Heat Interface Unit (HIU)

Welcome to Heat-Plex Limited, London’s top choice for reliable Heat Interface Unit (HIU) repairs and maintenance. We are dedicated to ensuring your heating systems operate at peak efficiency.

Repair & service

Efficient HIU Services for Your Business

At Heat-Plex, we understand how disruptive HIU issues can be, whether it’s a faulty heat exchanger, inconsistent heating, or a malfunctioning control unit. We pride ourselves on providing prompt, reliable, and friendly HIU services. No job is too small, and most HIU repairs can be completed within the first hour of our visit. We ensure you’re kept in the loop throughout the process, providing clear communication at each step.

Faulty Heat Exchangers

We quickly diagnose and repair or replace faulty heat exchangers to restore your system’s efficiency.

Inconsistent Heating

Our team inspects and adjusts your HIU to ensure consistent heat distribution, enhancing comfort and performance.

Malfunctioning Control Units

We troubleshoot and repair control units, ensuring smooth operation and optimal control over your heating system.

heating and hot water

Reliable HIU Services for Your Comfort

Don’t let HIU issues disrupt your business. With Heat-Plex, rest assured that your heating system is in safe hands. Regular maintenance can prevent unexpected breakdowns and extend your HIU’s lifespan. Get in touch with us now to book your HIU service.

Trusted Expertise with Leading HIU Brands

Our certified engineers specialise in servicing top HIU models, including Danfoss, Evinox, Caleffi, and Altechnic. We handle routine maintenance and emergency repairs with skill and precision.

Why Choose Heat-Plex?

Expertise and Experience

Our certified engineers specialise in HIU models like Danfoss, Evinox, Caleffi, and Altechnic. We handle routine maintenance and emergency repairs with skill and precision.

Comprehensive Maintenance Plans

We offer tailored maintenance plans to keep your HIU running smoothly, preventing breakdowns and extending its life. Flexible scheduling ensures minimal disruption to your routine.

Prompt and Reliable Repairs

We understand HIU issues are urgent. Our team is committed to fast, reliable repairs, restoring your heating and hot water supply efficiently to minimise inconvenience.

Customer-Centric Approach

From your first contact, we aim to provide a seamless experience. Our friendly staff are ready to assist, keeping you informed throughout the process for complete peace of mind.

Quality and Safety Assurance

We use top-quality parts and equipment, adhering to strict safety standards. Our goal is to deliver lasting, reliable solutions for your HIU system.

Environmentally Responsible

Our services reduce energy consumption and lower your carbon footprint, contributing to a greener London while saving you money.

What Our Customers Say

Beverley LindsayBeverley Lindsay
17:29 26 Jun 24
Brilliant service as always.
Vicky WootenVicky Wooten
06:39 24 Jun 24
Joe and team have always does a great job from initial install to the servicing and providing gas safety certificates each year. I would highly recommend him and his friendly team for any heating requirements.
fiona bluckfiona bluck
08:01 12 Jun 24
Ealy (spelling?) did a fantastic job fixing my boiler after at least six other plumbers had failed. Highly recommend. Fiona
Ant HAnt H
14:28 16 May 24
What a wonderful service. I was so impressed with the two engineers that attended. They arrived on time, were friendly, professional and did a great job. On top of all that very good value. I will definitely be using them again.
12:40 13 May 24
Excellent service and install of a new boiler - very easy process, can recommend
21:49 16 Apr 24
After experiencing a terrible experience with a dubious online company who deceived me, overcharged me, did not fulfill their job and disappeared, I was looking for a good and honest plumber to fix the problem of my hot water cylinder. One of my friends recommended Joe and his company to me and after contacting Joe and talking to him I immediately felt I was in good hands. Joe is very professional, kind, reliable and respectful. He is honest and a brilliant plumber. He identify the problems and he provided immediate fix at the first visit. The amount paid for Joe’s work was very reasonable (I was expecting more!) and certainly his work ethos, transparency and knowledge are worth more! I would implicitly recommend Joe to anyone looking for a plumber. I will certainly be using his company in the future for any plumbing issues in my property.
John grayJohn gray
10:35 16 Apr 24
Really great service from Joe and the team. Would recommend. Was quick and easy to use Heat Plex, Joe was able to sort out a full boiler replacement for me in 2 days from the first phone call and was able to start work the day after our first phone call.
Caitlin SmithCaitlin Smith
17:24 02 Feb 23
Heatplex were great. They were able to help us out at short notice and get our old and faulty boiler working again. They were knowledge, easy to work with and efficient. Would recommend.
Fen PengelleyFen Pengelley
10:09 12 Dec 22
Joe was amazing at sorting our broken heating system, he is incredibly knowledgeable and very friendly. We have found him to be extremely reliable and assisting us with any follow up questions we needed help on. I always recommend him as the go to specialist in the SW London area.
Debbie HendersonDebbie Henderson
10:00 11 Nov 22
We've used Joe for quite a few years now. He does our annual boiler and gas fire service plus we also used him when we had a leak under our bath and more recently to replace all of the valves on our radiators. We are more than happy with the services that Joe provides. He's responsive, honest, friendly and courteous. I find that it can be difficult to get good tradespeople at the moment, especially ones that are responsive and I'm so glad that we found Joe a few years ago and can rely on him!
Alexandra WhiteAlexandra White
22:34 10 Nov 22
Joe did a great job installing my new boiler, quickly, reliably and efficiently. He provided an excellent service, even sending me a how to video (twice after I lost the first one). He puts a lot of care into the job and I would highly recommend him!
James LittmannJames Littmann
13:24 30 Sep 21
I've been using Joe for years - since he was a one man band. He's serviced our own boiler, as well as carrying out service and safety maintenance on our rental property. He's always been honest, good value and very reliable. He's also a genuinely lovey guy. I've recommended him to lots of people over the years. It's been a pleasure watching his business grow over the year and he deserves every success.

Heat Interface Unit FAQs

A Heat Interface Unit (HIU) is a device used in buildings with communal or district heating systems to transfer heat from a central boiler to individual apartments or units, providing heating and hot water.


It’s recommended to have your HIU serviced annually to ensure it operates efficiently and to prevent unexpected breakdowns.


Common issues include faulty heat exchangers, inconsistent heating, and malfunctioning control units. Regular maintenance can help prevent these problems.


Heat-Plex offers expert diagnosis, repair, and maintenance services for HIUs, ensuring your system runs smoothly and efficiently.


Yes, Heat-Plex provides prompt and reliable emergency repair services to address urgent HIU issues and minimize downtime.


We specialise in servicing a variety of HIU models, including Danfoss, Evinox, Caleffi, and Altechnic.


You can easily book an HIU service by contacting our friendly team through our website or by phone. We’re here to help!



Need help with your heating?

Make An Enquiry

To make a booking with us, please fill out our short form below and describe the problem you are having.

Service Plan Enquiry

Thanks for showing interest in one of our service plans please fill in the information below and one of our specialists will be in touch to run you through your options.

Make An Enquiry

To make a booking with us, please fill out our short form below and describe the problem you are having.