Table of Contents
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Installation and Servicing
Alpha CD12S/20S/28S
Range of Wall Mounted, Fan Assisted, Room Sealed,
Gas Fired, High Efficiency Condensing System Boilers
0051
Instructions
For Technical help or for Service call ...
ALPHA HELPLINE Tel: 0844 8718764
website: www.alpha-innovation.co.uk
Nepicar House, London Road,
Wrotham Heath, Sevenoaks,
Kent TN15 7RS
British Gas
Alpha CD12S
Alpha CD20S
Alpha CD28S
For use with Natural Gas only
Leave these instructions with the User
Service Listed
G.C. No. 41 532 16
G.C. No. 41 532 18
G.C. No. 41 532 20
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Table of Contents
Related Manuals for Alpha CD20S
Summarization of Contents
Technical Data
Performance - Natural Gas
Performance data for Natural Gas, including input, output, pressure, and gas rate.
System
Details on system pressure, temperature, relief valve, expansion vessel, and connections.
Components
Lists major internal boiler components like burner, heat exchanger, and sensors.
Electrical
Power supply, fuses, consumption, and electrical safety requirements.
Installation Parameters
Key installation parameters like clearances, flue terminal size, and hole requirements.
Performance Data
Boiler efficiency, SAP efficiency rating, and NOx class.
Flue Lengths
Formulas and maximum lengths for different flue configurations and bends.
Electrical Connections
Wiring details for optional clock kits and general electrical connections.
Boiler Schematic
Diagram illustrating boiler components and their layout with numbered references.
General Boiler Information
Gas Supply
Boiler gas rates, supply pipe size, and gas tightness testing requirements.
Electrical Supply
Boiler voltage, earthing, isolator, cable specs, and socket types for safe operation.
Air Supply
Requirements regarding air circulation for boiler cooling and installation clearances.
Flue System
Guidelines for flue installation, sloping, support, and available flue components.
Flue Terminal Location
Specifies minimum distances for flue terminal placement relative to openings and boundaries.
Boiler Location
Guidance on suitable locations, wall mounting, and room-specific installation requirements.
Central Heating System
Requirements for sealed central heating systems, including pressure and vessel sizing.
Filling the Central Heating System
Procedures for filling the system, setting pressure, and checking for leaks.
Flushing the Heating System
Essential steps for cleaning and flushing systems to maintain warranty and performance.
Disposal of Condensate
Requirements for safe disposal of condensate, including pipework and termination.
Installation
Unpacking
Lists the required boxes and their contents for boiler installation.
Clearances Required
Specifies minimum clearances around the boiler for safe installation and servicing.
Prepare the Wall
Instructions for marking and drilling the wall for mounting bracket and flue hole.
Fit the Boiler
Guidance on lifting, positioning, and securing the boiler onto the mounting bracket.
Connect the Pipework
Steps for flushing pipework, connecting flow, return, and gas lines.
Fit the Flue
Procedures for fitting the Easy-Flue to rear or side exit configurations.
Reducing the Flue
Instructions for shortening flue sections when the required length is less than minimum.
Extending the Flue
Guidance on assembling and fitting flue extensions and support brackets.
Fit Plume Management Components (Optional)
Instructions for optional components to manage exhaust plume emission.
Connect the Mains Supply
Steps for safely connecting the boiler to the mains electrical supply.
Fit the Clock Kit
Instructions for installing an optional Alpha two-channel clock.
Commissioning
Fill the System
Procedure for filling the central heating system, venting radiators, and checking pressure.
Boiler Controls
Identifies key controls and indicators on the boiler's front panel.
Test for Gas Tightness and Purge the Supply
Critical safety checks for gas supply integrity and purging air from the lines.
Initial Lighting
Steps for safely lighting the boiler for the first time and initiating operation.
Check the Burner Pressures
Procedure for verifying correct burner gas pressures for optimal performance.
Final Commissioning
System balancing, flushing, and repressurising after initial setup.
Final Assembly
Securing panels, setting controls, and completing the Benchmark Checklist.
User Information
Key points to explain to the user regarding operation, servicing, and safety.
Boiler Operation
Central Heating Mode
Explanation of how the boiler functions in central heating mode, including burner modulation.
Frost Thermostat
Description of the frost thermostat's operation to prevent freezing.
Pump Operation
Details on the automatic pump operation to prevent seizure.
Indicator Neons
Interpretation of the LED indicators for diagnosing operational status and faults.
Routine Servicing
Important Notes Prior to Servicing
Essential checks and safety precautions before commencing boiler servicing.
Combustion Check
Procedure for measuring and verifying combustion performance with a flue gas analyser.
Component Replacement
General Access
Steps for safely accessing internal boiler components for maintenance or repair.
Draining the Boiler
Instructions for draining the heating circuit prior to replacing components.
Electrodes
Procedure for replacing ignition and flame sensing electrodes.
Main Burner
Steps for removing and replacing the boiler's main burner assembly.
Burner Injector
Procedure for replacing the burner injector, a key fuel delivery component.
Fan
Steps for removing and replacing the boiler's fan assembly.
Ignition Generator
Procedure for replacing the ignition generator unit.
Transformer
Steps for replacing the internal transformer.
Overheat Thermostat
Procedure for replacing the overheat thermostat.
Flue Temperature Sensor
Steps for replacing the flue temperature sensor.
Gas Valve
Procedure for replacing the gas valve, requiring qualified personnel.
Terminal Block Fuse
Instructions for replacing the fuse located in the terminal block.
PCB
Procedure for replacing the Printed Circuit Board (PCB).
Clock (if fitted)
Instructions for replacing an optional two-channel clock.
Heat Exchanger Thermal Fuse
Procedure related to the thermal fuse or heat exchanger replacement.
Primary Heat Exchanger
Steps for removing and replacing the primary heat exchanger.
Combustion Chamber Insulation
Instructions for replacing front and back panel insulation for the combustion chamber.
Pressure Gauge
Procedure for replacing the system pressure gauge.
Primary Temperature Sensor
Steps for replacing the primary temperature sensor.
Automatic Air Vent
Procedure for replacing the automatic air vent.
Pump
Steps for replacing the boiler's circulation pump.
Primary Pressure Switch
Procedure for replacing the primary pressure switch.
Pressure Relief Valve
Steps for replacing the pressure relief valve.
Expansion Vessel
Procedure for replacing the expansion vessel.
Cyclone (if wall jig is fitted)
Steps for replacing the cyclone if fitted with the wall jig.
Condensate Trap
Procedure for replacing the condensate trap.
Wiring Diagrams
Illustrated Wiring Diagram
Visual representation of the boiler's electrical connections and component layout.
Functional Flow Wiring Diagram
Diagram showing the functional flow of electrical signals and components.
Fault Finding
Carry Out Initial Fault Finding Checks
Essential initial checks for gas, water, electrical supplies, and external controls.
Central Heating - Follow Operational Sequence
Flowchart for diagnosing central heating operational faults based on sequence.
Fault Finding Solutions A to D
Detailed troubleshooting steps for common faults indicated by specific neon patterns.
Fault Finding Solutions E to J
Detailed troubleshooting steps for faults related to ignition, sensors, and pressure switches.
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