This open letter addresses the misclassification of waste incineration’s heat output as ‘waste heat’ within the Renewable Energy Directive (RED) framework in the EU. It highlights the negative environmental impacts of waste incineration, including greenhouse gas emissions and disincentivizing waste prevention and recycling efforts. We advocate for the exclusion of waste incineration from ‘waste heat’ targets, emphasising the importance of prioritising genuine renewable energy sources like heat pumps and solar thermal for district heating. It urges policymakers to prioritise waste prevention, recycling targets, and investment in innovative clean energy technologies to achieve a truly sustainable energy future.