Hot water is a daily necessity—whether it’s for your morning shower, washing dishes, or running a warm bath after a long day. In the UK, where space is often limited and energy efficiency is a growing concern, tankless electric water heaters are becoming an increasingly popular choice. These compact systems heat water instantly as it flows through the unit, meaning you’ll never run out of hot water and you won’t waste energy keeping a large tank warm all day.
In this guide, we’ll explore the best tankless electric water heaters available in the UK for 2025, what makes them ideal for UK homes, and how to choose the right one. We’ll also share installation and maintenance tips and discuss an often-overlooked part of your plumbing system that could save you costly repairs in the future.
Why Choose a Tankless Electric Water Heater in the UK?
Tankless electric water heaters are particularly appealing in the UK for several reasons:
- Space-saving design: Ideal for flats, small houses, and properties with limited storage.
- On-demand heating: Water is heated instantly, so there’s no waiting for a tank to refill.
- Energy efficiency: No standby heat loss—only heats the water you use.
- Simple installation: No flue or gas supply needed.
- Eco-friendly option: Works well with renewable electricity sources.
Best Overall: Stiebel Eltron DHC-E 12
The Stiebel Eltron DHC-E 12 is a high-quality, German-engineered tankless electric water heater designed for consistent performance and long life. It’s ideal for point-of-use applications such as a single shower or kitchen sink, and it’s known for excellent build quality and stable water temperature.
- Output: Suitable for single points of use or smaller demand applications.
- Temperature control: Digital settings for precise adjustment.
- Design: Compact and discreet for easy installation in cupboards or under sinks.
- Durability: Built to handle hard water areas with minimal maintenance.
Other Top Tankless Electric Water Heaters in the UK
Mira Advance ATL
Perfect for electric showers, this unit offers advanced thermostatic temperature stability and is designed with accessibility in mind. It’s reliable, stylish, and easy to use.
Triton T80z Fast-Fit
A UK favourite, the Triton T80z is simple to install, affordable, and available in multiple power ratings. Ideal for replacing older electric showers.
Redring Powerstream
Compact and efficient, the Redring Powerstream provides instant hot water for hand basins and kitchens. Great for small commercial or domestic applications.
Hyco Speedflow
Designed for under-sink installation, this model is a solid choice for small kitchens, offices, and washrooms where quick hot water is needed.
How to Choose the Right Tankless Electric Water Heater in the UK
Before you purchase, consider the following factors:
- Intended use: Whole-home electric tankless units are rare in the UK due to electrical capacity limits, so most installations are point-of-use.
- Power rating (kW): Higher ratings deliver hotter water at higher flow rates but require more electrical capacity.
- Water pressure: Ensure your home’s pressure meets the unit’s requirements for optimal performance.
- Location: Units can be fitted in bathrooms, kitchens, or utility areas—choose one with a suitable ingress protection (IP) rating for the location.
Pro Tip: In colder months, incoming water temperatures in the UK can drop significantly. This means a high-kW unit will be more effective in maintaining comfortable hot water output.
Installation Considerations
In the UK, all electric water heater installations must comply with IET wiring regulations and, if installed in bathrooms, Part P of the Building Regulations. Key points include:
- Using a qualified electrician for installation.
- Ensuring the electrical supply is sufficient for the chosen unit.
- Installing close to the point of use to minimise heat loss.
Maintenance Tips
Tankless electric water heaters are generally low-maintenance but will last longer with proper care:
- Descale annually in hard water areas to prevent limescale buildup.
- Check for leaks and loose fittings regularly.
- Clean filters or inlet screens as needed.
The Overlooked Side of Your Plumbing System
Even the best water heater can’t save you from problems if your wastewater system fails. Many UK rural homes still rely on septic tanks, and without proper maintenance, these systems can develop blockages, cause bad odours, and even lead to expensive overhauls.
Hot water use from a tankless system can place additional strain on a poorly maintained septic system. Prevention is much cheaper than repair.
SEPTIFIX – Protect Your Septic System
SEPTIFIX is the #1 septic tank treatment in both the UK and North America. These flushable tablets release oxygen and beneficial bacteria to break down waste, sludge, and grease while eliminating foul odours.
Benefits include:
- Removes unpleasant smells in just a few days.
- Prevents costly backups and pump-outs.
- Safe for all septic systems and eco-friendly.
- Easy to use—just flush one tablet each month.
Pairing your new tankless water heater with regular SEPTIFIX treatment ensures your entire plumbing system stays in peak condition.
Final Thoughts
For UK homes in 2025, the Stiebel Eltron DHC-E 12 is the best overall tankless electric water heater, offering precision, quality, and reliability. Other excellent options include the Mira Advance ATL, Triton T80z Fast-Fit, Redring Powerstream, and Hyco Speedflow.
And remember—endless hot water is only part of a comfortable home. A healthy septic system, maintained with SEPTIFIX, ensures your plumbing runs smoothly for years to come.
Order SEPTIFIX Today – Keep Your Septic Tank Healthy and Odour-Free
Hot water you can rely on, plus a trouble-free septic system—that’s peace of mind for UK homeowners.