There’s also a deadline built into that calculation. Bitcoin’s next halving, which is expected in spring 2028, will cut the amount of new bitcoin awarded to miners in half. That could happen well before homeowners recover the cost of their heating systems, potentially throwing a wrench in the pitch for the Bitcoin Boiler.
SunBit, which delivered its first production batch of Bitcoin Boilers in 2025, now has 30 systems running, founder and CEO Elmeri Suomi told CoinDesk this week. All but one are in Finland, and between them they have replaced or cut back on gas, oil, wood and district heating.
At a commercial property in Lekkum, in the Netherlands, SunBit’s first export project in 2025, a miner replaced gas heating. In Kotka, a port city of about 50,000 on Finland’s southeast coast, a 200-square-meter house runs one alongside its existing oil boiler as a hybrid system.
At an old manor house in Tampere, Finland’s third-largest city, mining replaced wood heating, and the miner keeps a 1,500-liter water tank at 50°C to 60°C. A 3,000-square-meter industrial hall in Vimpeli runs one alongside an air-to-water heat pump, and it soaks up surplus power from a 30-kilowatt solar array.
Finland is already the testbed for heating with mining. MARA’s systems feed waste heat from its miners into district heating networks in Satakunta and Seinäjoki, warming about 80,000 residents.
