The Main Combi 24 HE is a wall-mounted, gas-fired combination boiler, approved under the Water Byelaws Scheme. This manual guides qualified technicians through installation and servicing procedures, ensuring compliance and optimal performance.
Boiler Overview and Key Features
The Main Combi 24 HE is a condensing combination boiler designed for domestic central heating and hot water provision. It’s approved to Water Byelaws Scheme standards, ensuring safe and efficient operation. Key features include its compact design for versatile installation locations and a user-friendly interface.
This boiler delivers a heating capacity of 24kW and a hot water flow rate suitable for typical household demands. The unit operates on natural gas (G.C. No 47 474 02) and requires a 230V 50Hz electrical supply. Its condensing technology enhances efficiency, reducing energy consumption and emissions.
Intended Use and Applications
The Main Combi 24 HE boiler is specifically designed for domestic central heating systems in small to medium-sized homes. It’s ideal for providing on-demand hot water, eliminating the need for a separate hot water storage cylinder. This combination boiler is suitable for installations where space is limited due to its compact dimensions.
Applications include central heating in apartments, terraced houses, and semi-detached properties. It’s intended for use with a sealed central heating system and is compatible with most standard radiators. The boiler is designed for indoor installation only, adhering to relevant safety regulations.
Safety Precautions
Installation and servicing must be performed by qualified personnel, adhering to all relevant gas and electrical safety regulations to prevent hazards and ensure safe operation.
General Safety Warnings
Prior to any work, carefully read and understand these instructions, alongside all applicable regulations. Incorrect installation can lead to unsafe operation and potential hazards. Always isolate gas, water, and electrical supplies before commencing work on the boiler. Ensure the installation environment is well-ventilated. Do not modify the boiler or use non-approved parts. Regular servicing is crucial for maintaining safety and efficiency. Keep these instructions readily available for future reference and handover to new occupants. Failure to follow these warnings could result in damage, injury, or even fatality.
Gas Safety Considerations
Gas safety is paramount. Installation must be carried out by a qualified and competent Gas Safe registered engineer, adhering to all current gas safety regulations. Verify gas tightness of all connections using a suitable leak detection fluid. Ensure adequate ventilation is provided to prevent carbon monoxide build-up. Check the gas supply pressure is within the specified limits for the Main Combi 24 HE. Never attempt to repair gas components; always replace them. Regular gas safety checks are essential for continued safe operation. Adhere to IRN 001 for specific requirements.
Electrical Safety Guidelines
Prioritize electrical safety during installation and servicing. Ensure the Main Combi 24 HE is electrically earthed correctly, as per wiring diagram instructions. Confirm the electrical supply is 230V 50Hz. Isolate the electrical supply before making any connections. Use appropriately rated cabling and ensure all connections are secure. Never work on live electrical components. Verify the integrity of the wiring and connections. Adhere to all relevant electrical regulations. Qualified personnel only should undertake electrical work. Regular checks of electrical connections are recommended.
Unpacking and Inspection
Carefully unpack the Main Combi 24 HE boiler and inspect for any damage sustained during transit. Report any issues immediately to your supplier for resolution.
Checking for Damage During Transit
Upon delivery, thoroughly examine the packaging for any signs of mishandling or impact damage. If the outer packaging appears compromised, carefully document the damage with photographs before opening. Once unpacked, inspect the boiler’s casing for dents, scratches, or other visible defects.
Check all components against the parts list to ensure nothing is missing. Any damage discovered during transit must be reported immediately to the carrier and your supplier. Retain all packaging materials as evidence for potential claims. Failure to report damage promptly may invalidate warranty claims.
Component Identification
The Main Combi 24 HE package includes the boiler unit itself, a mounting bracket for wall installation, and accompanying pipe connections. Key external components include the gas connection point, cold water inlet, central heating outlet, and condensate pipe connection. Familiarize yourself with the location of the control panel, displaying operational status and error codes.
Internally, crucial parts consist of the heat exchanger, fan, gas valve, and pump. Refer to the exploded diagram within the full installation manual for a detailed visual guide to each component’s position and function.
Installation Requirements
Installation must adhere to all relevant regulations and Water Byelaws. Qualified personnel should prepare the site, ensuring appropriate gas, water, and electrical supplies are available.
Site Preparation
Prior to installation, thoroughly assess the intended location for the Main Combi 24 HE boiler. The wall must be capable of supporting the boiler’s weight, even when fully pressurized with water. Ensure sufficient space around the unit for servicing and maintenance access, adhering to local regulations.
Verify adequate ventilation is present, complying with current gas safety standards. The floor should be level and capable of supporting any condensate discharge arrangements. Protect the area from potential water damage and ensure easy access to gas, water, and electrical connections.
Gas Supply Requirements
The Main Combi 24 HE is designed for use with Natural Gas and holds G.C. No 47 474 02; Ensure the gas supply is adequate for the boiler’s maximum input rate. A qualified Gas Safe registered engineer must verify the gas supply pressure is within the specified limits.
