HIU (Heat Interface Unit)

Heat interface units need specialist engineers. Not general plumbers who have to google the manual on site. We service, repair and install HIUs across London every week.

London's trusted heat interface unit specialists

An HIU connects an individual flat to the building’s communal heating system. When it fails, that flat loses heating and hot water even though the plant room is running perfectly. The problem is almost always inside the unit.

These are not straightforward appliances. Plate heat exchangers, differential pressure regulators, motorised valves, electronic controls. Send a general plumber who has never worked on one before and they will spend three hours chasing the wrong fault. We work on HIUs every week. We know what goes wrong with them and we carry the common spares on the van.

For managing agents and housing associations, we offer planned maintenance contracts. Every unit in the building serviced on schedule, one point of contact, consistent quality. When a resident calls with a fault, we know the building, we know the system, and we usually know what the problem is before we walk through the door.

WHAT WE COVER

Our HIU (heat interface unit) services

HIU servicing

Annual service to keep it running efficiently and catch problems early

Repairs

Fault diagnosis and component replacement. Most parts carried on the van

Installation

New units fitted and commissioned

Descaling

Heat exchangers cleaned to restore proper heat transfer

Valve and actuator work

Control valves and motorised actuators replaced when they fail

Maintenance contracts

Scheduled servicing for whole buildings

HOW IT WORKS

Simple from start to finish

Get in touch

Call or fill in our quote form with details of what you need

Site survey

We assess the job and provide a fixed price quote

We do the work

Our qualified engineers complete the job to the highest standard

Guaranteed

12 month guarantee on all parts and labour

PRICING

HIU rates

HIU service

£120

Per unit

All prices are subject to VAT. Materials charged separately. Minimum 1 hour on all jobs. Parking and congestion charges may apply.

Recommended for issues to do with block management

“I would highly recommend Sandhurst plumbing, i have used them several times for issues to do with block management. They were punctual, happy to help and Nicola has always been on hand to get this booked and kept us updated through out any jobs.”

FAQS

Common questions

What actually is an HIU?

It is the equivalent of a boiler, but for flats on communal heating. The building has a central plant room that produces hot water. The HIU in each flat takes that heat and converts it into usable heating and domestic hot water for that specific flat.

How often should it be serviced?

Once a year. The heat exchangers scale up, the filters clog, the valves wear. Regular servicing prevents the kind of breakdown that leaves a resident with no hot water on a cold Monday morning.

No hot water but the heating works. Is it the HIU?

Quite possibly. HIUs have separate circuits for heating and hot water. A fault on the domestic hot water side leaves the heating completely unaffected. Give us a call and we can talk through it.

Do you work with managing agents?

A lot of our HIU work comes through managing agents and housing associations. We offer maintenance contracts, prioritised response times and proper documentation for every job.

Which brands do you work on?

All of them. We carry common spares for the most popular models. If a part needs ordering, we get it in and come back. Usually next day.

YOU MAY ALSO NEED