Electric Shower vs Combi Boiler: Full Overview

aiden weeks

Aiden Weeks

Last Updated: 20/04/2024

Are you torn between choosing an electric shower or a combi boiler for your home?

Deciding on the best water heating solution can feel like navigating a maze of technical details and conflicting advice. 

Imagine enjoying a warm, comforting shower at the end of a long day—with the right choice, this could be your reality. 

However, the plethora of options available might leave you needing clarification. 

This article serves as your guide through the maze, offering a clear path from confusion to clarity.

We’ll explore the nuances of electric showers and combi boilers, helping you understand which fits your needs and lifestyle perfectly. 

Whether renovating your home or upgrading your bathroom, making an informed decision will ensure you enjoy cost-effective and efficient showering experiences for years.

Key Takeaways

  • Understanding the Basics: An electric shower heats water on demand using electricity, which means it does not rely on your home’s boiler system. In contrast, a combi boiler provides hot water directly from the mains without needing a storage tank, efficiently serving central heating and hot water needs.

  • Best Choice for Different Needs: If you have a smaller home or need a solution that can offer hot water independently of your central heating system, an electric shower might be the ideal choice. However, a combi boiler is generally more suitable for larger homes or those looking for a more integrated solution that provides heating and hot water.

  • Efficiency and Cost: Electric showers are generally cheaper to install and are independent of the home heating system, making them a good option for immediate hot water needs without additional heating costs. While initially more expensive to install, Combi boilers can be more cost-effective in the long run due to their higher efficiency and dual-functionality.

  • Deciding Factor: When choosing between an electric shower and a combi boiler, consider factors such as your household’s water usage, the size of your home, and existing heating systems. Electric showers provide hot water on demand directly from the cold water supply, which is ideal for instant use. In contrast, combi boilers efficiently heat water and your home, best suited for continuous usage and larger spaces.

  • Find out the top rated electric showers in 2024 from Best Electric Showers.

Free PDF: Ultimate Buyer's Guide to Electric Showers

What is an Electric Shower?

An electric shower is a type of shower that heats water on demand directly at the point of use. 

Unlike traditional showers that draw hot water from a boiler or hot water tank, electric showers only require a cold water supply. 

As you turn the shower on, the water passes through a heating element within the unit. By adjusting the settings, you can control the temperature of the water instantly heated and delivered through the shower head.

Key Features of Electric Showers

  • Independent Heating: Electric showers are independent of your home's central heating system. This means they are not affected by hot water usage elsewhere in your home, ensuring you can always have a hot shower, even if your boiler is off or malfunctioning.

  • Temperature Control: They typically include a dial or digital controls that allow you to adjust the temperature to your preference. This feature ensures that the water temperature is consistent and can be easily modified for comfort.

  • Energy Efficiency: Electric showers can be more energy-efficient for households that do not require large volumes of hot water throughout the day by heating only the water used. They are particularly beneficial in reducing water heating costs as they eliminate the need to heat a full tank.

  • Ease of Installation: Electric showers are generally easier and less expensive than other showers because they do not require a connection to a hot water supply. This makes them ideal for new bathrooms or upgrades in areas where accessing hot water plumbing would be challenging or costly.

These key features make electric showers a popular choice for many households. They provide a reliable and efficient solution for enjoying a warm shower anytime, without the constraints of your home’s central heating system.

What is a Combi Boiler?

A combi (combination) boiler is a high-efficiency water heater and a central heating boiler combined within one compact unit. 

Therefore, no separate hot water cylinder is necessary, offering space saving within the property. 

Combi boilers heat water directly from the mains when you turn on a tap so that you won’t need a hot water storage cylinder or a cold water storage tank in the roof space.

Key Features of Combi Boilers

  • Space-Saving: One of the most significant advantages of a combi boiler is its size. The unit is compact and doesn’t require additional space for a hot water cylinder, making it ideal for smaller homes and apartments where space is at a premium.

  • Instant Hot Water Supply: Combi boilers provide hot water on demand with high efficiency. This means hot water is delivered at mains pressure, making for a powerful and satisfying shower without needing an additional pump.

  • Energy Efficiency: Because combi boilers only heat your water, they are typically more energy-efficient than systems that store hot water. This can lead to lower energy bills and a reduced carbon footprint.

  • Simplified Installation: The installation process for a combi boiler is usually simpler than that required for conventional systems because there are fewer components. This often translates into lower installation costs and less disruption during setup.

Combi boilers are excellent for homes with limited space and moderate hot water needs. 

By combining the necessity for both a water heater and a central heating boiler into a single unit, these boilers provide a practical, efficient, and cost-effective solution for heating your home and water.

Comparison of Electric Shower and Combi Boiler

Water Heating Efficiency

Electric showers and combi boilers serve distinct purposes regarding water heating efficiency. 

Electric showers heat water instantly at the point of use, ensuring that no heat is lost in transit from a boiler to your shower. 

This can be particularly advantageous in homes with a bathroom far from the boiler. 

