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Focus on Boiler Plus

18/04/2020

 

What is Boiler Plus? How does it relate to my boiler?

Boiler Plus attempted to improve the minimum efficiency standard of gas boilers by requiring an advanced energy saving measure with all new combi boilers. The legislation requires either an advanced heating control or a flue gas recovery unit to be fitted with new combi boilers and time and temperature controls to be fitted with new system and heat only boilers.

Advanced heating controls for combi boilers are split into three groups - load compensation, weather compensation and automation and optimisation controls. Load and weather compensation controls can deliver the highest efficiencies, but only if they speak the same language as your boiler. We help you make sure your boiler and heating control are compatible and present suitable advance controls side by side and help you find the right one for your new or existing boiler.

QUICK GUIDE SUMMARY

Advanced heating controls:

Under Boiler Plus all new combi boilers must be fitted with what are termed ‘advanced heating controls’. Compensation controls must be compatible with your preferred boiler otherwise an ‘optimisation’ control. We guide you here.

Find the right control for your new boiler.

Use our compatibility guide and product comparison tables to find the right advanced heating control for your system.

Improving efficiencies of old boilers:

If you have an on/off boiler then you can use a TPI control or a control with optimisation features to improve efficiencies. We show you suitable products.

How to use this guide

Understand Boiler Plus

Ensure compatibility

Advance heating controls by brand

Options for older boilers

New Boiler Plus requirements

Under the new Boiler Plus requirements, a new combi boiler must be fitted with an advanced temperature control that uses: 1) weather compensation, 2) load compensation or 3) smart controls with automation and optimisation functions (each control type is discussed below). The new regulations vary for heating only and system boilers and existing installations, as follows:

New installations of a combi boiler:

require a programmable room thermostat with an ‘advanced’ energy saving feature, i.e. weather compensation, load compensation or smart controls that combine automation and optimisation features.

New installations of a heat only or system boiler:

require a programmable room thermostat or a thermostat with separate programmer. You can still opt to install an advanced control and we guide you compatibility.

Existing boiler installations:

have no minimum requirement for heating controls. You can replace your room thermostat with another room thermostat and nothing more. Again you can opt for an advanced control or may wish to have the functionality of an internet control and we guide you suitable products below.

1) Weather compensation controls

Weather compensation controls estimate how much heat the boiler needs to produce based on the difference between the external temperature and the desired internal room temperature. Weather compensation controls can work with compatible ‘modulating’ boilers. A modulating boiler operates between a range of outputs, for example between 5kW and 18kW. The thermostat adjusts the boiler’s output up or down as weather conditions change. This ‘advance warning’ allows the boiler to make small adjustments to its output in order to meet the heat demand as efficiently as possible.

The outside temperature is either obtained via an externally fitted probe or via the local weather station. Temperature data from a weather station will be less accurate than a probe fitted to the outside of the house. For this reason weather station compensation thermostats tend to work in conjunction with load compensation technology.

2) Load compensation controls

Load compensation works in the same way as weather compensation, but instead uses the difference between the internal room temperature and the desired room temperature to control the boiler’s output to close the gap. Load compensation can work with compatible modulating boilers.

For compensation controls to work the heating control and boiler must be able to communicate in a common language – see our Ensuring Compatibility section below.

3) Smart controls featuring automation and optimisation functions

Weather and load compensation vary the boiler’s output to use as little gas as is absolutely necessary to meet the desired room temperature. Smart controls, for the purposes of Boiler Plus, use AI to automate the time and temperature settings based on occupancy detection, geofencing and/or stored data from user patterns over time. Smart controls work on a learned schedule of use and how quickly your home loses or gains heat. Over time the control will know how early the boiler will need to come on to meet the set temperature operating in its most efficient condensing mode.

Ensuring compatibility

Weather and load compensation controls need to use the same ‘language’ as the boiler in order to operate, this is referred to as the ‘communication protocol’.

In a recent study from the BRE, it was reported that of 28 compensating heating controls reviewed, 74% used a language unique to the boiler manufacturer, i.e. only the boiler manufacturer’s compensation controls would work with their boilers. 26% used ‘Opentherm’. Opentherm is a common language used my different boiler and control manufacturers to make their products compatible.