Gas pipe sizing must adhere to relevant regulations, utilizing appropriate materials. The connection to the gas supply should be made using a flexible gas connector, complying with industry standards. Always perform a gas tightness test after connection.
Water Supply Requirements
The Main Combi 24 HE requires a suitable water supply with adequate pressure and flow rate to meet both heating and hot water demands. The cold water supply must be connected via a flexible hose, adhering to Water Byelaws.
Ensure the system is thoroughly flushed before connection to remove any debris. The boiler’s cold water inlet connection must be made correctly to prevent leaks. Proper water pressure is crucial for efficient operation; initial system pressurization should be to 0.5 bar when cold.
Electrical Supply Requirements (230V 50Hz)
The Main Combi 24 HE operates on a 230V, 50Hz electrical supply. A dedicated, correctly fused electrical connection is essential for safe and reliable operation. Ensure the electrical supply complies with current regulations and is installed by a qualified electrician.
Correct earthing is paramount; verify the earthing connection is secure and meets safety standards. Before commencing any electrical work, isolate the power supply. Refer to the wiring diagram provided in the installation manual for correct connection details.
Boiler Mounting and Positioning
Secure wall mounting is crucial for the Main Combi 24 HE. Ensure adequate ventilation around the boiler, following the guidelines detailed within this installation manual.
Wall Mounting Instructions
Prior to mounting, verify the wall’s suitability to support the boiler’s weight, both when full of water and during operation. Use appropriate fixings, suitable for the wall construction, ensuring they meet relevant building regulations.
The boiler should be mounted vertically, using the provided mounting bracket. Mark the bracket positions accurately, drill pilot holes, and securely fasten the bracket to the wall. Carefully lift the boiler onto the bracket, ensuring it is correctly seated and locked into place. Double-check stability before proceeding.
Ensuring Adequate Ventilation
Proper ventilation is crucial for safe boiler operation, supplying fresh air for combustion and dispersing flue gases. The installation location must adhere to relevant building regulations regarding ventilation requirements for gas appliances.
Avoid obstructions to air inlets and outlets. Do not install the boiler in a confined space without adequate provision for air supply. Ensure any existing ventilation openings are not blocked or reduced in size. Regular checks should confirm continued adequate airflow to maintain safe and efficient operation.
Plumbing Connections
Plumbing installation requires connecting the cold water inlet, central heating outlet, and condensate pipe, ensuring secure and leak-proof joints for efficient system operation.
Cold Water Inlet Connection
Connect the cold water inlet using 22mm copper or plastic tubing, ensuring it’s fully supported and protected from freezing. A balanced flue installation is crucial. The connection must comply with relevant Water Byelaws.
Install a suitable isolating valve upstream of the boiler for maintenance purposes. Verify the water supply pressure is within the specified range before connecting. Avoid sharp bends in the pipework to prevent restrictions. Ensure all joints are watertight to prevent leaks and maintain system efficiency. Proper sealing is paramount.
Central Heating Outlet Connection
Connect the central heating outlet using 22mm copper pipe, ensuring adequate support and insulation to minimize heat loss. A balanced flue is essential for safe operation. The flow and return pipes must be correctly identified and connected to the corresponding boiler ports.
Install a suitable filter to protect the boiler from debris within the heating system. Ensure the pipework is free from airlocks after installation. Proper sizing of the pipework is crucial for optimal system performance and efficiency. Verify all connections are secure and leak-free.
Condensate Pipe Installation
Install the condensate pipe, typically 28mm PVC, with a continuous downward slope to facilitate drainage. This pipe removes acidic condensate produced during the boiler’s efficient operation. Ensure the pipe terminates in a safe and accessible location, preventing freezing or damage.
Avoid sharp bends or restrictions in the condensate pipe run. An air trap should be installed to prevent siphoning. The pipe must be installed according to local regulations and building codes, ensuring proper ventilation and preventing backflow. Securely fix the pipe to prevent movement.
Gas Connection
Connect to the gas supply using appropriately sized and approved pipework, ensuring a gas-tight seal. Adhere to all relevant gas safety regulations and standards.
Gas Pipe Sizing and Materials
Proper gas pipe sizing is crucial for safe and efficient boiler operation. Refer to current gas safety regulations and the manufacturer’s specifications for determining the correct pipe diameter based on the boiler’s gas consumption and pipe length.
Only use approved gas pipe materials conforming to relevant standards. Typically, steel or polyethylene (PE) pipes are suitable, but compatibility must be verified. Ensure all joints are gas-tight, utilizing appropriate fittings and sealing compounds.
The preferred minimum gas supply is essential for optimal performance, and any restrictions must be avoided. Always consult a qualified gas engineer for gas pipework installation and testing.
