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Extraflame THEOREM PLUS AD Pellet stove 25.8 kW black
With a wide range of room heating capacity from 146-740 m³, you can heat small to very large areas as needed. The rated thermal output of 12 kW allows precise adjustment to your heat demand - efficient at partial load and powerful when it matters.
Price incl. VATNew productsConsumer Rights Act 2015
Estimated delivery
Home delivery · 7 to 9 business days · free from £350 (otherwise £35.99)
Sold and shipped by Perth Stove Centre Ltd
Extraflame TEOREMA PLUS AD with WiFi Control and Ducting
The Extraflame TEOREMA PLUS AD is the stylish choice for anyone who wants to heat their home comfortably, modernly, and reliably. With its integrated WiFi control and the option for ducting to multiple rooms, it is aimed at discerning users who value design, ease of use, and strong brand quality.
As a novelty in the Evolution line, you benefit from a current model generation that relies on advanced technologies - for more comfort in everyday life and a future-proof investment. Its classification in the Prestige line highlights the high-quality design and meticulous craftsmanship.
Features & Benefits
- WiFi control with Total Control 3.0
Control the pellet stove conveniently via smartphone app - for comfortable operation from anywhere and programmable heating times according to your daily routine. - Double ducting up to 8 meters
With two independent motors and thermostat-controlled air distribution, you can heat multiple rooms precisely - ideal for open living concepts or multi-story areas. - Integrated glass cleaning
The automatic glass cleaning system prevents dirt buildup on the viewing window through a specific preheated airflow - for a consistently clear view of the fire. - Pull-out cast iron burn pot
The cast iron burn pot can be completely removed for quick, thorough cleaning - less maintenance, longer lifespan. - Large 27 kg pellet container
The generous fuel container allows up to 34 hours of continuous operation per filling - less frequent refilling, more heating comfort. - Automatic primary and secondary air control
The electronic air regulation automatically optimizes combustion for maximum efficiency and even heat distribution. - Cast iron fire door and firebox
High-quality cast iron components do not deform over time and ensure constant sealing for optimal combustion quality. - Ergonomic handle
The specially shaped door handle fits comfortably in the hand and allows safe opening even at operating temperature. - Design in black (Nero)
The black surface with textured paint matches various interior styles and sets striking accents in the living area.
Application & Field of Use
With a broad range of room heating capacity from 146-740 m³, you can heat small to very large areas as needed. The nominal heat output of 12 kW allows precise adjustment to your heating requirements - efficient in part-load operation and powerful when it matters.
The Extraflame TEOREMA PLUS AD, with its dimensions of 1080 × 525 × 652 mm, stands on a compact footprint and requires minimum distances of 100 mm from combustible materials at the back and sides, and 800 mm in the radiation area in front. The weight of 172 kg requires a stable setup and should fundamentally be handled by two people.
The flue pipe connection with a diameter of 80 mm can be made either at the back or on top, and the external combustion air is supplied via a 50 mm connection at the back. As a pellet stove approved for pellets, it offers clean operation and convenient fuel logistics with a consumption of 0.9-2.7 kg/h depending on the power level.
The ducting function with two motors allows heat distribution to up to two additional rooms via pipes up to 8 meters long. The thermostat-controlled Air Zone Control ensures demand-based temperature regulation in the individual areas.
The appropriate accessories, e.g., stove pipes for your pellet stove for connection to the chimney, are of course also available in our shop.
Approvals & Standards
- Ecodesign Stage 2 - Meets the requirements of Stage 2 of the Federal Immission Control Ordinance for low emission values
- CE Marking - Confirms conformity with European safety and health standards
- DIN 18896 - German standard for pellet stoves and their requirements for safety and performance
- EN 13384 - European standard for the calculation and design of flue gas systems
- EN 16510 - European standard for room air dependent appliances for solid fuels
FAQ: Frequently Asked Questions about the Extraflame TEOREMA PLUS AD Pellet Stove
For which room size is the Extraflame TEOREMA PLUS AD suitable?With a nominal heat output of 12 kW, it heats rooms from 146 to 740 m³, which corresponds to approximately 58 to 296 m² with a ceiling height of 2.5 m. Thanks to the ducting function, you can additionally direct the heat to up to two other rooms - ideal for open living spaces or multi-story houses.
