The Vokèra Vision Plus is a high-efficiency system boiler designed for domestic heating and hot water systems. It is a room-sealed, fan-flued appliance, suitable for internal wall mounting. The boiler is available in three models: Vision Plus 20S, 25S, and 30S, with outputs ranging from 20kW to 30kW.
Function Description:
The Vision Plus boiler provides heated water to radiators and hot water taps. It features electronic ignition, a circulating pump, an expansion vessel, a safety valve, a pressure transducer, and an automatic by-pass. The central heating and hot water are controlled via a time clock and any fitted thermostats. The boiler lights electronically without a pilot light. In case of a fault, the gas supply to the burner is automatically terminated.
Important Technical Specifications:
- Dimensions: All models (20S, 25S, 30S) have a height of 740mm and a width of 420mm. The 20S model has a depth of 275mm, while the 25S and 30S models have a depth of 350mm.
- Clearances Required: Above: 100mm (or 25mm above flue bend if top flue outlet is used), Below: 200mm (can be reduced to 5mm if a removal panel allows 200mm for maintenance), Left Side: 2mm, Right Side: 2mm, Front: 450mm (or 4mm if a removal panel enables 450mm access for maintenance).
- Heat Output (60/80°C):
- Vision Plus 20S: Max 19.46 kW, Min 3.41 kW
- Vision Plus 25S: Max 24.38 kW, Min 4.65 kW
- Vision Plus 30S: Max 29.25 kW, Min 4.65 kW
- Heat Output (30/50°C):
- Vision Plus 20S: Max 21.30 kW, Min 3.71 kW
- Vision Plus 25S: Max 26.95 kW, Min 5.08 kW
- Vision Plus 30S: Max 32.25 kW, Min 5.08 kW
- Working Pressure: Minimum 0.25-0.45 bar, Maximum 3.0 bar.
- Gas Pressures (G20): Inlet pressure 20.0 mbar.
- Expansion Vessel: Capacity 9 litres, Maximum system volume 74 litres, Pre-charge pressure 1 bar.
- Electrical Supply: 230V @ 50Hz, protected by a 3-amp fuse. Power consumption for CH: 62W (20S), 68W (25S), 79W (30S).
- Flue Details (concentric 60-100mm): Max horizontal length 10.0m (20S), 6.0m (25S, 30S). Max vertical length 11.0m (20S), 7.0m (25S, 30S).
- Flue Details (concentric 80-125mm): Max horizontal length 25.0m (20S), 15.0m (25S, 30S). Max vertical length 26.0m (20S), 16.0m (25S, 30S).
- Efficiency (SEDBUK 2005): 90.04% (20S), 90.13% (25S, 30S).
- Emissions (G20):
- CO2 @ max output: 9.1% (20S, 30S), 9.0% (25S)
- CO2 @ min output: 9.0% (all models)
- CO @ max output: 130 ppm (20S), 120 ppm (25S), 150 ppm (30S)
- CO @ min output: 10 ppm (20S), 20 ppm (25S, 30S)
- NOx rating: Class 6 (all models)
Usage Features:
- Control Panel: Equipped with a large LCD display showing operating status, temperature, and fault codes.
- Parameter Access: Pressing the MENU key for 2 seconds provides access to the P1 menu for programming parameters like language, time, and scrolling text.
- Operating Modes:
- WINTER Mode: Boiler operates for heating. The delivery temperature is displayed, and the radiator icon blinks during a heating request.
- OFF Mode: Boiler is set to standby.
- Heating Water Temperature Adjustment:
- Without Outdoor Sensor: Setpoint can be adjusted between 40°C and 80.5°C for high-temperature systems, or 20°C and 45°C for low-temperature systems, in 0.5°C steps.
- With Outdoor Sensor: Delivery temperature is automatically adjusted based on outdoor temperature. Users can modify the comfort level within a range of -5 to +5.
- Frost Protection System: Built-in system activates if the temperature drops below 5°C, overriding time controls to protect the appliance. Requires a permanent electrical supply and a non-fault condition.
- Keyboard Lockout: Buttons 1+3 pressed for 2 seconds activate/deactivate keyboard lockout.
- Interface Standby: After 10 seconds of no heat request or key press, the display shows current time with blinking dots.
- Fault Codes: The display shows error codes and descriptions in case of malfunctions.
- Reset Function: Pressing key 2 (RESET) manually resets alarms, such as flame lockout.
- OTBus Remote Control: When connected, the boiler display shows "OTB," and some settings (OFF/WINTER status, heating setpoint) are controlled by the remote.
- Embedded Clock: Allows programming up to 4 ON/OFF time periods for heating, independently for each day or grouped for weekdays/weekends.
Maintenance Features:
- Routine Annual Servicing: Recommended annually by a competent person. Includes checking operation, performance, flue system, electrical apparatus, burner pressure, system design pressure, flue gas analysis, heat exchanger cleanliness, and condense trap.
- Cleaning the Primary Heat Exchanger: Involves removing the casing, disconnecting electrodes and fan power cables, removing the combustion unit, and vacuuming/brushing dirt residues. Avoid metal brushes and use natural white vinegar for stubborn deposits.
- Cleaning the Burner: Similar to heat exchanger cleaning, involves removing the casing, disconnecting electrodes and fan power cables, removing the combustion unit, and brushing the burner. Avoid metal brushes.
- Cleaning the Siphon: Remove the siphon, wash with detergent water. Avoid metal or pointed tools. Refill with water before restarting the boiler.
- Electrodes Verification: Check for wear and replace if deteriorated. Ensure correct positioning.
- Clapet Maintenance: Access the check valve by removing the fan. Check for foreign material and ensure correct opening/closing.
- Component Removal Procedure: Detailed instructions for removing and replacing various components like the pump assembly, safety valve, water pressure transducer, thermistors, PCB, gas valve, electrodes, expansion vessel, heat exchanger, transformer, combustion unit, fan and mixer, siphon, and interface.
- Gas Valve Calibration: Performed if necessary after combustion check, gas valve replacement, or gas type conversion. Involves adjusting maximum and minimum power adjustment screws.
- Range Rating: The boiler's maximum heat output can be adjusted to suit system requirements.
- Water Treatment: Vokèra recommends using an inhibitor suitable for stainless-steel heat exchangers to protect against corrosion and electrolytic action. Water treatment and flushing should comply with BS 7593 and Benchmark Guidance.
- Condensate Pipe Installation: Must comply with BS6798, using plastic drainage pipe with a minimum 45mm fall per meter for horizontal runs. External pipework must be insulated.
- Flue System: The fan-powered flue outlet can be rotated 360 degrees. Additional bends and extensions require reductions in maximum flue length. Ensure correct sealing and support.
To Next Page
Need help?
General