The CENTRALflow heat interface unit provides a unique and energy efficient heating and hot water storage solution for apartment blocks or properties where the heat comes from a centralised source such as a biomass or CHP Plant.

CENTRALflow delivers mains pressure hot water through a thermal store linked to a Heat Interface Unit (HIU) which can also offer a Heat Metering facility.

The CENTRALflow solution also enables other forms of renewable energy, such as solar thermal technology to be included to reduce the carbon footprint and minimise operating costs.

CENTRALflow Heat Interface Unit Core Benefits

Main Pressure Hot Water Storage System
• No Gas Pipe-work or Carbon Monoxide Issues
• No G3 Certification Required For Installation
• Simplified Installation & Reduced Maintenance
• Immersion Heater Back-up for Summer Use
• Reduced Central Boiler & Pipe-work Size
• Heat Metering & Pay As You Go Options

Indirect heat interface unit type hot water storage system



• Provides full separation between the primary circuit and the individual apartments 
• Suitable for private housing with limited access
• Allows occupant to control their own heating and water supplies





DIRECT HEAT INTERFACE UNIT TYPE 2Direct heat interface unit type 2. Hot water storage system from McDonald Engineers, UK.

• No separation between primary circuit and individual apartments
• Suitable for social housing where access is easily obtained
• Allows occupant to control their own heating and water supplies





Due to the nature of the product, each heat interface unit is designed and manufactured to order allowing complete flexibility on sizing, fuel sources and connection placement.

For further information on the CENTRALflow heat interface unit, our Technical Sales Team are on hand to discuss the optimum solution for your requirements and can carry out full site surveys.

Download our Centralflow Technical Presentation for information on our heat interface and hot water storage solutions


For more information or to discuss your requirements contact us now on 01592 611123.


 CENTRALflow: Energy efficient heat interface unit with hot water storage from McDonald Water Storage.