What does this mean for consumers? It means that the number of compensation control products that will work with a specific boiler is limited. You will need to choose either the boiler brand’s own control, choose an Opentherm control and an Opentherm boiler or opt for smart controls with automation and optimisation functions. We guide you below:

Find the right advanced control for your system

Remember, it is only mandatory to fit an advanced heating control on a new combi boiler. However owners of older boilers or those having a new system or heat only boiler fitted may still want to benefit from the energy savings of advanced heating controls and the convenience of internet controls. For those energy savings to be maximised however you must pick a compatible compensation control or go with a useful alternative, as follows:

Options for new combi boilers

  • Pick the boiler manufacturer’s smart control and compatible boiler.
  • Pick a boiler and control that both use Opentherm protocol – see our Guide to Opentherm boilers and controls for more.
  • Pick a smart control with optimisation features such as Nest or Tado.

Options for new heat only or system boilers:

  • Pick the boiler manufacturer’s smart control and compatible boiler – Worcester, Vaillant and Glow Worm manufacturer smart controls that include hot water controls.
  • Pick a boiler and control that both use Opentherm protocol – see our Guide to Opentherm products for more.
  • Pick a smart control with optimisation features such as Nest or Tado.

Options for existing modulating combi boilers under 20 years old:

  • Check to see if the manufacturer’s smart control is compatible with your old boiler.
  • Check to see if your old boiler uses the Opentherm protocol - see our Guide to Opentherm products for more.
  • If all else fails, pick a smart control with optimisation features such as Nest, Tado or Danfoss TPOne

Options for older on/off boilers

  • Pick a smart control with optimisation features such as Danfoss TPOne, Nest or Tado.
  • Pick a control with TPI (see product comparison tables below)

Advanced heating control product comparison

The table below shows a selection of standard and smart controls with advanced heating control technologies from third party manufacturers and boiler branded models (for the full range of internet controls go to our Guide to Smart Heating Controls). The two Honeywell controls, Nest and Tado are all Opentherm and can be used with Opentherm boilers (see our Guide to Opentherm boiler and controls). The Tado, Nest and Danfoss controls all use optimisation features that can work to optimise most boilers, including older boilers and heat only and system boilers.

7 day programmers

Wireless thermostats with programmers (non smart control) Honeywell T4R 7 day programmable thermostat Myson Touch programmable room thermostat Danfoss TPOne-RF programmable room thermostat Nest thermostat E Honeywell Lyric T6 Wireless Smart Thermostat Tado smart thermostat Starter Kit V3+ Worcester EasyControl (replaces the Worcester Wave). Vaillant Vsmart
 
Price £127.00 £109.00 £135.00 £199.00 £204.00 £200.00 £210.00 £160.00
Display Digital Touch screen Digital Touch screen Touch screen Touch screen Touch screen Touch screen
No of days 7 day No 7 day 7 day 7 day 7 day £132 integral gas valve Different vSMART controller
Smart phone app No Yes No Yes Yes Yes £332.00 £225 for vSMART control with hot water function
Combi only or all boiler types All boiler types Heat only and system All boiler types All boiler types All boiler types All boiler types Combi Greenstar i range: Junior, Si, CDI compact and Cdi Classic. System Greenstar: 12i-24i, 27i-30i and Cdi Classic System All Vaillant ecoTEC boilers
Integal hot water control No Yes No Yes Yes Yes Yes Yes
Heat zone capability 1 heating zone 1 + hot water 1 heating zone 2 + hot water 1 heating zone 1 heating zone 1 + hot water (with diverter valve) 1+ hot water for vSmart with hot water function)
Weather compensation, load compensation or smart automation and optimisation Load and weather compensation (T4M) Load Smart automation and optimisation Load compensation and smart automation and optimisation Load compensation Weather compensation and Smart automation and optimisation Weather and load compensation Weather and load compensation
TPI software 'Fuzzy logic' Yes Yes Yes 'Fuzzy logic' Yes Yes Yes
Compatible with Smart TRVs No No No Yes - Energenie No Yes - Tado Smart TRVs Yes - Bosch Smart TRVs Yes - AmbiSENSE Smart TRVs
OpenTherm Yes No No Yes Yes Yes (with extension kit) No No
Boiler Plus compliant for combis? Yes Yes Yes Yes Yes Yes Yes Yes
Boiler Plus compliant for heat only and system? Yes Yes Yes Yes yes Yes Yes Yes
Warranty 1 year 2 year 1 year 2 years 1 year 2 year 8-10 years when fitted with a new Worcester boiler 2 years

 

More detail on standard controls and TPI Controls

Standard temperature controls

A standard thermostat turns the boiler on and off to meet the desired room temperature. If the desired temperature is set at 20 degrees, then the thermostat will give the signal to the boiler to switch off at 20 degrees. In this scenario, the boiler maintains its output right up until the point that the thermostat tells it to stop. This means that the temperature of the water in the radiators will continue heating the room to 21 or 22 degrees. In other words, the boiler stays on for longer than necessary, which is very inefficient. It also means that room tends to get too hot and then too cold.

