The ErP energy label is the EU efficiency label for heating products, created by Regulations 811/2013 and 812/2013 under the Ecodesign framework. Space heaters are rated on a scale reaching A+++, water heaters up to A+, and hot water storage tanks from A+ to F based on standing loss in watts. Every heater and cylinder sold in the EU must carry one.
What is the difference between Ecodesign and the energy label?
They are two halves of one system. Ecodesign Regulations 813/2013 (space heaters) and 814/2013 (water heaters and tanks) set minimum efficiency requirements a product must meet to be sold in the EU at all — the floor that effectively removed non-condensing gas boilers from the market. Energy Labelling Regulations 811/2013 and 812/2013 then rank the products that clear the floor, on the coloured A-to-G-style scale consumers recognise from refrigerators.
ErP stands for Energy-related Products, the umbrella directive behind both. In trade shorthand, Ecodesign decides what may be sold; the ErP label decides how it compares.
How are heaters classed on the ErP label?
Space and combination heaters are classed by seasonal space heating efficiency — ηs — measured across a whole heating season rather than at a single test point. The scale for space heating has extended to A+++ since 2019, and the technology gap is stark: condensing boilers cluster around class A, while heat pumps typically reach A++ or A+++ because one unit of electricity moves several units of heat, as captured by the SCOP.
| Product | Regulation | Label scale | Basis |
|---|---|---|---|
| Space/combination heaters | 811/2013 | Up to A+++ | Seasonal efficiency ηs |
| Water heaters | 812/2013 | Up to A+ | Load-profile efficiency |
| Hot water storage tanks | 812/2013 | A+ to F | Standing loss (W) |
| System packages | 811 & 812/2013 | Up to A+++ | Combined calculation |
Water heaters are rated against declared tapping load profiles (from 3XS to XXL), so two units carry comparable figures only when tested on the same profile.
How are hot water tanks classed?
Storage tank classes translate one number: standing loss, the watts a tank leaks to the room while holding temperature. Class boundaries are formulas of tank volume, so a 300-litre tank is allowed more watts than a 150-litre one within the same class. Insulation thickness and quality decide the outcome almost single-handedly — moving a cylinder one class down can roughly halve its annual standing losses, which for a typical family cylinder is worth hundreds of kWh per year. Solimpeks rates its Solibuffer and DHW tank ranges (50–1,000 litres) under exactly this scheme.
What does the ErP label not tell you?
The label is deliberately narrow, and for cylinders it hides most of what determines real-world performance. A tank's class says nothing about coil surface area — which sets whether a heat pump can charge it efficiently — nothing about recovery rate, nothing about stratification quality, and nothing about corrosion protection or service life. Two class-B cylinders can behave completely differently on a heat pump. The buying logic beyond the sticker is unpacked in Which cylinder energy class should I buy?.
Package labels work in the buyer's favour: installers must produce a combined label when selling a heater with controls, solar devices or a tank, and adding certified solar thermal input can lift a package one or two classes above the heater alone. The calculation uses standard assumptions, so the real gain depends on your roof and hot water demand.
Does the ErP label apply outside the EU?
The EU regulations bind the EU market plus EEA states, and the UK retained a near-identical ErP regime after Brexit, so the same label logic applies. Exporters certify once per regime: as a manufacturer shipping to 96+ countries, Solimpeks documents ErP data for European markets alongside Solar Keymark and SRCC certification for collector performance — different schemes answering different questions.
Frequently asked questions
What does ErP stand for?
Energy-related Products — the EU framework directive covering products that use or influence energy use. For heating, its Ecodesign regulations set minimum efficiencies and its Energy Labelling regulations create the familiar coloured label.
Why do heat pumps get A++ or A+++ while boilers only reach A?
The label ranks seasonal efficiency, and a boiler cannot exceed roughly 100% — every kWh of heat needs a kWh of fuel. A heat pump moves three to four kWh of heat per kWh of electricity, so its seasonal efficiency lands in the 125%+ territory the A++ and A+++ classes were built for.
What is a good ErP class for a hot water cylinder?
Class B or better is a sensible target for a new cylinder; class C is common in standard products. The class reflects standing loss only, so also check coil area and recovery rate — especially for heat pump systems, where the coil matters more than the sticker.
What is a package label?
When a heater is sold together with controls, a tank or solar devices, the installer must calculate and present a combined label for the whole package. Solar contribution and smart controls can raise the package class above the heater's own rating.