HIU Service

Heat Interface Units (HIUs) in Luxury Apartments

In most modern, high-rise luxury developments, Heat Interface Units (HIUs) are the primary system for delivering both heating and instantaneous hot water to individual apartments. They connect the building’s central energy plant to each home, providing on-demand thermal comfort while maintaining the clean aesthetics and space-saving design that premium properties demand.

It is essential to carry out annual servicing of these units to ensure efficient running costs and also to reduce the possibility of the unit or its components failing.

🔧 What Our Specialist HIU Service Covers

Our Planned Preventative Maintenance (PPM) for HIUs is engineered to maximise performance, extend equipment life, and minimise energy waste. Our detailed service includes:

• Cleaning of landlord -side strainers to ensure unimpeded flow and system efficiency

• Cleaning of apartment-side strainers to ensure unimpeded flow and system efficiency

• Leak, corrosion, and component checks across the entire unit

• Safety relief valve testing to confirm compliance and functional integrity

• Expansion vessel inspection and recharging, maintaining safe pressure levels

• Examination of room heating controls and thermostats to ensure accurate regulation

• Water quality testing on the secondary heating circuit—checking inhibitor strength, corrosion risk, and pH levels

• Pump diagnostics and re-setting, where required

• Flow rate and temperature checks on both heating and domestic hot water circuits

• Evaluation of integrated energy meters for accurate billing and performance tracking

Each service concludes with a digital service report, recording maintenance history and performance observations—essential for long-term system oversight.

🌟 Benefits to the High-End Occupier

Annual HIU servicing delivers numerous advantages to residents and owners of luxury apartments:

• Efficiency Optimised – Proper calibration reduces energy usage and running costs

• Peak Comfort – Ensures immediate and consistent hot water and space heating

• Extended System Life – Prevents premature wear and delays costly replacements

• Quiet, Trouble-Free Operation – Reduces the chance of in-unit faults or disruptions

• Approved, Specialist Care – Our engineers work only with original parts—never grey market substitutes

• Trusted Documentation – Service history supports building compliance, warranties, and resale assurance

🛠️ Specialist Accreditation Sets Us Apart

HIU is still a niche equipment and most regular plumbers or gas engineers lack accredited training with how a HIU unit operates. Employing a specialist will provide you with an engineer who have in-depth knowledge of different types and brands of HIUs.

Unlike general plumbers or gas engineers, HIU servicing requires dedicated training and hands-on experience across multiple unit types and control systems. At Maintainmyhome, our engineers are:

• Tier 1 Approved by SAV Systems – the UK’s market leader in HIUs

• Regular attendees of the SAV Advanced Engineer Training Course

• Accredited by other major manufacturers, including YGHP,( https://www.yghp.co.uk/indirect-heat-interface-unit/)  Caleffi (https://www.caleffi.com/en-int/electronic-wall-hanging-hiu-with-hydraulic-separation--satk30-caleffi-satk30103he, KAMO (https://www.uponor.com/en-en/products/prefabricated-systems/pre-fab-heat-interface-unit) INTATEC and more

This investment in training and technical excellence ensures your unit receives the expert attention it deserves—with genuine replacement parts, precise diagnostics, and factory-approved methods.

💡 Who is Responsible for HIU Servicing?

In some developments, the building management company or energy provider may arrange partial or full HIU servicing. Before booking your own service, check the terms of your lease or consult your managing agent. Scenarios typically fall into one of three categories:

1. Most Common – No maintenance is provided: the occupier/leaseholder is fully responsible

2. Partial Coverage – Only the landlord’s side (primary loop) is maintained: the occupier must maintain the in-flat components

3. Rare – Full HIU maintenance is centrally arranged, covering both landlord and apartment sides

   
   

⚠️ Your lease may not clearly define this responsibility—confirm in writing to avoid unnecessary cost or missed obligations.