Heat Interface Units

Why choose Smart Call?
HIU service repair in London

We are your one stop shop for all your heat interface unit repairs and requirements.

Watch our video below to learn more about our business and HIU servicing:

Turn to our Team of Fully Trained HIU Engineers

With over 25 years’ experience within the industry and based locally in London. We work alongside manufactures, you need to look no further than us for your HIU install, repairs, service, maintenance and replacement Heat Interface Units. We are specialists within the field of Heat interface units and communal systems. We have it all covered.

If a problem strikes, you can count on our team of HIU experts to get your heating and hot water back up and running as quickly as possible. Our manufacture trained HIU Engineers carry spare parts in their vans so they can assist you with a speedy repair.

Heat Interface Unit (HIU) Service & Maintenance

Our service plan will help keep your HIUs in tip-top condition, keeping your heating and hot water in good working order. All our Heat Interface Unit services are fully tested in line with the manufacturer’s instructions. We recommend that your HIU is serviced and tested on a regular basis.

Please contact us for help and advice regarding your Heat Interface Unit Service and maintenance requirements.

Our Customer Promise

Our customer promise to you is that we supply a quality service at a sensible price, our quality control ensures all workmanship and parts supplied and fitted by us come with a 12-month guarantee. take a look at our review page and read what our customers are saying.

Heat Interface Unit Repairs

If a problem strikes, you can count on our team of experts to get your heating and hot water back up and running as quickly as possible. Our manufacture trained HIU Engineers carry spare parts on their vans so they can assist you with a speedy repair. Our technicians can repair all makes and models of Heat Interface Units, so rest assured you are in safe hands with us. 

The Smart Option for Central Heating Controls

With your new Smart Call Heat Interface Unit installation, we offer you the option for total control of your heating, helping you to keep your bills low. We supply and install smart Heating controls such as NEST, Honeywell programmable room thermostats. Hive Heating Controls and Wolseley Programmable room thermostats.

Heat Interface Unit Design and Installation 

Here at Smart Call in London we supply and install various models of Heat Interface Units to suit all your hot water and heating requirements.  For complete piece of mind all our Heat Interface Units come with a minimum of a two-year warranty, with the option to extend. You can also choose one of our maintenance plans that can be tailored for all your requirements. 

If your HIU is old and tired, beyond economical repair or you just want to upgrade, then please contact us. We offer a free consultation service and will be only too pleased to carry out a site or home visit and specify the correct HIU for all your heating and hot water requirements.

Information About Smart Thermostats and
How They Can Save you Energy


A NEST thermostat learns the temperatures that you like when you are at home and then programs itself. It automatically turns down the heating when you are away to help save energy. 

NEST learns from you and programmes itself. You don’t have to programme a NEST thermostat. Just change the temperature whenever you like during the first few days after it has been installed. It will get to know the temperatures that you like and when you want them. Then it programmes itself and creates a weekly temperature schedule.


Your heating in is your hands and being able to control your heating from your phone is really useful. It means you can control it from wherever you are. Or turn it up from the sofa when you’re settling down for the evening. Just having that easy control whenever you need it gives you peace of mind.

Hive thermostat works perfectly with Amazon Alexa and Google Assistant. So, if you want to turn up the heating just say so. With the Hive Thermostat you can set schedules really easily from your smartphone. However, if things change, just move on to the next step in your schedule with a tap of the app. If you leave the house with the heating on, geolocation sends you a reminder to turn it off. It also lets you know if your home is colder than usual when you are returning.


The DT92E wireless digital room thermostat has been designed to provide automatic temperature control underfloor heating, electric heating and zoning systems.  

The DT92E has an ECO button energy saving feature which gives timed setback or boosts temperatures to reduce energy demand. This is a TPI (Time Proportional & Integral) control product which make boilers and heating operate more efficiently and provides close, accurate control. This is continually improved by a self-learning adaptive capability. 


The Wolseley 7 Day Programmable Room Thermostat provides efficient and automatic control of domestic heating systems. Designed from the ground up, this thermostat combines a wealth of features with intuitive heating time and temperature control, making it an excellent choice for a huge variety of domestic dwelling applications.

The thermostat features adaptive control technology which maintains the internal temperature of the home by matching the heating system, the thermostat automatically adjusts the flow temperatures to match the system demand; maintaining room temperatures at the required level. This feature increases system efficiency.  

Heat Interface Unit Energy Meters and Water Meters

We supply and Install replacement energy meters for all Heat Interface Units. The GE552 meter is used for the direct measurement of energy consumption in centralised systems. they measure the heating energy used so you are in control of your energy usage and your bills.

Please contact us if you require more information about our Heat Interface Energy Meters

Additional Information About Heat Interface Units

Heat interface Units (HIU) provide central heating and domestic hot water. The hot water can be created directly using a twin plate or single plate unit. They will serve Individual properties within a multi dwelling development serviced by a centralised heating plant.

Overview of District and Community Heating and Hot Water

District heating supplies heat from a central source to a variety of buildings which might include houses, blocks of flats or apartments. The heat is delivered through a network of pipes carrying hot water. Communal heating follows the same principal but on a smaller scale, sometimes serving a single block of residential flats or apartments.

The energy consumed by an HIU for individual households or apartments is recorded by a meter which makes them very attractive for those operating a large portfolio of developments or single dwellings. Meter readings can even be carried out remotely, making HIUs a much more viable option for landlords, who can then bill their tenants. Metering can also be a positive incentive for occupants trying to lower their energy consumption and to keep their energy bills low

Benefits of Heat Interface Units and Communal Heating

The UK’s 2050 net zero target — one of the most ambitious in the world — was recommended by the Committee on Climate Change, the UK’s independent climate advisory body. Net zero means any emissions would be balanced by schemes to offset an equivalent amount of greenhouse gases from the atmosphere, such as planting trees or using technology like carbon capture and storage

District heating systems are ideal for helping to meet these targets. A well-designed heat network can be very energy efficient, especially when in combination with a high efficiency CHP boiler. Industry waste heat can help reduce the overall energy demand by enabling each dwelling to be metered individually.

Here are Some of the Areas we Cover:

Smart Call PH are a leading heat interface company serving a wide area of London including Putney, Battersea, Wandsworth, Wembley, Brentford, Acton, Greenwich, Bermondsey, Enfield, Tottenham Hale Hampstead Mill Hill, Highgate, Fulham, Chiswick, Hammersmith and much more.