Warmth that pays off.
The heater Ofen 2 Pro warms your home and generates cashback.
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What customers say
5,000+ satisfied customers and trusted by thousands of homes across Europe.
The app (iOS) is well made and feels intuitive, the heater itself is very quiet even when running at its maximum power. I have using it for 5 days now and so far I'm very happy. I almost never write reviews but this company deserves to get recognition
Daniel Garcia
January 14, 2026
Excellent service as always! Thank you again 😊
JonnyW
February 5, 2026
Had an error at first but to be fair they did everything to rectify it and put it right and more
andrew ferguson
April 2, 2026
Perfect ! I receive everything and travel was long. Thx to all team !
Vivien Gaillard
January 8, 2026
Top Support 👍
Alex Tornyossy
March 23, 2026
all good, works well, good support.
Fredrik Åhslund
December 22, 2025
Ofen 2 is good product and there is a good service support. The product is well designed and well manufactured. I got a minor bug issue at the beginning with the thermostat. Support solved it very quickly with an update.
Jidé Jidé
December 4, 2025
Awesome Team. Had a great conversation with a customer service agent, helped me understand the inner workings of mining!
Remington Splettstoesser
September 24, 2025
Efficient by design
Quiet warmth
Whisper-quiet (~35 dB) so it blends into your living room.
Cashback
77 high performance processors turn electricity into warmth and Bitcoin.
Desired temperature
Set your desired temperature and the thermostat maintains it day & night.
Built to last
Premium aluminium for long life and low maintenance.
Touch-safe design
Enclosed heating core and rounded edges, CE certified.
Quiet warmth
Whisper-quiet (~35 dB) so it blends into your living room.
Cashback
77 high performance processors turn electricity into warmth and Bitcoin.
Desired temperature
Set your desired temperature and the thermostat maintains it day & night.
Built to last
Premium aluminium for long life and low maintenance.
Touch-safe design
Enclosed heating core and rounded edges, CE certified.
See it in action
Details in a nutshell
Ofen 2 Pro
Ofen 2
Which heating saves you the most in {country}?
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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.
Bitcoin Central Heating.
Heat your home, your water & earn Bitcoin all year long. Even more profitable with solar.
Questions & Answers
Shipping
When will my products be delivered?
We typically ship all products within 2-3 business days. Following that, your order will reach you within a few business days, depending on the delivery location. Any pre-orders or delays will be indicated in the description or in a separate message.
In which countries does 21energy ship to?
Currently, we ship to the EU, Switzerland, Norway and Great Britain. If you want to find out if we deliver to your address, you can easily test this in the checkout process by entering your address there.
What are the shipping costs for me?
The shipping costs vary depending on the delivery location. To calculate your personal shipping costs, you can go through the checkout process. After entering the delivery address, the costs will be displayed to you. All orders over €200 qualify for free shipping!
Are there any additional costs for customs or taxes?
For all customers within the EU, there are no additional costs due to taxes and customs. All customers outside the EU pay only the net price in the store when ordering. Therefore, taxes and duties will be incurred upon import and are to be paid there.
Can I cancel my order?
Yes, every customer has a 30-day right of withdrawal. Within this period, you can cancel your order without providing any reasons. The paid amount will be refunded to you via the originally selected payment method.
Income
How do the 21energy heaters and computers (mining devices) make money?
21energy heaters and computers (mining devices) generate revenue through the process of Bitcoin mining, wherein specialized hardware solves cryptographic puzzles to validate and secure transactions on the blockchain network. As a reward for their computational work, miners receive newly minted bitcoins and transaction fees.
How much can I earn from heating with the heaters or other mining devices?
Your mining earnings depend on various factors such as the price of Bitcoin, market rates for computations, global hashing power, duration of operation, and hardware model. For your individual situation, we have developed a profitability calculator. The significant distinction from any other electric heater is that cash flow is generated while heating.
Performance
Do the different products require more electricity than traditional heaters?
No, these products do not require more electricity than traditional heaters. They efficiently convert 100% of the electrical energy into heat, simultaneously utilizing it to mine Bitcoin, effectively leveraging energy in a dual capacity.
Does my electricity bill change with 21energy products?
If the same heating method (electric heating) with the same heat demand is applied as before, the electricity bill usually does not change, as the entire electrical energy continues to be converted into heat.
Can the heating power be adjusted on the individual devices?
All our devices offer several heat levels you can choose from.
How much heating area do 21energy products cover?
The heating area of each heater is specified in the product descriptions, which may vary significantly depending on their characteristics. For all individual hardware devices, the heating area can be determined using various calculators available online, based on the specified power output.
Are the products allowed to be overclocked to achieve maximum yield?
Our heaters are only allowed to be operated at the maximum power specified in the description and/or user manual. Overclocking poses a high risk and will void the warranty immediately. Similarly, each individual Bitcoin mining device should only be operated at its maximum standard power.
Safety & Warranty
Are the devices designed for maximum safety and CE compliant?
All products sold have been tested according to the highest and latest safety standards and are CE compliant.
Are safety mechanisms installed in the various devices to prevent overheating?
All our heaters are equipped with a special operating system designed to prevent overheating by shutting down the device beforehand.
Can 21energy products be operated around children?
Yes, our products are designed for use in residential spaces like traditional homes. They are conventional electrical appliances. Therefore, the usual precautions for children apply.
Is there a warranty on 21energy heaters and other products?
Provided that the safety precautions outlined in the user manual are followed, our heaters come with a 12-month warranty. This also applies to all of our newly and originally packaged Bitcoin miners.
Business
I would like to partner with you. What options are available? Is it possible to collaborate with 21energy as a distribution partner?
Please feel free to submit an inquiry through our <a href="https://21energy.com/pages/business-solutions#contact" title="https://21energy.com/pages/business-solutions#contact">contact form</a> on the website. Please provide all necessary information so that we can process your request as efficiently as possible.
Are there special pricing tiers for larger quantities?
Yes, we have specific pricing tiers for certain products starting from a certain quantity. Please feel free to send us an inquiry through our <a href="https://21energy.com/pages/business-solutions#contact" title="https://21energy.com/pages/business-solutions#contact">contact form</a> for more information.
Is it possible to invest in 21energy?
Please feel free to email us at <a href="mailto:office@21energy.com" target="_blank">office@21energy.com</a> and we will get back to you.
Are there any open positions at 21energy currently?
Please have a look at our <a href="https://21energy.com/pages/careers#jobs" title="https://21energy.com/pages/careers#jobs">open positions</a>.
