A house in Nokia, Finland, dropped district heating for a bitcoin miner

The owners of a 180 m² house in Nokia, the Finnish town that gave its name to the phone maker, have disconnected it from district heating. A bitcoin miner in the basement now heats the whole building, CoinDesk reported on 8 November. It is one of 30 homes and businesses that use bitcoin mining heating from the Finnish company SunBit.

How a miner becomes a boiler

Mining hardware turns almost all the electricity it uses into heat. A normal data centre pays to get rid of that heat. SunBit's Bitcoin Boiler keeps it.

The system runs one water-cooled Bitmain Antminer S21 XP Hydro. It draws about 5.3 kW around the clock, roughly 46,400 kWh a year, and every kilowatt-hour comes out as heat. Water carries it at up to 60°C into the radiators and floor pipes, so the miner takes the old boiler's place. Some owners add a buffer tank: a manor house in Tampere keeps 1,500 litres at 50 to 60°C.

In summer a dry cooler outside, a radiator with fans, throws away the heat the house cannot use. Over a year more than half of the heat never reaches the rooms.

Who pays for the power

The owner buys the machine, pays for the electricity and keeps the mined bitcoin. SunBit quotes about $20,200 for a basic installed system, and its founder Elmeri Suomi gives a range of $20,400 to $31,400 with payback in three to six years. SunBit keeps a 10% service fee, and the mining pool takes about 0.5% more.

With power at about 11 cents per kWh, the miner earned about 13 cents per kWh on SunBit's assumption of a bitcoin price near $82,000. So the heat comes out as a by-product that pays for itself. SunBit puts the owner's break-even just under $70,000.

“The trade-off is that the economics depend on Bitcoin price and network difficulty, which a heat pump doesn't.”

— Elmeri Suomi, SunBit

Quote source: CoinDesk, 8 November 2026.

The margin is already thin

Bitcoin traded near $73,700 on Wednesday, CoinGecko data show. That leaves about 5% above SunBit's break-even, by our calculation, instead of the 15% the company modelled.

Halving is the bigger risk. In spring 2028 the block reward falls from 3.125 to 1.5625 BTC. With all other inputs fixed, mining income would drop to about 7 cents per kWh, below the price of power. To keep the heat free after the cut, bitcoin would need to trade above roughly $131,000. A house that installs a boiler this winter has about 18 months at current margins. Large miners face the same squeeze, and some, such as Core Scientific, are leaving mining for AI data centres.

Compare it with a heat pump. A heat pump gives 2.5 to 3 kWh of heat for each kWh of power and does not care about the bitcoin price. For a house that needs 25,000 kWh of heat a year, CoinDesk puts the running cost at about $1,100 with a heat pump against about $3,170 for district heating.

Other SunBit sites mix bitcoin mining heating with other sources. A 200 m² house in Kotka runs the miner next to its oil boiler, and a 3,000 m² hall in Vimpeli pairs one with a heat pump and 30 kW of solar panels. On a larger scale, MARA feeds miner heat into district networks in Satakunta and Seinäjoki that warm about 80,000 people.

If you consider a setup like this, run the numbers for your own power price and plan for the 2028 halving. Track the bitcoin price against a break-even near $70,000, and keep a backup heat source for a weak market.

Costs, revenue and the break-even price come from SunBit's own calculator and statements as CoinDesk reported them, and nobody has checked them independently. Mining income also depends on network difficulty. This is news, not investment advice.