How does the WiFi control work on the TEOREMA PLUS AD?The device features integrated WiFi and the Total Control 3.0 app. This allows you to conveniently control temperature, heating times, and operating modes from your smartphone - even on the go. You can create weekly schedules and have the oven start automatically before your arrival.
Which pellets can I use in the TEOREMA PLUS AD?It is only approved for wood pellets. Use high-quality pellets according to DIN EN 14961-2 or ENplus-A1 standard. The 27 kg pellet container holds enough fuel for up to 34 hours of continuous operation at medium power. More on this in our magazine: Pellet storage at home - tips & avoid common mistakes
How often does the pellet stove need maintenance?You should clean the pull-out combustion bowl weekly to every two weeks depending on usage. Annual maintenance by a professional is recommended for wear parts and seals. The glass cleaning system significantly reduces the cleaning effort for the viewing glass. More on this in our magazine: Maintenance Costs of Pellet Stoves - Honestly Calculated
Can I set up the TEOREMA PLUS AD myself?Due to the weight of 172 kg, setting it up requires at least two people. However, connection to the chimney and the initial start-up must be approved by the chimney sweep. Check the chimney cross-section and draft conditions in advance for the 12 kW output.
How loud is the operation of the pellet stove?The device operates with two ducting motors and a flue gas fan. During normal operation, the noises are comparable to a quiet refrigerator. The volume varies depending on the power level - at low settings it is barely noticeable, at full load more noticeable but not disturbing.
Extraflame - Pellet Stove Specialist from Northern Italy Extraflame is part of the La Nordica-Extraflame Group and has established itself as one of the leading manufacturers in the field of pellet stoves. The range extends from room air-independent pellet stoves to water-carrying models and even pellet boilers - produced in five manufacturing facilities entirely in Italy. Typical are the coverings made of handcrafted majolica ceramics or natural stone as well as high efficiency at low emissions. |
- Nominal heat output
- 12 kW
- Efficiency
- 93 %
- Maximum room heating capacity
- 740 m³
- CO emission
- 125 mg/cm³
- Fine dust emission
- 10 mg/m³
- Exhaust gas mass flow
- 6.3 g/s
- Exhaust gas temperature at the connector
- 191 °C
- Minimum distance to combustible materials
- rear 100 mm - side 100 mm - front 800 mm
- Dimensions (H x W x D)
- 1080 x 525 x 652 mm
- Weight
- 172 kg
- Ø Flue pipe connection
- 80 mm
- Direction of flue pipe connection
- rear
- Ø External air supply
- 50 mm
- Direction of air supply connection
- rear
- Approved fuel
- Pellets
- Fuel consumption
- 2.1 kg/h
- Required fan pressure at nominal heat output
- 5 Pa
- Pellet container capacity
- 27 kg
- Voltage
- 230 V
- Multiple occupancy / type
- No / Type 2
- Integrated glass cleaning
- Separate primary and secondary air control
- Standards, approvals, and directives met
- Ecodesign Stage 2, CE, DIN 18896, EN 13384, EN 16510, EcoDesign Directive, Flamme Verte, V 18160-1
| Nominal heat output | 12 kW |
|---|---|
| Efficiency | 93 % |
| Maximum Room Heating Capacity | 740 m³ |
| CO Emission | 125 mg/cm³ |
| Fine Dust Emission | 10 mg/m³ |
| Exhaust Mass Flow | 6.3 g/s |
| Exhaust Temperature at the Outlet | 191 °C |
| Minimum Distance to Combustible Materials | rear 100 mm - sides 100 mm - front 800 mm |
| Dimensions (H x W x D) | 1080 x 525 x 652 mm |
| Weight | 172 kg |
| Ø Flue Pipe Connection | 80 mm |
| Direction of Flue Pipe Connection | rear |
| Ø External Air Supply | 50 mm |
| Direction of Air Supply Connection | rear |
| Approved Fuel | Pellets |
| Fuel Consumption | 2.1 kg/h |
| Required fan pressure at nominal heat output | 5 Pa |
| Pellet container capacity | 27 kg |
| Voltage | 230 V |
| Multiple occupancy / Design type | No / Design type 2 |
