Each year a large overhaul is done with regards to the boilers and flue gas systems at Klemetsrud and Haraldrud plants. Fortum Oslo Varme plan to enter into agreements for yearly boiler and flue gas overhaul, including cleaning (optional).

The areas subject to these contracts are waste to energy boiler lines 1, 2 and 3 at Klemetsrud and the industrial waste to energy boiler line at Haraldrud (K5). Each line is required to have cleaning, inspection and overhaul services with regards to the boiler and flue gas system.