Forms of advanced heating control work to try and prevent this by reducing the boiler’s output as it reaches the set room temperature or turning the boiler off sooner. In order for the an advanced control to reduce the boiler’s output, the boiler must be ‘modulating’ (see below) and the control must be compatible with it (see load and weather compensation controls above).

On/off boilers and modulating boilers

If you are buying a new boiler it will be modulating. If your boiler is over 20 years old then it will likely be on/off but the only way to be sure is to ring the manufacturer’s technical helpline. Which boiler you have will determine the compatibility of the boiler with advanced heating controls.

On/Off boilers

These tend to be older models over 20 years old. On/off boilers fire at the same output, for example a 15kW boiler will always fire at 15kW. A standard thermostatic control will switch the boiler on and off as required, but it is inefficient. The only way to improve the efficiency of these boilers is to more tightly control the times they are on.

Modulating boilers

Most modern boilers are ‘modulating’. This means that they can adjust their output up and down between a range of kW outputs. For example, a 15kW rated boiler can adjust its output to fire between 3kW and 15kW. Modulating boilers are far more efficient because they can reduce their output as demand falls. However to achieve their maximum efficiency they must work with a compatible load or weather compensation heating control.

Time Proportional and Integral (TPI) controls

TPI controls can be used with on/off boilers and heat only and system boilers. As an on/off boiler cannot reduce its output, the TPI control compensates by using historic data to estimate how much time the boiler has to be on to reach the desired room temperature. The TPI control with proportionally reduce the amount of time boiler must be on to meet a lower output. For example, if in autumn only 5kW of heat is required from a 15kW boiler to meet the desired room temperature, i.e. one third of its output, then a TPI control will bring the boiler on for one third of the time, i.e. 20 minutes in an hour.

TPI thermostats

The table below shows a selection of four standard and four internet thermostats that use TPI technology. These are a good option for older on/off boilers and heat only and system boilers. If you want the functionality of an internet control for an old on/off boiler, pick one that uses TPI that can be enabled over other advanced heating control features.

wireless thermostats with programmers (non smart control) Honeywell T4R 7 day programmable thermostat Honeywell RF2 Sundial Pack 2 wireless programmable room thermostat Danfoss TPOne-RF programmable room thermostat Neomitis 1 day programmable room thermostat RT1 RF Nest thermostat E >Honeywell Lyric T6 Wireless Smart Thermostat Siemens RDS110 Tado smart thermostat Starter Kit V3+
 
Price £127.00 £160.00 £135.00 £72.00 £199.00 £204.00 £155.00 £200.00
Display Digital Digital Digital Digital and Dial Touch screen Touch screen Touch screen Touch screen
No of days 7 day 7 day 7 day 1 day 7 day 7 day 7 day 7 day
Smart phone app No No No No Yes Yes Yes Yes
Combi only or all boiler types All boiler types Heat only and system All boiler types All boiler types All boiler types All boiler types All boiler types All boiler types
Integral hot water control No No No No Yes Yes Yes Yes
Heat zone capability 1 heating zone 1 or 2 + hot water 1 heating zone 1 heating zone 2 + hot water 1 or 2 heating zone 1 heating zone 1 heating zone (more with smart TRVs)
Weather compensation, load compensation or smart automation and optimisation Load Load Smart automation and optimisation Neither Load compensation and smart automation and optimisation Weather and load compensation Load compensation Smart automation and optimisation
TPI software Yes 'Fuzzy logic' Yes Yes Yes 'Fuzzy logic' Yes Yes
OpenTherm Yes Yes No No Yes Yes No Yes
Boiler Plus compliant for combis? Yes Yes Yes No Yes Yes Yes Yes
Boiler Plus compliant for heat only and system? Yes Yes Yes Yes yes Yes Yes Yes
Warranty 1 year 1 year 1 year 3 years 2 years 1 year 1 year 2 years

Jo Alsop

Heating Hero

The Heating Hub

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