Heating with an ASIC miner: savings vs an electric heater and which to choose

An ASIC miner heats exactly like an electric heater with the same power draw: it turns 1 kWh of electricity into 1 kWh of heat – and mines at the same time. The net cost of heat from a miner is therefore the electricity price minus the mining revenue per 1 kWh. We calculate with electricity at 4.5 Kč/kWh (indicative, typically the Czech 20-hour D57d tariff; on the standard D02d tariff around 6.4 Kč/kWh, see How much electricity for mining costs). At that price, as of 4 November 2026, 1 kWh of heat costs 3.09 Kč from the Canaan Avalon Mini 3 and 2.89 Kč from the Canaan Avalon Q. The Antminer S21+ Hyd comes out at 2.50 Kč and the Antminer S21e XP Hyd at 2.19 Kč. That is 31–51% less than an electric heater, but a Bitcoin miner cannot beat a heat pump (about 1.50 Kč/kWh) today.

Summary

• All the electricity a miner consumes ends up as heat. Its heating efficiency is 100%, just like an electric heater.
• Net heat cost = electricity price − mining revenue per 1 kWh. For the Bitcoin and Litecoin machines in our range it currently comes to 2.19–3.09 Kč/kWh at 4.5 Kč/kWh.
• Compared with an electric heater, a miner saves a third to a half. A heat pump (1.50–1.80 Kč) and gas (about 2.41 Kč) are cheaper or comparable.
• For a flat, quiet air-cooled machines up to 1.7 kW are suitable. For heating a house or a pool, hydro machines of around 5.5–6 kW with a water circuit and heat exchanger make sense.
• Mining revenue changes with the exchange rate and difficulty. The saving is therefore not fixed, and in summer, when you do not need the heat, it disappears.

How much does 1 kWh of heat from a miner cost today?

At an electricity price of 4.5 Kč/kWh, 1 kWh of heat from a miner costs 2.19–3.09 Kč today, depending on the model. This is how we calculate it:

1. Daily revenue of the machine = hashrate × revenue per unit of hashrate. Today 1 TH/s on Bitcoin earns 0,72 Kč per day (recalculated 4. 11. 2026 8:59).
2. Daily consumption = power draw in W × 24 h / 1,000. The machine delivers the same number of kWh of heat.
3. Revenue per 1 kWh = daily revenue / daily consumption.
4. Net heat cost = your electricity price − revenue per 1 kWh.

Example for the Antminer S21+ Hyd 395 TH/s: 395 × 0.72 Kč = 284 Kč per day. The machine consumes 5.925 kW × 24 h = 142 kWh. So it mines 2.00 Kč per 1 kWh and the heat costs you 4.50 − 2.00 = 2.50 Kč/kWh.

Treat the price of 4.5 Kč/kWh (energy + distribution) as indicative. If you have a different tariff with cheaper electricity, use your own price – the method is the same. Revenues are as of 4 November 2026 and change with the exchange rate and network difficulty.

Which miners in our range are suitable for heating?

Machines from 0.8 to 6 kW are suitable for heating: quiet air-cooled ones for a flat, immersion and hydro ones for heating a house via water. We are a retailer and sell all the machines in the table. Prices are from our website (At home option, incl. VAT), revenues from our hourly recalculation, noise from the machine specifications.

Revenues as of 4 November 2026 8:59, electricity at 4.5 Kč/kWh. For Bitcoin machines (SHA-256) we use 0.72 Kč per 1 TH/s per day. For the Fluminer L1 Pro we use 9.74 Kč per 1 GH/s (Litecoin + Dogecoin, without bonus coins). Noise is not listed in the specifications of immersion machines: they have no fans of their own, so the noise level depends on the circuit's pump and cooler.

Outside the table: iBeLink BM-S3+ 25 TH/s for the BTCB2 coin – high risk. According to our recalculation as of 4 November 2026 (72.67 Kč per 1 TH/s per day), it would mine about 1,817 Kč per day, i.e. more than its electricity costs. Do not take this figure as an expected return. BTCB2 (Bitcoin BLAKE2b) is a young, illiquid coin, and its price and difficulty change much faster than Bitcoin's. In September 2026 the network temporarily froze miners' rewards – see Bitcoin BLAKE2b froze miners' rewards. The machine costs 209,399 Kč, draws 3.4 kW and produces 75 dB, so it is not suitable for a living room without a soundproof box.

We offer a hydro machine with a cooler in one package as mining sets. For example, the mining set Antminer S21+ Hyd 395 TH/s + 12 kW water cooling costs 97,799 Kč, and the set Antminer S19 XP+ Hyd 293 TH/s + 12 kW water cooling 54,799 Kč.

Is a miner cheaper than an electric heater, a heat pump and gas?