On the other hand, Combi boilers heat water directly from the mains and deliver it to taps and showers at mains pressure, which can be more efficient for overall home heating and maintaining consistent water temperature during use.


Electric showers are generally less expensive to install than combi boilers due to their simpler setup and lack of extensive pipework. 

Electric showers' operating costs can vary depending on the price of electricity, but they only consume energy when in use. 

While more expensive initially, combi boilers may lead to lower overall energy costs in the long run due to their higher efficiency, especially in homes that use significant amounts of hot water.

Installation and Maintenance Requirements

Electric showers are straightforward to install, often only requiring a connection to the cold water supply and electrical system. 

They are also easier to maintain, with fewer moving parts and no dependency on a central heating system. 

Combi boilers require a more complex installation involving gas lines and flue systems. Regular maintenance is needed to ensure efficient operation and prevent breakdowns.

Space Considerations

Electric showers offer a clear advantage for smaller homes or apartments with limited space, as they do not require space for a cylinder or boiler. 

While compact compared to traditional boiler systems, Combi boilers still require space for the unit and may only be suitable for a small space.

Suitability for Different Household Sizes

Electric showers are ideal for households with lower hot water demand or sporadic hot water usage. 

They ensure that hot water is always available but are limited by the flow rate of the electric heater. 

Combi boilers are better suited for larger households with higher hot water needs. They efficiently provide hot water and central heating without needing a separate water tank.

Pros and Cons of Electric Showers

Advantages of Choosing an Electric Shower

  • Instant Hot Water: One of the most significant advantages of electric showers is their ability to provide hot water instantly. There’s no waiting time for the water to heat up, which is especially convenient during busy mornings or when multiple people need to use the shower back-to-back.
  • Energy Efficiency: Electric showers heat water on demand, which means they only use energy when the shower is in use. This can lower energy consumption than heating a hot water tank, potentially reducing electricity bills.
  • Easy Installation and Maintenance: Electric showers are relatively easy to install as they do not require a connection to a hot water supply, just a cold water pipe and an electrical connection. They also tend to have fewer mechanical issues than boiler systems, making maintenance simpler and less frequent.

Potential Drawbacks

  • Dependence on Water Pressure: An electric shower's performance heavily depends on the main water pressure in your home. If the water pressure is low, the shower may not function effectively, leading to a less satisfying shower experience.
  • Limited Water Flow: Electric showers provide instant hot water, so the flow rate is often lower than those connected to a combi boiler. This can result in a less powerful shower that some users may need help finding.
  • Temperature Variability: Electric showers can sometimes struggle to maintain a consistent water temperature, particularly if other water fixtures in the home are used simultaneously. This can lead to sudden temperature fluctuations during use.

Pros and Cons of Combi Boilers

Benefits of Installing a Combi Boiler

  • Efficient Hot Water Supply: Combi boilers are highly efficient. They heat water directly from the mains when needed, meaning there is no energy waste when heating a water tank. This system ensures an efficient hot water supply, lowering energy bills.
  • Space Saving: Combi boilers do not require a separate hot water tank, so they save significant space in the home. This makes them ideal for smaller houses or apartments where space is at a premium.
  • Simplified Installation and Servicing: Combi boilers tend to have fewer components than traditional heating systems, which makes installation quicker and servicing simpler. This can reduce installation and maintenance costs over the lifespan of the boiler.
  • Consistent Water Pressure: As long as the mains pressure is adequate, combi boilers can deliver hot water at high pressure, perfect for a refreshing and powerful shower experience.

Possible Disadvantages

  • Dependence on Mains Pressure: A combi boiler's performance heavily depends on the mains water pressure. If the pressure is too low, it may not function properly, which can be a significant disadvantage for homes in areas with low water pressure.
  • Limited Hot Water for Multiple Uses: While combi boilers are efficient, they might need help to supply sufficient hot water simultaneously to multiple outlets (like showers and taps). This can be a drawback in larger households with higher hot water needs.

Although combi boilers are generally more cost-effective in the long run due to their energy efficiency, the initial installation cost can be higher than that of traditional systems. Homeowners need to consider this upfront investment.

Cost Comparison

Initial Setup and Installation Costs

The initial cost of installing an electric shower is generally lower than installing a combi boiler. 

Electric showers require minimal changes to plumbing and electrical systems, typically involving only the installation of the unit and a connection to the existing water and electrical supply. 

This simplicity can significantly reduce the upfront costs, making electric showers an attractive option for those on a tight budget or needing a quick solution.

In contrast, combi boilers involve a more complex installation process, often requiring modifications to the home’s central heating system, new pipework, and sometimes the removal of old water tanks or boilers. 

This can lead to higher labour and material costs, but the long-term benefits of such an investment must be considered.

Long-Term Running Costs

While the initial setup cost for electric showers is lower, their long-term running costs can vary. 

Electric showers use a significant amount of electricity, and their cost-effectiveness depends on the electricity rates and the frequency of use. 

