The test regime covers the performance of HIUs designed for space and domestic hot water (DHW) production, which includes pressure tests, static tests, dynamic tests, keep warm tests and low DHW flow tests. Provision is made in the regime to carry out testing at both high and low primary side temperatures.

Testing is carried out in BSRIA’s dedicated environmental chamber, where clients can witness the testing and observe live test data, while also using the facility for product development purposes. 

Tom Garrigan, BSRIA Test House business manager, said: “Attaining UKAS accreditation for HIU testing further extends our product test offering and meets a growing need within the industry to comply with the BESA UK HIU Test Regime. The accreditation provides our clients with the reassurance they are getting quality test data.”

In 2016 around 44,800 HIUs were installed in the UK, with the majority fitted in buildings served by central plant systems. 54,700 HIUs were installed in 2017, representing a 22 per cent growth of the market. Since then, the market size has been revised upwards.

There are already a large number of suppliers of HIUs in the UK; in 2017, it was estimated that over 60 suppliers were active in the market. Many boiler and controls manufacturers have entered the market in the last few years and the number of new entrants is expected to keep increasing, particularly in the short-term.