Baxi 124 Combi - User Manual

Installation and Service Manual
Condensing Combination Boiler
124 - 128
Combi
en
United Kingdom
These instructions include the Benchmark Commissioning Checklist and should be left with the
user for safe keeping. They must be read in conjunction with the Flue Installation Guide.

Baxi 124 Combi Specifications

General

Boiler Type	Combi
ERP Rating	A
CH Output (kW)	24
DHW Output (kW)	24
Fuel	Natural Gas
Weight	31 kg
Mounting	Wall

Summary

The Benchmark Scheme

Building Regulations and the Benchmark Commissioning Checklist

Explains requirements for installing heating appliances per Building Regulations.

Installer Notification Guidelines

Legislation

IMPORTANT - Installation, Commissioning, Service & Repair

Key considerations for installing, commissioning, servicing, and repairing the appliance.

Homologations

Information regarding product conformity declarations and certifications.

Codes of Practice - refer to the most recent version

Lists relevant codes of practice for installation in GB and IE.

Safe Manual Handling

1.0 Introduction

1.1 Description

Provides a description of the boiler's features and capabilities.

1.2 Optional Extras

Lists optional accessories available for the boiler.

1.3 Contents of Pack

Details the items included in the boiler packaging.

2.0 General Layout

2.1 Layout

Illustrates the internal components and their locations within the boiler.

3.0 Appliance Operation

3.1 Central Heating Mode

Explains the boiler's operation during central heating demand.

3.2 Domestic Hot Water Mode

Describes the boiler's function for domestic hot water supply.

3.3 Boiler Frost Protection Mode

Details the automatic frost protection mechanism for the boiler.

3.4 Pump Protection

Explains the pump protection feature to prevent sticking.

4.0 Technical Data

4.1 124 & 128 Combi

Lists technical specifications for the 124 and 128 Combi models.

4.2 Technical Parameters

Provides detailed technical parameters for boiler combination heaters.

5.0 Dimensions and Fixings

6.0 System Details

6.1 Information

General information regarding water byelaws and installation requirements.

6.2 Treatment of Water Circulating Systems

Guidelines for system flushing, cleaning, and water treatment.

6.3 Bypass

Information on the boiler's integral bypass and external bypass requirements.

6.4 System Control

Discusses the use of external controls for optimal boiler operation.

6.5 System Filling and Pressurising

Procedures for filling and pressurising the central heating system.

6.6 Expansion Vessel (Central Heating only)

Details regarding the central heating expansion vessel.

6.7 Safety Pressure Relief Valve (Fig. 6)

Information on the safety pressure relief valve and discharge pipe.

6.8 Domestic Hot Water Circuit (Fig. 7)

Details of the domestic hot water circuit connections and requirements.

6.10 Hard Water Areas

Advice for installing the boiler in hard water areas.

7.0 Site Requirements

7.1 Location

Guidelines for selecting an appropriate location for boiler installation.

7.2 Clearances (Figs. 8 & 9)

Specifies required clearances around the boiler for installation and servicing.

7.3 Ventilation of Compartments

Information on ventilation requirements for boilers installed in compartments.

7.4 Gas Supply

Requirements for connecting the boiler to the gas supply.

7.5 Electrical Supply

Guidelines for connecting the boiler to the electrical supply.

7.6 Bath & Shower Rooms

Regulations regarding boiler installation in bathrooms and shower rooms.

7.7 Condensate Drain

Critical instructions for installing the condensate discharge pipework correctly.

7.8 Flue

Guidelines for siting the flue terminal safely and correctly.

8.0 Flue Options

8.1 Horizontal Flue Systems

Details of horizontal flue system installation and maximum lengths.

8.2 Flue Lengths

Information on telescopic flue kit lengths and extensions.

8.4 Terminal Guard (Fig. 15)

Guidance on the use and fitting of terminal guards.

9.0 Installation

9.1 Unpacking & Initial Preparation

Steps for unpacking the boiler and preparing for installation.

9.2 Flushing

Procedure for flushing the system before boiler installation.

9.3 Fitting The Boiler

Instructions for physically mounting and connecting the boiler.

9.4 Fitting the Pressure Relief Discharge Pipe (Fig. 22)

How to install the pressure relief discharge pipe.

9.5 Condensate Drain (see section 7.7) (Fig. 23)

Instructions for connecting the condensate drain pipe.