Today a miner is 31–51% cheaper than an electric heater, but roughly as expensive as gas and more expensive than a heat pump. Comparison per 1 kWh of heat:

A heat pump produces heat more cheaply because it "pumps" it from the outside air and needs electricity mainly to drive the compressor. According to Bosch Home Comfort, air-to-water heat pumps have an average seasonal COP of 2.5–3. We converted the gas price from the annual costs of a household consuming 25 MWh according to Skrblík.cz (January 2026); the 95% boiler efficiency is our assumption.

For a Bitcoin miner to match a heat pump with a COP of 3, it would have to mine 3 Kč for every kWh consumed. The best in the table, the Antminer S21e XP Hyd, mines 2.31 Kč today.

How much will a miner save over the 2026/27 heating season?

Over 180 days of non-stop operation, the Antminer S21+ Hyd saves about 51,000 Kč compared with an electric heater. The Canaan Avalon Q saves about 11,700 Kč, the Canaan Avalon Mini 3 about 4,900 Kč. The saving compared with an electric heater equals the mining revenue – provided you actually use all the heat.

The calculation assumes that revenue stays at the 4 November 2026 level for the whole season and that the machine runs without interruption. In reality, revenue changes with every difficulty adjustment and with the BTC price. We do not include the price of the machine in the table – you buy the miner in addition to the heating you already use.

Air-cooled, immersion or hydro miner: which to choose?

The choice depends mainly on where you want the heat to go: an air-cooled machine heats the room it stands in, while immersion and hydro machines transfer the heat into water. You will find a more detailed technical comparison of cooling in the article Air or liquid cooling for ASICs.

Quiet air-cooled miner (0.8–1.7 kW)

The Canaan Avalon Mini 3, Canaan Avalon Q, Fluminer T3 and Fluminer L1 Pro plug into a normal socket and can stand in a room like an electric heater. According to Hashrate Index, the Canaan Avalon Mini 3 has a night mode of around 400 W and 33 dB, and in mining mode 800 W and 50–55 dB. The drawback is the low output: it will heat one room or provide supplementary heat, not a whole house.

Immersion miner (3.8–4.1 kW)

The Antminer S21 Imm and Antminer S21 XP Imm are submerged in a dielectric fluid that carries the heat to a heat exchanger. They suit a utility room or workshop where you already have a tank with fluid and a pump. Drawback: in addition to the machine itself you need a tank, fluid and a heat exchanger. The smallest of our immersion cooling kits is 12 kW, so it is more suited to a larger installation.

Hydro miner (5.6–5.9 kW)

The Antminer S19 XP+ Hyd, Antminer S21e Hyd, Antminer S21+ Hyd and Antminer S21e XP Hyd are cooled by water or antifreeze. The heat can be fed into central heating, a storage tank or a pool. The drawbacks are the three-phase supply, the water circuit and the need to dissipate heat even when the house does not need heating.

What you need at home: circuit breaker, power supply and heat distribution

A machine up to 1.7 kW can simply be plugged into a socket on a circuit with a 16 A circuit breaker; a 5.6–5.9 kW hydro machine needs a dedicated three-phase supply. Overview by type:

Electricity and circuit breaker

• Quiet air-cooled machines: at 230 V the Canaan Avalon Mini 3 draws about 3.5 A, the Fluminer L1 Pro about 6.1 A, the Fluminer T3 and Canaan Avalon Q about 7.2–7.3 A. Do not put a kettle or an oven on the same circuit and do not use extension cables.
• 3.4–4.1 kW machines: the iBeLink BM-S3+ would draw about 15 A at 230 V, the immersion Antminer S21 Imm and S21 XP Imm about 17 A. That calls for a dedicated circuit, not an ordinary socket. Check the supply voltage in the manual of the specific machine.
• Hydro machines: according to the manufacturer, the Antminer S21+ Hyd needs 380–415 V, three phases and max. 12 A. The supply with its own circuit breaker and inspection must be installed by an electrician. Also check whether your main circuit breaker and the capacity reserved with your distributor are sufficient.

Noise

Only machines of around 33–45 dB are suitable for a living room or bedroom, i.e. the Canaan Avalon Mini 3 in night mode, the Canaan Avalon Q or the Fluminer L1 Pro. Machines with 75 dB belong in a utility room, a garage or a soundproof box. We describe how to reduce noise in the article How to quieten an ASIC miner at home.

Heat distribution with a hydro miner

According to the manufacturer, the Antminer S21+ Hyd accepts coolant at 20–50 °C at a flow rate of 8–10 l/min. At 5,925 W the water in the machine heats up by roughly 8.5–10.5 °C. An outlet temperature of up to 60 °C is suitable for underfloor heating, low-temperature radiators, a storage tank or a pool.

