The regulation does not refer to 'installer', but it does refer to 'dealer'. A package label has to be provided by the dealer defined in the Energy Labelling Regulation as “a retailer or other natural or legal person who offers for sale, hire, or hire purchase, or displays products to customers or installers in the course of a commercial activity, whether or not in return for payment”. If the person installing the product is doing any of these, he/she will be considered the “dealer” and the package label is required.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.