Heat Interface Unit Service, Repairs, and Maintenance in London

Professional HIU engineers for servicing, repairs and maintenance across London

Expert HIU Servicing, HIU Repair & HIU Replacement in London

Specialist Heat Interface Unit engineers providing professional HIU servicing, fault diagnosis, repairs and replacement support across London and Greater London. We work with homeowners, landlords, managing agents and residential developments to restore heating and hot water quickly and professionally.

Need Urgent HIU Repair?

Professional help for HIU faults, breakdowns and heating issues across London.

CALL AN ENGINEER

Emergency support available 24/7

SERVICE AREA

Greater London

SPECIALISTS IN

HIU Systems

TRUSTED BY

Residents & Agents

SUPPORT FOR

Breakdowns & Maintenance

We Service All Major HIU Brands

WHY CHOOSE HIUEXPERTS

Effective HIU servicing and repair rely on accurate diagnosis, the right parts knowledge, and engineers who work on communal heating systems every day.

Experienced professionals

Our experienced HIU engineers bring hands-on expertise in diagnosing and resolving heating and hot water issues across a wide range of HIU systems.

Fast emergency support

We respond quickly to urgent HIU faults, helping minimise disruption and restore system performance as soon as possible across London.

Transparent pricing

We offer clear and competitive pricing, explaining repair options before any work is approved so clients know exactly what to expect.

Customer satisfaction

Our focus on professional service, clear communication and dependable support has helped us build strong relationships with residents, landlords and managing agents across London.

OUR SPECIALIST SERVICES

Professional HIU support for servicing, repairs, replacement, and communal heating support

Specialist support for HIU servicing, HIU repair, HIU replacement, Parts replacement, Commissioning, and Cylinders & Thermal Stores across London.

HIU Servicing

Professional HIU servicing, including inspections, performance checks and routine maintenance support.

HIU Repair

Fast HIU repair in London for no hot water, no heating, leaks, pressure issues and breakdown faults.

Heat Interface Unit system installation and servicing work carried out in London building

HIU Replacement

HIU replacement in London for older, unreliable or uneconomical-to-repair units.

Mixing Blending valve connection on HIU heating system during repair in London

HIU Parts Replacement

Replacement of faulty HIU parts using original, brand-new components for reliable & efficient performance.

HIU Commissioning

Professional commissioning and setup support for newly installed HIU systems and related controls.

Cylinder & Thermal Store

Specialist fault diagnosis, repair and replacement support for cylinders and thermal stores in London.

Frequently Asked Questions

A Heat Interface Unit (HIU) is a compact heat exchange system installed in properties connected to a communal or district heating network. Instead of having an individual boiler, the HIU transfers heat from a central plant room to provide domestic hot water and heating within the property. It contains components such as a plate heat exchanger, control valves, sensors and pressure controls to regulate temperature, flow and system safety. Proper servicing ensures the HIU operates efficiently, safely and reliably.

Noise from an HIU can be caused by several issues, including trapped air in the system, incorrect flow rates, worn or sticking control valves, pump vibration, pressure imbalance, or scaling within the plate heat exchanger. In some cases, noise may also originate from the communal heat network rather than the HIU itself. A proper diagnostic check is required to identify whether the issue is hydraulic, mechanical or related to system settings, and to prevent further wear or performance issues.

The most common HIU issues include no hot water, heating not working, pressure loss, fault codes on the display, temperature fluctuations, and leaks from valves or internal components. Our engineers carry out a full diagnostic assessment to determine whether the fault is within the HIU itself or related to the wider communal heat network.

Heating and domestic hot water are controlled separately inside the HIU. A fault may affect one circuit only. Common causes include actuator failure, blocked filters, incorrect flow rates, sensor issues or thermostat settings. A full diagnostic check confirms the exact cause.

Frequent pressure drops may indicate an internal leak, expansion vessel issue or pressure relief discharge. Avoid repeatedly topping up the system without diagnosis, as this may worsen the problem. Contact an engineer for proper inspection.

HIU repair costs depend on the type of fault, required parts and diagnostic time. Minor issues such as blocked strainers or valve adjustments may be resolved quickly, while component replacements (e.g. actuators, sensors or plate heat exchangers) vary in cost. We provide clear pricing before any work is carried out and confirm parts costs in writing.

Yes. Annual HIU servicing is recommended to maintain performance, improve energy efficiency and reduce the risk of unexpected breakdowns. Regular servicing also helps protect manufacturer warranty conditions where applicable.

A typical HIU service includes:
Inspection for leaks and corrosion
Cleaning strainers and filters
Pressure and temperature checks
Expansion vessel pressure testing
Valve and actuator testing
Flow rate verification
Performance testing for heating and hot water
Written service report with recommendations

Yes. We provide fast-response HIU breakdown services across London. Priority is given to properties with complete loss of heating or hot water. Sharing the HIU brand and any fault code helps speed up diagnosis.

We regularly service and repair HIUs from leading manufacturers including Danfoss, Caleffi, KaMo, Evinox, Switch2, KVM, Vital Energi, Rhico and others commonly installed in London apartment blocks.

Replacement may be recommended if:
The unit is over 10–15 years old
Major components repeatedly fail
Spare parts are no longer available
Efficiency is significantly reduced
We provide honest advice based on condition and cost comparison.

Yes. We provide planned HIU servicing programmes for residential blocks and managing agents, including scheduled annual servicing, bulk bookings and detailed reporting for compliance records.

We cover London and the surrounding areas. Contact us with your postcode to confirm availability.

Most diagnostic visits take 45–90 minutes. Minor repairs can often be completed during the first visit, depending on parts availability and access conditions.

Arrange an Appointment or Contact Our Team

07350705111