LOT 20 Explained: The Ecodesign Rules for Electric Heaters in the UK
LOT 20 is the nickname for the Ecodesign rules that set minimum efficiency standards for electric heaters sold in the UK. They came in on 1 January 2018 and they still apply today. Here is what they require, what they mean when you buy a heater, and what they do not change.
Key Takeaways
- LOT 20 is the Ecodesign regulation for local space heaters, including electric panel heaters and radiators.
- It has applied since 1 January 2018 and still applies in Great Britain and Northern Ireland.
- It does not ban heaters already installed in your home; it governs what can be sold new.
- In practice, a compliant fixed electric heater needs an electronic thermostat plus timer and other energy saving controls.
What is LOT 20?
LOT 20 was the name of the study group for local space heaters in the EU Ecodesign programme, and the name stuck to the regulation that came out of it (EU Regulation 2015/1188). It sets minimum energy efficiency standards for heaters that warm a single room, such as electric panel heaters, oil filled radiators and portable heaters.
After Brexit the rules were kept in Great Britain under the Ecodesign for Energy-Related Products Regulations, and Northern Ireland continues to follow the EU rules. For anyone buying a heater in the UK, LOT 20 is still the standard.
What does it require?
The regulation measures a heater on its seasonal space heating efficiency. Every electric heater converts electricity to heat at almost 100 percent, so the score is really about control: how well the heater avoids wasting energy by heating rooms that are already warm or empty.
A fixed electric heater with an output above 250W must reach a minimum seasonal efficiency of 38 percent. A basic heater with a mechanical thermostat cannot get there. In practice a compliant fixed heater needs:
- An electronic room temperature control, which holds the set temperature far more accurately than a mechanical dial
- A timer, usually a 24 hour or 7 day schedule
- Often additional features such as open window detection, adaptive start or remote and app control
If a fixed electric heater only has a simple mechanical dial and no timer, it is very unlikely to meet LOT 20. Check before you buy, especially from marketplace sellers importing old designs.
What does it mean for you?
If you are buying a new heater, LOT 20 works in your favour. A compliant heater with an electronic thermostat and a schedule only heats when and where you need it, which is where most of the running cost saving comes from. Our smart heating controls guide explains what each control does.
If you already have older heaters, nothing changes. LOT 20 applies to products placed on the market, not to heaters already installed in homes. You do not need to replace a working heater because of it, though upgrading an old one can cut what you pay to run it.
Landlords and installers fitting new fixed heaters should use compliant models, since it is the product being supplied that has to meet the rules.
Does it make electric heating cheaper?
LOT 20 does not change the price of electricity, and it cannot make a 1000W heater use less than 1kW while it is heating. What it does is make sure the heater switches off when the room is warm and can be scheduled around your day. That is what keeps the real running cost down. For the numbers, see our electric heater running costs guide.
Final thoughts
LOT 20 has been part of buying an electric heater in the UK since 2018. Look for an electronic thermostat and a timer as a minimum, treat bargain heaters with mechanical dials with caution, and you will end up with a heater that is both compliant and cheaper to live with.
Heaters with the controls LOT 20 asks for
ADAX and Sol*Aire panel heaters with electronic thermostats, 7 day timers and app control.