What is the Boiler Plus Compliance?

Updated: Aug 18, 2021

As of April 2018 new legislation has been brought in to improve the energy efficiency of homes throughout the UK. As part of the 'Heat in Buildings' government programme, boiler plus means that all boilers have to have an ErP efficiency rating of at least 92% in order to be considered compliant. It also

means that all new boiler installs must be completed with both temperature and time controls fitted. The main aim of this legislation is to keep the UK's place as one of the leading global gas boiler markets , whilst decreasing the fuel consumption and lowering the cost of many homes energy bills.

Currently the legislation only applies to boilers installed after the 6th April 2018. For boilers and installs completed prior to this , it is still possible to implement time and temperature control features, with the installation of a smart thermostat such as the NEST.

Additionally, combi boilers will require at least one of the following four features to be fitted:

Load compensation:

This enables the boiler to modulate the flow temperature from the boiler based on the temperature of the room, so if the room was cold the boiler will automatically adjust the flow in order to start heating it up.

Weather compensation:

Similar to load compensation but temperature of the flow is based on the outdoor temperature, instead of the room temperature. The temperature is measured using an outdoor thermometer and based on the reading the boiler will adjust the temperature of the flow to accommodate. This allows radiators to run cooler when less heat is needed, without adjusting them manually.

Smart Control:

A control that provides automation and optimisation. In this instance automation refers to the ability to learn based on the adjustments made by a customer and implement adjustments based on stored data.


Passive Flue Gas Heat Recovery Device. These enable the boiler to reuse heat that would otherwise be wasted. The device works by extracting residual energy from the flue gases released by the boiler, that energy then begins to warm the water that is fed into the Combi boiler, reducing the amount of gas used to heat water to the required temperature. These can be fitted onto most boilers retrospectively in order to meet the requirements of the legislation.

The Mandatory addition of at least one of these features for each new install, means that customers looking to have a new boiler installed will be looking at slightly higher costs to accommodate the labour and materials involved. It also means that every installer will have to have comprehensive knowledge of each feature in order to help the customer come to the decision as to which one is best for them. Despite the initial increase in the price of a new boiler, the fact that they help lower the household energy bills could mean that the money will be made back in savings in the long run. Its a slightly higher outlay (Starting from approximately £50) for long term savings.

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