| Standards, approvals and directives met | Ecodesign emission limits Level 2, CE, DIN 18896, EN 13384, EN 16510, EcoDesign Directive, Flamme Verte, V 18160-1 |
| Brand | Extraflame |
| Item number | extraflame-teorema-plus |
| EAN | 9201810311718 |
Additional information
| Rated thermal output | 12 kW |
|---|---|
| Efficiency | 93 % |
| Max. room heating capacity | 740 m³ |
| CO emissions | 125 mg/cm³ |
| Fine dust emissions | 10 mg/m³ |
| Flue gas mass flow | 6,3 g/s |
| Flue gas temperature at spigot | 191 °C |
| Minimum clearance from combustible materials | hinten 100 mm - seitlich 100 mm - vorne 800 mm |
| Dimensions (H x W x D) | 1080 x 525 x 652 mm |
| Weight | 172 kg |
| Flue connection Ø | 80 mm |
| Flue connection direction | hinten |
| Ø Externe Zuluft | 50 mm |
| Combustion air connection direction | hinten |
| Approved fuel | Pellets |
| Fuel consumption | 2.1 kg/h |
| Required feed pressure at nominal heat output | 5 Pa |
| Capacity of pellet container | 27 kg |
| Spannung | 230 V |
| Mehrfachbelegung / Bauart | Nein/Bauart 2 |
| Fulfilled standards, approvals, and guidelines | Ecodesign emission limits Stufe 2, CE, DIN 18896, EN 13384, EN 16510, EcoDesign-Richtlinie, Flamme Verte, V 18160-1 |
| Marke | Extraflame |
| Item number | extraflame-teorema-plus |
| EAN | 9201810311718 |
Delivery and shipping
Delivery and tracking
Orders leave our Perth warehouse for the UK address on your order. Heavy appliances and fuel go on a pallet and stop at kerbside (or the closest firm ground the lorry can reach).
- Preparation: usually within 24 to 48 working hours after payment.
- Transit: about 7 to 9 working days after the carrier collects, depending on region and stock. Weekends and bank holidays do not count.
- Shipping costs: appliances £35.99 incl. VAT, or free from £350 of appliances. Firewood and pellets use pallet rates and are never free. Delivery policy.
- Tracking: emailed when the carrier takes the goods.
Returns and refunds
- Cooling-off: 14 days under UK distance-selling rules. We also take unused, resaleable returns up to 45 days. Details on the Returns page.
- Refund: started after we receive and check the return.
Frequently asked questions about this product
Power cuts, noise, pellets, installation, and delivery—what buyers usually ask before ordering a pellet stove.
Do you install this stove?
We do not install stoves or flue systems ourselves. Perth Stove Centre Ltd supplies the appliance and arranges carriage to your address. A qualified installer registered with HETAS (or an equivalent competent-person scheme) must fit the stove, connect the flue, and certify the work against Building Regulations Part J where that applies in your area.
We can confirm external dimensions, shipping weight, and the nominal heat output from the manufacturer datasheet so your fitter can check room size and liner diameter before you commit. Smoke Control Area authorisation, planning constraints, and grants that need an installer's invoice sit outside this online sale. Most buyers order the stove here and book the fitter once a delivery week is known.
How does stove delivery work at home?
Orders on this site leave our UK warehouse for the delivery address you enter at checkout. Deliveries outside the United Kingdom need an email agreement before payment, because carrier rules differ. Palletised stoves and inserts are handed over at kerbside or the nearest firm ground the HGV can reach. The driver does not carry units upstairs, through narrow hallways, or across soft ground without prior arrangement.
Before you pay, compare the pallet weight and crate size on this page with your doorway, path, and any steps. If access is tight, tell us when you order. When the goods arrive, inspect the packaging while the driver is still there. If the crate is crushed, torn, or clearly mishandled, write dated reservations on the delivery note (not a vague "subject to unpacking" line), take photographs, and email [email protected] within 48 hours with your order number so we can open a carrier claim.
