Basic Boiler-Radiator system with Single Thermostat

Intelligent Heating - Radiator Boiler

The traditional Basic Boiler- Radiator system provides hot water and heating in many homes in the UK and Europe.

The system uses a central boiler to heat the water, a pump then circulates this through radiators situated around the house. The overall temperature is regulated by a single wall thermostat that is typically positioned in the coolest part of the house, most often the hall. A timer controls when the boiler and pump are activated, so that you can choose when the heating system is On.

The boiler also produces hot-water to be used for bathing or washing - depending on the type of boiler system you have this can be 'on-demand' or stored in a hot-water cylinder.

This type of Basic system is quite simple, but this simplicity also means that it can be quite inefficient.

Boiler and Heating Types

There are three main types of heating system in common use, it's best to know which one you have before investigating how to control it with home automation:

  • Combi boiler
    This type is becoming increasingly common. It provides heating based on the timer/controller and provides instantaneous hot-water 'on-demand'. The timer is a single channel type as there is no need to control the hot-water.
  • Y-Plan system
    This is probably the most common system in the UK. The boiler provides heating based on the timer, and heats hot-water to be stored in a hot-water cylinder; also controlled by the timer. It includes a single motorised valve that sends heated water to either the hot water tank, the heating or both. The timer is a 2-channel type to allow the heating and hot-water to operate independently.
  • S-Plan system
    This is very similar to the 'Y-plan' system, but uses two motorised valves, one regulating the supply for the hot water and one for the heating.

Add Home Automation to Control Your Heating

Adding home automation to control this type of Basic Boiler-Radiator heating system is quite straightforward. You replicate the basic functionality of the thermostat and boiler control with Z-Wave devices. This enables the system to run in exactly the same way as it always has, but gives you further refinement to save you money. You can have wireless control of the system, so you can easily make adjustments. You can create intelligent 'Scenes' to manage the heating more efficiently, and you can control it whether you are at home or away - so if you're going to be late home, you can delay the heating turning on. These refinements give you a more convenient heating system and will save you money.

How it works

The home automation system replaces the functionality of the current timer and thermostat with Z-Wave devices. The Thermostat and Boiler Receiver control your heating based on a schedule 'Scene' running in the Z-Wave Controller which changes the thermostat's set-point temperature at different times of the day. You can also choose a thermostat that has an integrated 7-day timer, so that it runs the heating schedule itself. If you have a Y-plan or S-plan system, the hot-water will be run by a separate schedule 'scene' in the Z-Wave Controller. In this system, the Thermostat and Boiler Receiver are configured to work in Z-Wave Association mode, allowing the thermostat to directly control the receiver without having to communicate via the Z-Wave controller. It also means that the Thermostats's TPI control software is used to efficiently control your heating.

Components - what they do

To add home automation control of your radiator-based heating system, you only need to add three components (less if you already have a Z-Wave system). Below we explain the function of each component and our recommended products.

Boiler Receiver

This is a Z-Wave Switch (Relay) that replaces your existing heating controller/timer. It enables the Z-Wave system to control when the boiler is On or Off. If you have a Combi boiler, you will need a single-channel receiver, if you have a Y-plan or S-plan system you will need a 2-channel receiver or switch as you will also need to control the hot-water system.

  • Secure Single-Channel Boiler Receiver
    Purpose designed Z-Wave Receiver for controlling a Combi boiler. It enables the Z-Wave system to control the boiler and has buttons and LEDs for manual On/Off control.
  • Secure 2-Channel Boiler Receiver
    Purpose designed Z-Wave Receiver for controlling a Y-plan or S-plan boiler. It enables the Z-Wave system to control the boiler and has buttons and LEDs for manual On/Off control of the heating and hot-water.
  • Fibaro Switch 2 (Double)
    Dual relay that can control the boiler's heating and hot-water channels.
  • Qubino Relay x2 Plus
    Double switch (relay) module can control the boiler's heating and hot-water channels.

Wall Thermostats and Sensors

Communicates directly with the Boiler Receiver or Relay to control the boiler (heating) depending on the room's ambient temperature and the 'set-point' temperature you've selected. This allows the system to run the heating system with the optimum efficiency as the thermostat has in-built heating algorithms (TPI) that optimise the boiler On/Off periods. You can change the thermostat's set-point temperature wirelessly, giving you complete control over your heating system.

  • Secure Wall Thermostat (SRT321)
    Wall mounted thermostat controls the boiler (via the receiver) and can have it's set-point changed by the Z-Wave controller. All heating schedules will be run in the Z-Wave controller and the heating's On/Off periods controlled by changing the wall thermostat's set-point. Requires boiler receiver or relay to control boiler.
  • Secure Wall Thermostat (SRT323)
    Similar to the Secure SRT321 thermostat, but does not need a boiler receiver. The SRT323 includes switch contacts allowing it to control the boiler directly via the current wiring.
  • Secure Programmable 7-day Thermostat (SCS317)
    Very similar to the Secure Wall Thermostat (SRT321), except it has an integrated 7-day timer that enables it to run the heating based on schedules you program into the thermostat - it can have up to 6 temperature periods per day. Requires boiler receiver or relay to control boiler.
  • Secure Wall Temperature Sensor
    Wall mounted temperature sensor can report the room's temperature to the 'Scene' running the heating control.
  • Danfoss Temperature Sensor
    Wall mounted sensor sends temperature to Z-Wave controller so that you can use this to control the heating.

Z-Wave Controller

The controller enables you to add and configure devices to your Z-Wave system and run 'schedule scenes'. It also acts as a gateway allowing you to control the system from a smartphone even when you are away from home. In the case of heating, the controller will run the schedules to control when the heating is On/Off and at what temperature, it will also run the hot-water times.

For more information take a look at our How to Choose a Z-Wave Controller Guide.

Home Automation - Z-Wave Controllers Vesternet

Technical Guides

These guides and videos show how these various systems can be integrated with Vesternet's home automation products.


Copyright Vesternet 2018

Updated: 16/08/2018