What are heat interface units?

Heat interface units also known as HIU systems act as a bridge between the central boilers and the heating and hot water systems within a property. These are typically installed within large apartment blocks with multiple homes rather than having to fit each apartment with a boiler. With HIU you can have one central boiler system which provides heating and hot water to the entire block of flats. This not only saves costs but also maximise the use of space available within each property.

The hot water produced by the centralised boiler system is transferred via heat exchangers, to provide each apartment with on-demand heating and hot water. Heat interface units can be designed to work alongside other renewable technologies such as solar PV or air source heat pumps.

Types of heat interface units?

Direct heating

Direct heat interface units provide a direct connection between the primary system and the secondary system.

Indirect heating

Indirect heat interface units have a plate heat exchanger separating the primary and secondary systems to transfer energy from the fluid in the primary system to the fluid in the secondary system.

Benefits of heat interface units?

Cheaper and easier to install

HIU systems are cheaper and easier to install within a large block of flats you don’t need to purchase and fit an individual boiler to each apartment. You have one main boiler and only need to install the controls which are far cheaper, easier to install and also saves space within the properties. There is also no need to spend money on installing a gas network to the block as the heat interface units don’t require a gas connection or flue pipe so ventilation routes are not required.

Minimal maintenance & disruption

The heat interface units themselves require very minimal maintenance and the only main regular maintenance required will be to the communal boiler. This means occupants will no longer have to wait in their home for their regular servicing as the gas-qualified engineer will only need access to communal areas which means minimal disruption to the block.

Reduce your carbon footprint and help save the environment

Heat interface units usually work in conjunction with other renewable technologies in order to reduce the carbon footprint of the block. This technology is a way that each property can help towards protecting the environment and tackling climate change by utilising natural sustainable resources.

Heat interface unit maintenance services

Most manufacturer’s warranties are only upheld if your renewable technology is regularly maintained, which is why it is important to ensure your heat interface units are serviced frequently by qualified engineers. This will not only guarantee your system’s performance throughout the year and prolong the lifetime of the technology but it will also save you money on repairs as most parts are covered by warranty for approximately 10 to 15 years.

We provide both planned maintenance as well as operations and maintenance (O&M) contracts for heat interface units. As part of these packages, one of our qualified and experienced engineers will attend your property to carry out a thorough annual service of your heat interface unit. We will also attend your property for any reactive / emergency repairs.

We not only provide reactive call outs for our clients signed up to our maintenance contracts but will also attend emergency repairs for none clients as well.

What’s included in the annual service for your heat interface unit?

• Check and clean the strainers.

• Inspect the functionality of the pumps.

• Check the system operating parameters.

• Check and clean the port valves.

• Check for leaks and pressure drops in both the primary and secondary sides of the heat exchangers.

• Annual service certificate issued.

• Provide service maintenance document.