Product Overview & Application Area
The ROJEK PK BIO 25 is a manually fed wood gasification boiler with a nominal output of 25 kW for dry split logs. The pyrolysis principle combines a large fuel chamber with electronically assisted combustion control and is suitable for appropriately designed hot water central heating systems in residential buildings, workshops, and similar applications.
The 130-liter filling chamber accommodates split logs up to 530 mm in length and 250 mm in diameter. Top loading allows the available combustion chamber volume to be utilized effectively. With suitable fuel quality and operating methods, long burn times are possible.
Technology & Equipment
The PK BIO 25 operates with electronic control and an induced draft fan. Combustion management is thus adapted to the boiler's operating conditions. The wood gasification boiler achieves an efficiency of 90.0% when burning split logs, meets boiler class 5, and complies with Ecodesign requirements.
Cleaning of the fire-tube heat exchanger is supported by an externally mounted operating lever. The operating mechanism can be structurally relocated to the left side of the boiler. A cooling loop enables the integration of the required thermal safety device against overheating.
The door hinge is on the right as standard and can be ordered as a factory option on the left. The flue gas outlet is vertical in the PK-BIO series. A horizontal flue gas outlet variant is not available as a regular factory option for the PK BIO 25.
Everyday Benefits
Top loading makes it easier to insert longer logs and allows good use of the large fuel space. The induced draft fan supports combustion and improves flue gas flow during operation. The electronic control handles essential boiler control functions.
An externally mounted operating lever is available for regular cleaning. The combustion chamber, heat exchanger, and flue gas paths remain easily accessible within the scope of scheduled maintenance. The door, which can be hinged on the right or left, also allows adaptation to different space conditions in the boiler room.
System integration & compatibility
The required chimney draft is between 12 and 17 Pa. The flue gas outlet has a diameter of 159 mm. For proper boiler operation, a minimum temperature of 63 °C must be maintained.
The PK BIO 25 is designed to operate in conjunction with a buffer tank. A minimum reference value of 1,000 liters should be assumed. Buffer tank, return temperature control, pumps, expansion vessel, and safety devices must be matched to the heating load, system hydraulics, and operating mode.
Technical data at a glance
| Nominal output |
25 kW |
| Fuel |
dry split logs |
| Combustion technology |
Wood gasification / pyrolysis boiler |
| Efficiency |
90.0% |
| Boiler class |
Class 5 |
| Energy efficiency class |
A+ |
| Max. log length |
530 mm |
| Required chimney draft |
12–17 Pa |
| Flue pipe connection |
159 mm |
| Heating water connection |
2 inches |
| Max. operating pressure |
2 bar |
| Max. operating temperature |
90 °C |
| Minimum operating temperature |
63 °C |
| Electrical connection |
230 V / 50 Hz |
| Electrical power consumption |
max. 76 W / standby 3 W |
| Recommended buffer tank |
at least 1,000 l |
| Dimensions W × D × H |
784 × 923 × 1,186 mm without control lever; width incl. control lever 916 mm |
| Weight |
505 kg |
Installation
Installation, hydraulic connection, electrical supply, and flue gas connection must be carried out by qualified personnel. The chimney must be suitable for the required draft range of 12 to 17 Pa. When planning the installation, sufficient space must be provided for top loading, door opening, the operating lever for heat exchanger cleaning, and the required maintenance areas.
Notes
For proper wood gasification operation, sufficiently dry split logs are required. The minimum operating temperature of 63 °C must be maintained. The right-hand door hinge is the standard version; a left-hand hinged factory version can be selected when ordering. The flue gas outlet is vertical.
Scope of delivery
- ROJEK PK BIO 25 wood gasification boiler in selected door version
- Electronic boiler control
- Flue gas fan
- Integrated cooling loop
- Operating mechanism for heat exchanger cleaning
- Operating and installation instructions