However, they are only used when needed, which can mitigate some running costs compared to systems that maintain a constant hot water supply.

Though more expensive to install, combi boilers typically offer better long-term savings. 

They are more efficient as they heat water directly from the mains without storing and heating it. 

This efficiency can reduce gas bills, especially in homes where hot water is used frequently. 

Additionally, combi boilers are known for their longevity and reliability, which can further enhance their cost-effectiveness over time.

Environmental Impact

Energy Efficiency and Carbon Footprint Comparison

Electric showers and combi boilers have distinct environmental impacts, primarily through their energy consumption patterns and resulting carbon footprints.

Electric Showers

Electric showers are energy efficient because they heat water directly at the point of use, ensuring no heat is wasted in water transit from a central heater to the shower. 

This on-demand heating means energy is only used when the shower is active, potentially reducing wastage. 

However, the source of electricity is crucial; if the electricity is generated from fossil fuels, the environmental benefits are offset by higher carbon emissions. 

Electric showers can be a more environmentally friendly option for households with access to renewable energy sources.

Combi Boilers

Combi boilers are generally more energy-efficient than traditional boiler systems. They heat water only when needed and do not store large quantities of hot water that can lose heat over time. 

This efficiency translates into lower carbon emissions, particularly if the boiler is gas-powered, as modern gas combi boilers tend to have higher efficiency levels. 

Additionally, integrating combi boilers with renewable energy sources like solar water heating systems can reduce their environmental impact, making them an appealing choice for eco-conscious homeowners.

Both systems could be part of a sustainable home energy solution. Still, their environmental impact largely depends on the broader energy system they are part of and the specific usage patterns in the household. 

When considering the environmental aspect, homeowners should evaluate not only the energy efficiency of the device itself but also the source of their energy and opportunities to integrate with renewable energy solutions.

Choosing the Right System for Your Home

When deciding between an electric shower and a combi boiler for your home, several factors must be considered to ensure that your chosen system aligns with your household's specific needs and lifestyle.

Factors to Consider Based on Your Needs

Family Size and Water Usage

Your household size and typical water usage are critical in determining the right system. 

A combi boiler may be more appropriate for larger families or households with high water usage as it can handle multiple water outputs simultaneously without a drop in water pressure. 

In contrast, electric showers are ideal for smaller families or homes where water usage is less intense, as they provide hot water on demand but can only supply one point at a time.

House Layout

The layout of your house also plays a significant role. 

For homes with multiple bathrooms far from the boiler, an electric shower in each bathroom can ensure that hot water is readily available where needed without the delay or heat loss that can occur with long pipe runs from a central boiler.

Existing Systems

Evaluate the existing systems in your home. 

Integrating a combi boiler could be more straightforward and cost-effective if you already have a suitable central heating system. 

However, if installing a central system requires significant restructuring, electric showers might be more practical and economical.

Energy Sources and Costs 

Consider the types of energy available to you and their costs. 

Electric showers are more beneficial in areas with higher gas prices or where electricity comes from renewable sources, making them environmentally friendly and cheaper.

Recommendations Based on Common Scenarios

  • For New Homes or Major Renovations: Consider installing a combi boiler in the initial construction phase to maximise integration and efficiency across heating and hot water systems.

  • For Adding a Bathroom or Retrofitting: An electric shower can be an excellent choice for adding a shower to a home without extensive plumbing modifications, especially in spaces like basements or conversions where running large amounts of pipework would be challenging.

  • Environmental Considerations: If reducing your carbon footprint is a priority, evaluate each option's energy efficiency and consider the source of your electricity or gas. Modern combi boilers or electric showers with energy-saving features might be preferable.

By carefully considering these factors, you can choose a system that meets your immediate needs and offers long-term satisfaction and efficiency. 

Making the right choice helps ensure your home remains comfortable, cost-effective, and aligned with your environmental values.

© Copyright 2024 Best Electric Shower LTD. All rights reserved. | Company Number: 15606794 | Registered in England and Wales with registered office in Linden Fields, Tunbridge Wells, England, TN2 5QX

Email Support: support@bestelectricshower.co.uk | Customer Support: 02081752283  

Privacy Policy | Cookie Policy | Terms of UseAffiliate Policy

© Copyright 2024 Best Electric Shower LTD All rights reserved | Company Number: 15606794 | Registered in England and Wales with registered office in Linden Fields, Tunbridge Wells, England, TN2 5QX

Email Support: support@bestelectricshower.co.uk | Customer Support: 02081752283  

Privacy Policy | Cookie Policy | Terms of UseAffiliate Policy

© Copyright 2024 Best Electric Shower LTD All rights reserved | Company Number: 15606794 | Registered in England and Wales with registered office in Linden Fields, Tunbridge Wells, England, TN2 5QX

Email Support: support@bestelectricshower.co.uk | Customer Support: 02081752283  

Privacy Policy | Cookie Policy | Terms of UseAffiliate Policy


Free Guide: Ultimate Buyer's Guide to Electric Showers