Ruben BO Black 21kw Contemporary Stove with 4 Port Back Boiler. 

“Eco Design 2022 Compliant” 

A stylish wood burning and multi-fuel stove, that incorporates a large ceramic glass window, silver door handles / controls and an integrated back boiler for hot water and central heating. Hand built in Europe to a high standard and finished in charcoal dark grey (almost black), with a choice of Red or Ivory coloured sided, the Ruben BO is a substantially constructed stove, and is finished to the very highest of standards.

The integrated back boiler offers 7kw to water heating, leaving 8kw to room heating. There are 4 water connections on the rear of the stove, 2 x flow and 2 x return, all connected to one chamber – size = male 1″ BSP. The 18.64 litre back boiler on this stove is extremely efficient and will heat up to 10/12 radiators and domestic hot water.

The back boiler is designed to be used on an un-vented hot water system up to a maximum operation pressure of 2 bar, (rated up to 4 bar) it can also be used on a non pressurised “vented” hot water system.

In addition the back boiler incorporates an internal cooling coil, which runs through the main back boiler. The purpose of the coil is to cool the water within the back boiler before it reaches boiler point. This is achieved with an additional control valve called a TAS valve. The cooling coil is designed to be fed by a mains cold water feed, and the cooling water is then discharged to waste water drain. The mains cold water feed is controlled by a mechanical TAS valve which monitors the temperature of the water within the back boiler and opens when the water reaches 96 degrees. This releases a burst of mains-cold-water, which is released through the cooling coil, thus reducing the temperature of the water within the back boiler. The cooling water is kept separate from the water within the back boiler and therefore no contamination can take place. The mains cold water is then discharged to an outside drain.

When using the Ruben BO 4 port stove with an un-vented hot water system,  we recommend that you install a 25 litre expansion vessel and at least two 3 bar pressure release valves. We also recommend that you use our approved “thermostatic pump station” in order to increase the efficiency of the stove. Please note that the TAS valve is not included with the stove.

Primary and secondary air controls allow complete and effective control over both the burn rate and temperature output, in order to maximise the efficiency of the stove. The iStove Lux also has an advanced pre-heat air wash system that ensures the large glass window stays clean to give a clear view of the flames. Further features include a large removable ash pan for easy cleaning and maintenance and a multi fuel fire grate.

The stylish design and clean lines compliment the contemporary look of this compact, yet high output stove.

The Ruben BO with 4 port back boiler carries a 2 year warranty and the following quality standards:

In accordance with all the stoves that we offer, the Ruben carries a 2 year warranty and is CE Marked to EN13240 (latest standard) and manufactured to ISO 9001 Quality Standard… please do not confuse this stove with other cheaper alternatives, it’s build quality and finish compares to other stoves that are considerably more expensive. We are often asked how we can offer our stoves at such competitive prices?.. We buy direct from the manufacturers, so there is no distributor middle man, we buy in bulk, which reduces the cost price, we handle our logistics to further reduce the “landed” cost of each stove, and we are an e-commerce company with low overheads..the result..You save money on your stove. Our low prices do not reflect low quality.. Guaranteed..or your money back!

Price Includes FREE delivery to most of the mainland UK ( Next Day delivery service from date of dispatch )


Space Heat Output: 7kw – Water Heating Output 14kw,

Back boiler rated to a max working pressure of 2 bar

Dimensions: Width 692mm / Depth 455 / Height 853mm

Firebox: Depth 290mm, width 566mm, height 320mm

Weight: 165kg

Colour: Black, Polished Silver Door Handle and Controls 

Flue Diameter: 6 inches (150mm) – (Requires a Euro Adapter £29.99

Features: Eco Design 2022 Compliant, Ceramic Glass Window. Advanced Airwash, Primary and Secondary Air Control, Top or Rear Flue Exit, Large Removable Ash Pan

Back Boiler incorporates 2 x Flow and 2 x Return Water Connections + 1 x flow and 1 x return for the internal cooling coil. The Water connections are 1 inch BSP for the flow and return and half inch BSP for the cooling coil. NB. a TAS Valve is required for the cooling coil, it is NOT included

Flue Outlet: Top Only – Requires A Euro Adapter

Efficiency: 79.5%

Fuel: Wood Burning & Multi Fuel – Peat, Smokeless Fuel.. etc

Warranty: 2 years

Suitable for a non construction 12mm hearth