Heat Interface Unit Specialists

    HIU Repair & Servicing London

    HIU Service repairs, services, replaces and commissions heat interface units in London flats, estates and communal or district heating schemes, working for managing agents, housing providers, contractors and building owners.

    Call 0208 935 5572

    Commercial rate: £75+VAT per half hour, minimum 1-hour charge

    Heat interface unit engineers for London buildings

    A heat interface unit (HIU) is the hydraulic link between a building’s communal or district heating network and each individual flat. It uses plate heat exchangers to pass heat from the primary circuit to the flat’s secondary heating and domestic hot water, while a pressure-independent control valve (PICV) and controls keep flow and return temperatures where the network needs them.

    When an HIU drifts out of setup, the symptoms show up fast: no hot water, lukewarm taps, radiators that never get hot, high return temperatures across the scheme and rising heat bills. We diagnose the cause at the unit and on the network side rather than simply swapping parts.

    • No hot water and no heating fault-finding in occupied flats
    • Planned servicing and annual maintenance across whole blocks
    • Like-for-like and upgrade HIU replacement
    • Commissioning, balancing and return-temperature optimisation
    • Support for communal and district heating plant teams

    Who we work for

    Our work is commercial: managing agents, residents’ management companies, housing associations, build-to-rent operators, heat network operators and main contractors who need a dependable engineer to keep a scheme running. We report clearly on every visit so you can show leaseholders and residents exactly what was found and done.

    Common Questions

    What is a heat interface unit?

    An HIU is a wall-mounted unit in each flat that transfers heat from a communal or district heating network to the flat’s heating and hot water through plate heat exchangers, controlled by a PICV and the unit’s controls.

    Do you work on residential flats as well as plant rooms?

    Yes. We attend individual flats for HIU faults and also work with the building’s plant room team on network-side issues that affect several units.

    How much do you charge?

    Labour is charged at £75+VAT per half hour, minimum 1-hour charge. Parts and replacement units are quoted before any work goes ahead.

    Which areas do you cover?

    We cover London and the South East, with most of our HIU work in Greater London blocks and estates.

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    • UK-based coordinators — no overseas call centres
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