9.6 Fitting The Flue

Detailed steps for fitting the horizontal telescopic flue.

9.7 Making The Electrical Connections

Guide to wiring the boiler to the mains and external controls.

9.8 Preliminary Electrical Checks

Checks to perform on the electrical system before commissioning.

10.0 Commissioning

10.1 Commissioning the Boiler

Step-by-step guide for commissioning the boiler after installation.

10.2 Checking the Combustion - Chimney Sweep Function (cont)

Procedure for checking combustion performance.

10.3 Check the Operational (Working) Gas Inlet Pressure & Gas Rate

How to check gas pressure and rate for correct operation.

11.0 Completion & System Draining

11.1 Completion

Final steps after installation, including user handover.

11.2 System Draining

Instructions on how to drain the central heating system.

12.0 Servicing

12.1 Performance Safety Check & Annual Servicing

Safety checks and procedures for annual boiler servicing.

12.2 Annual Servicing Inspection (Cont)

Detailed inspection steps for annual boiler servicing.

13.0 Changing Components

13.1 Spark Ignition & Flame Sensing Electrodes (Fig. 49)

Instructions for replacing ignition and flame sensing electrodes.

13.2 Fan (Fig. 50)

Procedure for replacing the boiler fan assembly.

13.3 Air;Gas Venturi (Figs. 50 & 51)

Steps for changing the air/gas venturi component.

13.4 Burner (Fig. 52)

Guide for replacing the boiler burner.

13.5 Insulation (Fig. 53)

Instructions for replacing insulation components.

13.6 Flue Sensor (Fig. 54)

How to replace the flue sensor.

13.7 Heating Flow & Return Sensors (Fig. 55)

Instructions for replacing heating flow and return sensors.

13.8 Safety Thermostat (Fig. 55)

Steps for replacing the safety thermostat.

13.9 DHW NTC Sensor (Fig. 56)

Guide for replacing the domestic hot water NTC sensor.

13.10 Pump - Complete (Fig. 58)

Instructions for replacing the boiler pump.

13.12 Safety Pressure Relief Valve (Fig. 59)

How to replace the safety pressure relief valve.

13.14 Plate Heat Exchanger (Fig. 62)

Procedure for replacing the plate heat exchanger.

13.20 Gas Valve (Fig. 68)

Steps for replacing the gas valve, including calibration.

13.21 Expansion Vessel (Fig. 69)

Instructions for replacing the expansion vessel.

14.0 Combustion & Calibration

14.1 Checking the Combustion

Guide to checking and verifying combustion parameters.

14.2 Calibration Function

Procedure for calibrating the boiler's combustion settings.

14.3 Adjusting the CO2

How to adjust the CO2 levels for optimal combustion.

15.0 Electrical

15.1 Illustrated Wiring Diagram

Provides a wiring diagram for the boiler's electrical components.

16.0 Short Parts List

17.0 Fault Finding & ‘Service Due’

17.1 Initial Fault Finding Checks

Basic checks to perform when diagnosing boiler faults.

17.2 Error Codes

Explains common error codes displayed by the boiler.

Central Heating Fault Finding Flow

Flowchart to diagnose faults related to central heating operation.

Domestic Hot Water Fault Finding Flow

Flowchart to diagnose faults related to domestic hot water operation.

Fault Finding Solutions Sections A-E

Detailed fault finding steps and solutions for various issues.

Fault Finding Solutions Sections F-H

Further fault finding steps and solutions for various issues.

Fault Finding Solutions Sections I-M

Additional fault finding steps and solutions for various issues.

18.0 External Low Voltage Controls

18.1 Optional Outdoor Sensor & External Controls

Information on optional sensors and external control devices.

18.2 External Controls connected to M2

How external controls affect boiler operation.

18.3 Baxi Optional Outdoor Sensor

Guidelines for positioning the Baxi optional outdoor sensor.

18.4 Connecting the Optional Outdoor Sensor

Steps for connecting the optional outdoor sensor.

18.5 Setting the Sensor Curve

How to set the sensor curve for optimal performance.

18.6 Connecting the Optional 7 Day Wired Sensor

Instructions for connecting the 7-day wired sensor.

18.7 Connecting the Optional 7 Day Wireless Sensor & 24 hr Wireless Sensor

Guide for connecting wireless sensors and receivers.

19.0 ‘Service Due’ Message

GAS BOILER SYSTEM COMMISSIONING CHECKLIST

SERVICE RECORD