Regulation 811/2013, as retained in Great Britain, sets energy labelling rules for space heaters and combination heaters up to 70 kW, which covers ordinary domestic gas boilers. It places duties on suppliers, on dealers and on anyone advertising a specific model, and it defines the efficiency classes printed on the label. This guide summarises the text on legislation.gov.uk as it stood in September 2026 and does not cover Northern Ireland.

What the Regulation covers

Article 1 says the Regulation establishes energy labelling requirements, and requirements for supplementary product information, for space heaters and combination heaters with a rated heat output of 70 kW or less. It also covers packages that combine a heater with temperature control and a solar device. Article 1(2) excludes several categories, including heaters using solid fuels, heaters generating heat only for hot drinking or sanitary water, and heaters for distributing gaseous heat transfer media such as vapour or air.

The efficiency classes on the label

Annex II sets the classes. For space heating, Table 1 runs from A+++ at a seasonal efficiency of 150% or more down to G below 30%. The band for class A is 90% or more but under 98%, class B is 82% to under 90%, class C is 75% to under 82%, and class D is 36% to under 75%. Class A is not the top of the scale, since A+, A++ and A+++ sit above it. Table 2 uses different thresholds for low-temperature heat pumps and heat pump space heaters for low-temperature application, so classes cannot be compared across heater types without checking which table applies. The guide to boiler efficiency ratings explains how the bands relate to running costs.

A combination heater also carries a water heating class. Table 3 in Annex II gives thresholds for each declared load profile, from 3XS to XXL, so a combi is graded for hot water against the profile it declares.

What suppliers must provide

Article 3 places the first duties on suppliers, meaning those who place heaters on the market or put them into service. From 26 September 2015 a supplier must provide a printed label for each space heater and a product fiche, make an electronic label and electronic fiche available to dealers, and supply technical documentation to the authorities of Great Britain on request. Article 3(2) applies the same approach to combination heaters, with a label showing both the space heating and water heating classes. Article 3 also provides for a printed label in the format of point 1.2 of Annex III from 26 September 2019, and point 2.2 for combination heaters.

What dealers must do

Article 4 covers dealers. Each space heater at the point of sale must bear the supplier’s label on the outside of the front of the appliance, in a clearly visible way. Where a heater is offered for sale, hire or hire-purchase and the customer cannot be expected to see it displayed, the offer must be marketed with the information from the supplier, and Annex IX applies where the offer is made through the internet.

Article 4(3) deals with packages of heater, temperature control and solar device. Any offer for a specific package must include the seasonal space heating efficiency and class for the package, shown by displaying the package label and providing the completed fiche. The role of controls is explained in the guide to heating controls.

Advertisements and promotional material

Articles 3 and 4 both require that any advertisement for a specific model that contains energy-related or price information includes a reference to the seasonal space heating efficiency class under average climate conditions. For a combination heater, the reference must include the water heating class as well. The same requirement applies to technical promotional material that describes the specific technical parameters of a model. A leaflet or web listing showing a boiler price and running costs without the class therefore falls short of the Regulation as written.

Enforcement and how to use the label

Article 5 requires the label information to be obtained by reliable, accurate and reproducible measurement and calculation methods, and Article 6 says the authorities of Great Britain apply the verification procedure in Annex VIII to check the declared classes and efficiency. When comparing quotes, the label and fiche give a like-for-like basis for the model, as covered in the guide to comparing installation quotes. The separate minimum efficiency floor for new boilers is in the guide to ecodesign rules for new gas boilers.

FAQs

Does every boiler have to carry an energy label?

Regulation 811/2013 applies to space heaters and combination heaters with a rated heat output up to 70 kW, subject to the exclusions in Article 1(2), such as solid fuel heaters and water-only heaters.

Where must the label be shown in a shop?

Article 4 says it must be on the outside of the front of the appliance at the point of sale, in a clearly visible way.

Must a boiler advert state the efficiency class?

Yes, where the advert relates to a specific model and contains energy-related or price information, Articles 3 and 4 require a reference to the seasonal space heating efficiency class for that model.

The bottom line

Under Regulation 811/2013 as retained in Great Britain, suppliers must provide a label and fiche for boilers up to 70 kW, dealers must display the label on the appliance at the point of sale, and adverts for a specific model that give energy or price information must state its efficiency class. Packages with controls carry a package rating. This is general information, not regulated advice on any specific installation.

Sources

This guide draws on the following primary sources, current as of 25 September 2026:

• legislation.gov.uk, “Commission Delegated Regulation (EU) No 811/2013, Article 1: Subject matter and scope”
• legislation.gov.uk, “Commission Delegated Regulation (EU) No 811/2013, Article 3: Responsibilities of suppliers and timetable”
• legislation.gov.uk, “Commission Delegated Regulation (EU) No 811/2013, Article 4: Responsibilities of dealers”
• legislation.gov.uk, “Commission Delegated Regulation (EU) No 811/2013, Annex II: Energy efficiency classes”
• legislation.gov.uk, Commission Delegated Regulation (EU) No 811/2013, Article 5
• legislation.gov.uk, Commission Delegated Regulation (EU) No 811/2013, Article 6

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Best Boiler Deals is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not regulated advice on any specific installation — always confirm the details with a Gas Safe registered engineer.