The linked article touches upon that concept as a feasible application of mining heat:
"In a home, however, if the outside temperature is less than about 20′C, the cost of electricity is zero; all electricity spent by the miner necessarily eventually turns into “waste” heat, which then heats the home and substitutes for electricity that would be spent by a central heater."
The zero-cost figure is... um... wrong. Your central heater probably either does not use electricity (presumably using a cheaper fuel source) or is a heat pump (and thus gets efficiency greater than 100% on the electricity by stealing heat from the ground). The real cost is still lower than the nominal cost, but it's not zero.
"In a home, however, if the outside temperature is less than about 20′C, the cost of electricity is zero; all electricity spent by the miner necessarily eventually turns into “waste” heat, which then heats the home and substitutes for electricity that would be spent by a central heater."