Harlequin HeatStream Electric 150L Direct Mains Hot Water System

Key Information

• 150-litre capacity — ideal for flats, apartments, and electrically heated homes
• Open-vented thermal store design — not subject to Part G Building Regulations
• Mains pressure hot water — delivers strong and consistent performance
• Secondary boost immerison heater — provides up to 50 litres of hot water in approximately 20 minutes
• ErP B energy rating — supports efficient energy usage
• Low standing heat loss — only 1.12kWh per day
• Compatible with off-peak tariffs — helps reduce running costs
• Suitable for use with solar PV systems — maximises renewable energy usage
• Compact 520mm x 520mm footprint — ideal for smaller airing cupboards
• Polypropylene inner tank — non-corrosive and ideal for poor water quality areas
• Reduced legionella risk — supports improved water hygiene
• 5-year warranty — long-term peace of mind

What's Included

• Harlequin HeatStream Electric 150L Direct Mains Hot Water System - HS150E

The Harlequin HeatStream Electric 150L Direct Mains Hot Water System provides a practical and energy-efficient solution for delivering reliable hot water in electrically heated homes, flats, and apartments. Designed to store and heat up to 150 litres of water, it offers an excellent balance between capacity, performance, and installation flexibility.

Its compact footprint and innovative thermal store design make it particularly well suited to modern properties where space is limited but hot water demand remains high.

Designed for Simpler Installation

Unlike traditional unvented cylinders, the HeatStream Electric is an open-vented thermal store, meaning it is not subject to Part G Building Regulations in the UK. This removes many of the installation requirements associated with unvented systems, including expansion vessels, temperature and pressure relief valves, and G3-qualified installation.

The result is a simpler, more straightforward installation process with lower overall installation costs.

Fast Hot Water Recovery

The system includes a secondary fast heat-up boost immersion heater capable of providing up to 50 litres of hot water in as little as 20 minutes. This makes it ideal for busy households where additional hot water may be required at short notice.

Stainless steel corrugated coils with a large surface area help deliver rapid heat transfer, ensuring excellent performance throughout the day.

Energy Efficient and Solar Ready

With an ErP B energy efficiency rating and standing heat losses of just 1.12kWh per day, the HeatStream Electric is designed to minimise energy waste. It can also help maximise the benefits of off-peak electricity tariffs and solar PV installations, allowing homeowners to make better use of lower-cost or renewable energy sources.

This makes it an efficient addition to modern heating systems.

Durable, Reliable, and Low Maintenance

The inner tank is manufactured from non-corrosive polypropylene, making it particularly suitable for areas with poor water quality. With very few moving parts and only a simple six-monthly top-up requirement, ongoing maintenance is kept to a minimum.

The design also helps reduce the risk of Legionella growth, providing additional reassurance for homeowners.

Ready to Upgrade Your Heating System?

If you're looking for an efficient alternative to traditional cylinders and storage tanks, the Harlequin HeatStream Electric 150L offers reliable hot water performance with simplified installation and low running costs.