Who sells and ships this product?
The seller is Perth Stove Centre Ltd, a company registered in Perth, Perth and Kinross, Scotland. We trade as a specialist hearth and solid-fuel retailer: we hold stock, prepare orders, and ship the reference shown on this page. We are not a marketplace listing other people's inventory. Registered office, company number, and contractual terms are in our legal notice.
You buy on thestovecentre.com, pay by card before dispatch, and we deliver to the mainland UK address on your order confirmation. No walk-in counter, no depot collection, and no cash or card payment to the driver. Sizing, lead times, or access questions before checkout: [email protected].
Is the product new?
What you see here is normally current manufacturer stock, supplied new and in the maker's factory packaging when the factory still provides one. Ex-display, end-of-line, or refurbished lines are uncommon on this catalogue; when they do appear, the product page states that in plain words in the description.
Your statutory rights under the Consumer Rights Act 2015 apply if the goods arrive faulty or not as described. Keep the email confirmation and invoice. Where the manufacturer publishes a warranty for this reference, that warranty sits alongside for eligible parts under the maker's own registration rules and time limits.
How do you explain the displayed price?
The catalogue mixes stoves, inserts, flue parts, and accessories from manufacturer end-of-line batches and scheduled stock rotations. The goods stay new; when the factory ships retail packaging, that is what arrives on the pallet.
Carriage for qualifying appliances is £35.99 including VAT, or free when the appliance subtotal in your basket reaches £350. Kiln-dried firewood, pellets, and other fuel lines never count toward that threshold. Checkout shows the exact shipping line before you pay. No shop pickup, and nothing is settled with the carrier at the door.
Does a pellet stove need electricity, and what happens in a power cut?
Yes. Ignition, the auger that feeds pellets, and the combustion or convection fans all need mains power. When the supply drops, the stove shuts down; it will not keep heating like a simple wood stove.
If winter blackouts are common where you live, plan a suitable UPS or generator sized for the stove's stated draw, or keep a wood appliance as backup. We sell the stove; we do not supply backup power kits unless listed as a separate accessory on the site.
How noisy is a pellet stove day to day?
You will hear the auger and at least one fan. Convection (natural draft) models stay quieter than forced-air designs, but none are silent. Noise rises when the stove is pushing hard to reach set temperature and drops once it settles into a lower burn.
If quiet evenings matter, read the datasheet dB figure where the maker publishes one, and prefer convection over ducted forced air. Living with a sample in a showroom is ideal; online, treat "whisper quiet" marketing with caution.
What pellets should I use, and how often do I refill?
Stick to dry ENplus A1 (or the grade named in the manual). Damp pellets swell, jam the auger, and can wreck the feed motor. Store bags indoors off concrete, sealed, away from rain and garage damp.
Hopper size on the page tells you how long a fill lasts at a given output. A typical 15 kg bag is a full hopper on many room heaters; at high burn that may be under a day, at gentle heat a couple of days. Ash still needs emptying on a regular schedule even when the glass looks clean.
5 reviews for Extraflame THEOREM PLUS AD Pellet stove 25.8 kW black
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Secure payment
Encrypted payment (SSL). Your card details are not stored.
Home delivery
Free appliance delivery from £350 in the cart (firewood and pellets never count). Delivery policy.
Returns
14-day cooling-off under UK distance-selling rules, plus a commercial return window up to 45 days when goods stay unused and resaleable.
Customer service
Reply by email, Monday to Saturday.
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Jack F. –
I undersized the room: too strong for a small space. Unit fine, my choice was wrong.
Grace L. –
Night programme is quiet. On high, the fan is only noticeable during the day.
Matthew V. –
Ash stays low if I keep a medium flame. Controls clear after one evening.
Christopher D. –
Burns cleanly on ENplus A1 bags. Hopper fill lasts through a workday on eco.
Matthew V. –
Missed the side clearance on the product page. Had to move a cupboard. Our mistake.