The outcome of protecting the rights and legitimate interests of participants in the heat supply sector depends entirely on the consequences that arise in connection with the application of a specific method of protecting rights. The paper examines the main and additional consequences of unjust enrichment in relation to one of the key areas of energy — heat supply. The problems of applying unjust enrichment rules are demonstrated, and the contentious nature of the issue regarding the moment of calculating interest for the use of other people’s funds is emphasized. The author criticizes approaches to the allocation of the burden of proof and suggests considering an objective criterion for the possibility of using the awarded amount in economic activity (with due regard to the specifics of the heat supply sector). The indexation mechanism is considered an additional consequence of unjust enrichment (condictio claims), interest in which is objectively increasing due to the need to protect the claimant’s funds from inflationary processes amid uncertainty in the application of procedural rules. It is argued that the indexation of funds is impossible without considering the economic substance and legal nature of the claims that led to their award.