Ofen 2

Bestseller

€1.741,67

Price excl. VAT
Free shipping
Delivery: ...
Color
1,000 W
Power
up to 50 m²
Area heated
up to 40 TH/s
Mining power
€ 562 per winter *
Bitcoin earnings
90 × 32 × 14 cm
Size
35 dB
Noise level
* Based on 4-year BTC average as of 01.2026
Free shipping Free shipping
Delivery:
30-day-return 30-day-return
5,000+ Satisfied customers 5,000+ Satisfied customers
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Bought together

Premium Stand (Ofen 2 & Ofen 2 Pro)
Premium Stand (Ofen 2 & Ofen 2 Pro)

Premium Stand (Ofen 2 & Ofen 2 Pro)
€40,83
Wall Mount (Ofen 2 & Ofen 2 Pro)
Wall Mount (Ofen 2 & Ofen 2 Pro)

Wall Mount (Ofen 2 & Ofen 2 Pro)
€40,83

Ofen 2 always includes a basic stand.

Product information

The 21energy Ofen 2 is perfect for you, if you want to heat your home and earn Bitcoin at the same time. Imagine having a heater that not only keeps your home warm, but also provides you with additional income. The Ofen 2 offers a heat output of up to 1,000 watts and can heat rooms up to 50 m². It runs whisper-quiet — under 35 dB on the lowest setting, 40 dB on the medium setting and 45 dB on the highest setting.

Power & ease of use

The Ofen 2 from 21energy offers a heat output of up to 1,000 watts and enables uncomplicated plug & play commissioning for particularly easy handling. This combination of performance and user-friendliness enables effortless use and optimum heat supply. Simple connection via WLAN and initial configuration with the 21energy-app takes just a few minutes. With the supplied operating instructions and a video tutorial, installation is very easy and child's play even for non-technical users.

Heating technology & noise level

Thanks to the innovative combination of convection and radiation, the heater provides even heat distribution. Even at it's high output, the Ofen 2 remains extremely quiet and ensures quiet operation with less than 45 dB at 1,000 watts, creating a pleasant room climate.

Design & mining power

The Ofen 2 made of premium materials & powder‑coated steel not only gives the heater an aesthetic appearance, but also ensures robustness and durability. With a mining power of up to 40 TH/s and an efficiency of up to 20 J/TH, the Ofen 2 offers impressive performance.

Protection & durability

The air and dust filters of the Ofen 2 provide effective protection against dirt deposits in the appliance, protecting the internal hardware and extending the life of the heater. The galvanized sheet metal provides durability and corrosion resistance, ensuring reliable use of the heater in a wide range of conditions.

Mining pool

The built-in Bitcoin miner is compatible with various mining pools and can also be used for solo mining.

Operating system

The Ofen 2 comes with the Braiins OS+ operating system, which offers automatic optimization and increases efficiency by up to 20%. This auto-tuning function enables improved cash flow and a higher hashrate of up to 20% with the same power consumption.

Savings potential

The savings potential of the Ofen 2 depends on individual energy costs and Bitcoin mining profitability. Calculate your individual heating cost savings now with our profitability calculator.

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Ofen 2

Bestseller
Ofen 2 – Premium Stand - 21energy
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5 stars 1,000+ reviews
Trustpilot 4.9
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5 stars 1,000+ reviews
Trustpilot 4.9
Google 4.9
5,000+ happy customers in 35 countries worldwide
4.9 out of 5 star rating verified on Trustpilot
Fast shipping from Austria with no customs in EU
Fast & expert multilingual support

What customers say

5,000+ satisfied customers and trusted by thousands of homes across Europe.

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In the box

Ofen 2

1.000 W

Thermostat

Connect via Bluetooth

Power cord

1 m

Manual

Quickstart guide
Calculate your earnings

Calculate your earnings

Electricity
&
Heat & Bitcoin
Earnings

You earn

€ 0,13 / kWh cashback
€ 562 / winter
How it's calculated = € 0,13 × 1,0 kW/h × 24 hours × 180 days
(Based on BTC average as of 01.2026)
Buy Ofen 2 now Calculate personal earnings
Trustpilot

Known from

Ofen 2 explained

Ofen 2 explained

Based on
Austria flag Austria Dropdown

Ofen 2 explained

Based on
Austria flag Austria Dropdown
Buy Ofen 2 Pro now

Pay securely via

Visa
Mastercard
Klarna
Apple Pay
Google Pay
Bitcoin

Efficient by design

Hashboard Circuit Board

Quiet warmth

Whisper-quiet (~35 dB) so it blends into your living room.

