements compared to combustion boilers.
- Compatibility with renewable energy sources such as solar PV.
- Quiet operation, ideal for apartments and small properties.
What brands and products do you supply?
We stock reputable electric boilers and heating solutions from well-known UK manufacturers and brands. Browse our selections and discover electric boilers, cylinders, and compatible accessories tailored for efficiency and reliability at Aizo Quality Heating Boilers.
