HIU Services London: Expert HIU Repair & Service

Cost-Effective HIU Heating and Hot Water Solutions

Dedicated Team of HIU Engineers and Customer Service Professionals


Fair, Transparent Pricing
Fixed/Hourly Repair Rates
Fixed Price Quotes
Discounted Group Rates
Spring/Summer Discounts
No Charge for Parking, CC or ULEZ
Card Payment Availability


Established in 2014
5 Star Rated Services in London
Certified HIU Experts
Danfoss and Caleffi HIU Specialists
Most Common Parts in Stock
Quick Turnaround for Non-Stock Parts


Fully Insured Services
12-Month Parts Replacement Warranty
One-Hour Response to Online Inquiries
Expert HIU Engineers in London
Endorsed by Which? Trusted Traders

Dipesh Jaichand
Easy to book, good comms, fair price and professional service. Recommended.
Daria K
Justin was great, quick to respond and changed thermostat so everything is working now, thank you
Isaac Perez
Excellent service and very professional engineers
Abi Turner
Excellent service. Reliable and value for money. Would definitely recommend.
jane tucker
Having had an estimate from another company who demanded total payment up front by bank transfer, I decide to look at other options for HIU repair. I contacted about 5 companies. Add Detail got back to me very quickly with a much better price and only wanted the cost of parts up front which I could easily pay by credit card. Jason the engineer arrived at the agreed time (he was early in fact) and did an excellent job, making sure that the system was working properly. He was very polite and made no mess. I have recommended this company to others on my development as there are always people having problems with the HIU's.
Erwin De Leon
The service timing was very efficient, engineer that attended my property was accommodating to all my questions. Service value is definitely worth it.
Michel de Baar
The service guy came out within 24 hrs of me calling them, knew to find the solution to the problem and fixed it. He was respectful and friendly, explaining along the way what he observed and gave a few tips on top of it. Thanks! Great service
David Polacek
Great service! Very punctual and professional!
Neli Valkova
Excellent company, very prompt and efficient service. Sorted out problem straight away and price was reasonable. Would highly recommend and will keep using their services. Really impressed.
Sofia Costa
Fantastic service provided by Add Detail! After two terrible experiences with other companies, I discovered Add Detail through a Google search. I messaged them on WhatsApp and received a prompt reply. A few days later, Justin came over and delivered impeccable service. Despite being initially informed that I needed a full HIU replacement, Justin skillfully replaced the malfunctioning pump, leaving everything fully operational! He was incredibly nice and helpful. I plan to rely on Add Detail for all my future HIU servicing needs. I highly recommend them.


HIU Services in London

Established in 2014 in London, ‘Add Detail Ltd’ is a recognised name in HIU services within the London community. Our team of skilled HIU service engineers are ready to assist with all your HIU system, repair, and maintenance needs, ensuring your home remains warm and comfortable.

Specializing in heat interface units, our experts have in-depth knowledge of various types and brands, enabling them to accurately diagnose and resolve specific issues. This expertise enhances your HIU’s efficiency, reduces energy costs, and extends its lifespan, helping to avoid costly replacements.

We also provide detailed digital reports and maintain a comprehensive service history, essential for maintaining optimal performance. Choosing ‘Add Detail Ltd’ means having reliable support for any district heating or hot water problems, giving you peace of mind.

Count on us to safeguard the safety, efficiency and longevity of your HIU – a smart choice for those in London seeking expert HIU care.

Fast Responses To Your HIU Enquiries Are Guaranteed!

Connect with us for professional HIU services and repair solutions in London. Reach out via our contact form or call 02088224451. Our services are fully insured, ensuring quality workmanship and peace of mind with every project. Learn more about HIUClick here.

12 Tips To Keep HIU In Tip-Top Condition

  1. HIU annual service (read more)
  2. HIU specialist company to service and repair that uses only original parts  (read more)
  3. HIU fitted with an Inline water scale reducer (read more)
  4. HIU secondary heating water quality check and inhibitor top-up (read more)
  5. HIU connected to a smart thermostat (read more)
  6. HIU secondary heating system with magnetic filter (read more)
  7. HIU heating and hot water controls explained by a HIU specialist (read more)
  8. HIU performance is affected by dripping taps and poor plumbing in the apartment (read more)
  9. HIU connected to radiators and importance of correctly working radiator valves, radiator bleeding and heating system balancing (read more)
  10. HIU connected to underfloor heating and importance of correctly working manifold, actuators, flow meters, control center wiring and room thermostats (read more)
  11. HIU repair and service record keeping and staying with the same HIU service company over the years offers several important benefits (read more)
  12. HIU problems for heating and hot water should be looked as soon as possible (read more)


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