Pays you back

Cashback

77 high performance processors turn electricity into warmth and Bitcoin.

Thermostat

Desired temperature

Set your desired temperature and the thermostat maintains it day & night.

Premium Materials

Built to last

Premium aluminium for long life and low maintenance.

Touch safe

Touch-safe design

Enclosed heating core and rounded edges, CE certified.

Hashboard Circuit Board

Quiet warmth

Whisper-quiet (~35 dB) so it blends into your living room.

Pays you back

Cashback

77 high performance processors turn electricity into warmth and Bitcoin.

Thermostat

Desired temperature

Set your desired temperature and the thermostat maintains it day & night.

Premium Materials

Built to last

Premium aluminium for long life and low maintenance.

Touch safe

Touch-safe design

Enclosed heating core and rounded edges, CE certified.

Buy Ofen 2 Pro now
Austria Flag

Made in Austria

See it in action

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Based on
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Ofen 2
Ofen 2 Dropdown
Oil heating
Oil heating
Gas heating
Gas heating
Heat pump
Heat pump
Purchase price
€1.741,67
Low upfront investment
Purchase price
€ 17,000
~8 x higher upfront
Purchase price
€ 15,000
~7x higher upfront
Purchase price
€ 15,000
~7x higher upfront
Seasonal costs
€ 4,290
Seasonal costs
€ 2,830
Seasonal costs
€ 2,060
Seasonal costs
€ 1,070
Seasonal savings
€ 3,300
Ofen 2 pays you back
Seasonal savings
€ 0
No savings
Seasonal savings
€ 0
No savings
Seasonal savings
€ 0
No savings
Net seasonal costs
€ 990
Net seasonal costs
€ 2,830
Net seasonal costs
€ 2,060
Net seasonal costs
€ 1,070
CO₂ emissions
Low
Environmentally friendly
CO₂ emissions
High
Unsustainable
CO₂ emissions
Moderate
Unsustainable
CO₂ emissions
Low
Environmentally friendly
Buy Ofen 2 Pro now

Pay securely via

Visa
Mastercard
Klarna
Apple Pay
Google Pay
Bitcoin

Questions about Ofen 2

Can I operate the Ofen 2 with a LAN cable?

Yes, there is a USB port on the back of the Ofen 2, through which you can connect a LAN cable using a suitable adapter.

How can I control the Ofen 2?

The Ofen 2 can be controlled via the 21energy App. You can turn it on and off, adjust the heating levels, connect it to a thermostat, create schedules, and integrate it into your Home Assistant setup.

Do I need a Bitcoin wallet?

A Bitcoin wallet is required if you want to store the earnings from your mining pool yourself. Alternatively, you can send the earnings directly to an exchange and have them paid out in euros.

How do I receive the mined Bitcoins?

The Bitcoins mined by the Ofen 2 are first credited to your mining pool account. From there, you can transfer them to your Bitcoin wallet or directly to an exchange. More details can be found in theuser manual, section 5.4.

Do I need a good internet connection?

The Ofen 2 requires very little bandwidth (<1 Mbit/s). The most important factor is that the connection is stable and reliable.

Can the Ofen 2 be mounted vertically?

This is not recommended by default and should only be done if the Ofen 2 is placed and secured carefully and safely. The wall mount is designed only for horizontal installation.

Can I control my 21energy device with my smart home system?

Yes. The Ofen 2, Ofen 2 Pro and Port are all controlled through the 21energy App. For Home Assistant there is an official integration. Every other system can control the device through its open API. You will find the full interface specification in the app under "Automations".

Still looking for an answer?

Contact support

Good for the environment

The operation of the Ofen 2 can save up to 3 tons of CO₂ per year compared to conventional heaters.

Dive into the specifics

Discover our innovative Bitcoin heaters and find out how it helps you to heat more efficiently and save money.

Niko Jilch

The ingenious idea behind the Bitcoin start-up from Tyrol
Maximilian Obwexer

This saves much more oil than a Tesla
Maximilian Obwexer Swiss Bitcoin Conference 2024

Bitcoin Mining (Talk at Swiss Bitcoin Conference 2024)
Lukas Waldner Blocktrainer Event

Energy Transition through Bitcoin Mining
21energy App Mockup

Set up in 3 minutes using the app.

Download the app on the App Store Download the app on Google Play