How does a Heat Interface Unit (HIU) work?

A Heat Interface Unit or HIU in a residential dwelling or commercial premises acts as an interface between a heat network and an end user (homeowner, or commercial end user). Heat enters the premises through insulated pipework connected to the heat network; this pipework passes the heat into the HIU.


The HIU generally contains plate heat exchangers which transfer the heat from the network to the individual building, these plates also act as a pressure break between the network and the end user. The HIU transfer the heat into an underfloor, or radiator heating system and in some products can be used for DHW production.

Take a look at Baxi's AquaHeat HIU 

For homes fed with heat from a heat network, the Baxi AquaHeat is the answer to your apartment’s heating and hot water requirements. Perfectly suited to supply heat to communal and commercial premises in your development.

Related FAQs

Heat Interface Unit (HIU) efficiency 

Using a twin plate HIU (indirect Heating & Domestic Hot Water) as an example, there are a few ways in which product efficiency can be measured. Read more..

Heat Interface Unit (HIU) pros and cons

Find out the pros and cons of Heat Interface Units (HIUs) here at Baxi FAQs...

How to reset pressure on my Heat Interface Unit (HIU)? 

Watch this video to find out how to reset pressure on my Heat Interface Unit (HIU)...

What is the price of a HIU (Heat Interface Unit)?

Average cost for a Heat Interface Unit (HIU) can be from around £800 to £1500, depending on the HIU type, performance of the unit and equipment provided.

What support is available in the design of my system?

Our Application Engineers can assist in advising clearances, dimensions, and possible locations for consideration. Find out more...

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