HIUs in Brentford's new developments: what residents need to know

If you've moved into one of Brentford's newer developments, you may have noticed something missing: a boiler. Instead, there's a white unit in a cupboard called a Heat Interface Unit, or HIU. It takes heat from your building's communal heat network and transfers it to your own radiators and hot water — instantly, and without burning gas in your flat.

HIUs are efficient and safe, but they're not maintenance-free. Inside are plate heat exchangers, control valves, actuators and filters — components that scale up, stick and wear just like boiler parts. The difference is that when an HIU fails, many general plumbers simply won't touch it.

The most common problems we see across Brentford's heat network homes: lukewarm or intermittent hot water (usually a scaled plate heat exchanger or failing control valve), heating that won't respond (often an actuator), and pressure loss on the heating circuit.

Annual servicing matters for HIUs too. A clean filter and correctly calibrated controls don't just prevent breakdowns — on metered heat networks, an efficient HIU directly reduces your monthly heat bill.

We're based in Brentford TW8, minutes from the riverside developments, and we repair and service all major HIU brands. If your flat's hot water isn't behaving, our HIU page covers everything — or just call and describe the problem.