Your home is part of a Communal Heating network.
Instead of having an individual gas boiler in every home, a communal heating system uses a centralised boiler room to provide heat to the whole development.
The Heat/Hydraulic Interface Unit (HIU) in your apartment transfers heat from the central system in to your apartment, and a heat meter measures your heat consumption. A thermostat similar to the kind used in traditional gas heating systems allows you to control the amount of heat you consume.
Heat networks are becoming popular, because it is more energy efficient to have one central source of heat rather than for each home to have its own boiler or heater. Your apartment benefits from being connected to a centralised communal system where you are buying ‘useful energy’ on demand (heat and hot water) rather than ‘raw fuel’ (gas).
Some apartments benefit from centralised chilling as well as centralised heating. This type of system provides cool air to an apartment during the summer months.
In a Communal Heating Network (see What is Communal Heating?) each property in a development is fitted with an HIU and the heat is generated by a large central boiler.
The HIU can usually be found in the utility cupboard of each property, and looks like a large white metal box.
A Heat Interface Unit (HIU) fulfils the same function as a combination boiler providing heat and hot water, but without the need for each property to have a gas supply.
The HIU takes the heat generated by the communal boiler and uses an inbuilt heat exchanger to heat the water in your central heating and cold water supply.
Each HIU is fitted with a heat meter which measures the heat and hot water being used by the property or apartment.
Your apartment will typically have a simple thermostatic control that will allow you to adjust the temperature in your apartment.
Generic dial type thermostats have been used in residential developments for many years.
Usually the temperature is set to 20°C.
There are however many different systems in use, some with advanced features allowing remote access, and you should have received user instructions for these upon occupancy.
You may also have thermostatic radiator valves (TRV) on your radiators which can be adjusted. The higher the number shown on the valve, the higher the temperature and vice versa.
If the problem extends beyond your apartment then this is likely to be a communal issue.
In this instance you should make contact with your concierge, managing/letting agent or housing officer to report the outage.