Connection to Gas Supply
Before connecting to the gas supply, isolate the gas supply to the property and purge the gas pipework to remove any air. Ensure the gas supply pressure is within the specified range for the Main Combi 24 HE boiler – consult the installation manual for precise values.
Connect the gas pipe to the boiler’s gas inlet using a suitable gas-tight connection.
After connection, conduct a gas tightness test using a suitable gas leak detection fluid, adhering to gas safety regulations. A qualified gas engineer must perform this test and issue a gas safety certificate upon successful completion.
Electrical Connections
The Main Combi 24 HE requires a 230V 50Hz electrical supply. Refer to the wiring diagram within the manual for correct connection and earthing procedures.
Wiring Diagram
Carefully consult the detailed wiring diagram provided within the Main Combi 24 HE Installation & Service Instructions Manual. This diagram illustrates the precise connections for the 230V 50Hz electrical supply. It clearly identifies the live, neutral, and earth terminals, crucial for safe and correct installation.
Ensure all wiring adheres to current IEE regulations. Incorrect wiring can lead to malfunction, damage to the boiler, or pose a serious safety hazard. Technicians must verify proper earthing to prevent electric shock. The diagram also details any internal wiring configurations specific to the Combi 24 HE model.
Earthing Requirements
A reliable earth connection is paramount for the safe operation of the Main Combi 24 HE boiler. The boiler must be connected to a dedicated earth terminal within the consumer unit, conforming to current IEE wiring regulations. This provides essential protection against electrical shock and ensures the boiler’s safety systems function correctly.
Verify the earth continuity using appropriate testing equipment before and after making the connection. The earth wire must be of adequate size and securely connected to the designated terminal on the boiler’s control panel. Failure to properly earth the boiler will invalidate the warranty.
Initial Boiler Setup and Commissioning
Post-installation, the system requires filling and pressurisation to 0.5 bar (cold). Gas rate adjustment and thorough system testing are crucial for safe, efficient operation.
Filling and Pressurising the System (0.5 bar cold)
Before operation, the central heating system must be thoroughly filled with water and pressurised. Ensure all automatic air vents are open during the filling process to facilitate air removal. The system pressure should be carefully monitored and adjusted to 0.5 bar when the boiler is cold.
Gradually open the filling loop valve until the desired pressure is reached, then close it securely. Check for any leaks throughout the system, including joints and connections. Insufficient pressure can lead to operational issues, while excessive pressure poses a safety risk. Regularly monitor the pressure gauge.
Gas Rate Adjustment
Correct gas rate adjustment is crucial for efficient and safe boiler operation. This process should only be undertaken by a qualified and competent gas engineer. Refer to the boiler’s technical data plate for the specified input rate. Using appropriate testing equipment, measure the gas flow rate and compare it to the required value.
Adjust the gas valve setting as necessary to achieve the correct input rate, ensuring compliance with safety regulations. Incorrect adjustment can lead to inefficient combustion, carbon monoxide production, or boiler malfunction. Always re-check the rate after adjustment.
System Testing and Verification
Post-installation, thorough system testing is essential to confirm correct operation. Verify the central heating system pressurizes to 0.5 bar when cold. Check hot water delivery at various taps, ensuring adequate temperature and flow rate. Inspect for any gas or water leaks around all connections.
Perform a combustion analysis to confirm efficient burning and safe flue operation. Cycle the boiler through its various modes, observing performance. Document all test results and address any identified issues before commissioning the system for the user.
Troubleshooting Common Issues
Common problems include no gas supply, low water pressure, and operational faults. Refer to page 39 of the manual for initial checks and diagnostic procedures.
No Gas Supply
If the boiler receives no gas, first verify the main gas supply is active and flowing to the property. Check the gas isolation valve near the boiler is fully open. Inspect the gas pipework for any kinks or damage that might restrict flow.
Ensure the gas rate adjustment is correctly set according to the boiler’s specifications. A qualified Gas Safe registered engineer must perform this adjustment. Confirm the gas supply pressure meets the requirements outlined in the installation manual. If issues persist, contact your gas supplier immediately for assistance.
Low Water Pressure
Experiencing low water pressure can indicate several issues. Initially, check the system pressure gauge on the boiler; it should ideally be between 0.5 and 1.0 bar when cold. If below 0.5 bar, repressurise the system using the filling loop, following the instructions in the manual.
Inspect for any water leaks in the central heating system, including radiators, pipes, and the boiler itself. A qualified engineer should investigate persistent low pressure, as it could signal a more significant system problem.
Fault Finding Checks (Page 39 ManualsLib)
Initial fault finding, as detailed on page 39 of the ManualsLib document, begins with verifying the availability of essential supplies. Confirm gas, water, and a 230V 50Hz electrical supply are reaching the boiler. Ensure the central heating water system is correctly pressurised to 0.5 bar when the boiler is cold.
The preferred minimum gas supply should be checked. These preliminary checks establish a baseline before proceeding with more complex diagnostic procedures, aiding in efficient troubleshooting.