• Heat exchanger: separate the miner's circuit from the heating with a plate heat exchanger. The machine has its own coolant requirements (water, demineralised water or antifreeze) and the circuit must be free of contaminants.
• Backup cooler: when the house does not need heat, a cooler outside or in the garage has to dissipate it. Our 12 kW water cooling (21,499 Kč, 38 dB according to the description) does this – it can cool one hydro machine even without heating. You will find more coolers in the radiators and dry coolers collection.
• Pool: heating 1 m³ of water by 1 °C takes 1.16 kWh. The Antminer S21+ Hyd delivers 142 kWh a day and could theoretically heat a 30 m³ pool by about 4 °C. We do not account for losses, which are large with an outdoor pool.
• Pump and controls: the flow rate, pump output and connection to your existing heating should be designed by a heating engineer for your house. We fit the cooling block to the machine as a service from 2,490 Kč.

Internet

Most machines connect via cable (Ethernet); the Antminer S21+ Hyd has an RJ45 port. Plan for a cable from the router to where the machine will stand.

When does heating with a miner make sense and when not?

A miner makes sense where you would otherwise heat directly with electricity – there it saves 31–51% of the heat cost. Typical situations:

• Makes sense: you heat with electric heaters or storage heaters, add heat to a study or attic, keep a workshop, garage or cottage frost-free, or heat a storage tank or pool with electricity.
• Makes sense with solar panels: in summer the same machine can mine on surplus power, see Mining on solar surplus.
• Does not make sense: you heat with a heat pump – it produces heat more cheaply (1.50–1.80 Kč/kWh). A miner would only replace it with a more expensive source.
• Does not make sense in summer: nobody needs the heat and at home you pay the full electricity price. Switch the machine off or move it to hosting.
• Does not make sense in a small flat with a machine above 1.7 kW: you will overheat the room, the noise is high and a socket is not enough.

If you do not use the heat, mining is cheaper in our ASIC miner hosting, where electricity costs from 1,14 Kč per kWh. The "Hosted" option of a machine has a discounted machine price; hosting is paid separately. New ASIC miners bought from us have a 7-year warranty in our hosting for as long as they run there.

What are the risks and drawbacks?

The main risk is that mining revenue, and therefore the saving, is not fixed. Before buying, take these drawbacks into account:

• Revenue changes: if network difficulty rises or the price falls, the same machine mines less. The heat stays the same, but the saving compared with an electric heater shrinks.
• Halving: at the next Bitcoin halving (estimated spring 2028) the block reward will be halved. At the same price, the net heat cost of the Antminer S21+ Hyd would rise from 2.50 to about 3.50 Kč/kWh.
• Noise: air-cooled machines above 1.7 kW produce around 75 dB and are not suitable for a flat without modifications.
• Maintenance: a miner runs non-stop and needs maintenance. Clean dust from air-cooled machines regularly; with a hydro circuit, check for leaks and the condition of the coolant. We do cleaning and fresh thermal paste in our service centre.
• Higher purchase price than an electric heater: you buy a machine for 27–101 thousand Kč, and with hydro also a circuit and a heat exchanger.
• Taxes: mined coins are income. We describe how they are taxed in the article Crypto mining in the Czech Republic: taxes and laws.

New machines from us come with a 24-month warranty. If a machine needs repair, our ASIC miner service in Prague takes care of it.

How to proceed step by step?

1. Find out what you currently heat with and how much you pay for 1 kWh of electricity including distribution.
2. Decide where you want the heat: one room (air-cooled machine), or water in the heating system or pool (hydro).
3. Choose a machine from the table above by output and noise. Check the current revenue on the ASIC miner profitability page.
4. For machines above 3 kW, have an electrician check the supply and circuit breaker; for hydro, have a heating engineer design the circuit and heat exchanger.
5. Work out where the heat will go in summer: a backup cooler, solar panels or hosting.

This is not investment advice; mining revenue changes with the exchange rate and network difficulty.

What next

• Miners for home mining – quiet machines for flats and houses with current revenue.
• Water circuits for hydro miners and mining sets – a hydro machine with a cooler in one package.
• ASIC miner profitability – live revenue and profit of all machines in our range, recalculated every hour.
• Mining from solar panels and heating with a miner – a calculator for your own electricity price and surplus.
• How to quieten an ASIC miner at home – soundproof box and quiet miners.

Sources

• Bitmain: Antminer S21+ Hyd – manual (power supply 380–415 V, coolant 20–50 °C, flow rate 8–10 l/min)
• Bitmain: Antminer S21 Hyd – specifications
• Hashrate Index: Avalon Mini 3 – modes, power draw, noise and air temperature
• Bosch Home Comfort: COP and SCOP of heat pumps (in Czech)
• Skrblík.cz: Gas price 2026 (January 2026, in Czech)