Installation & Servicing Instructions Megaflo 2 System Compact GA Range Gas Fired Wall Mounted Condensing System Boiler These instructions include the Benchmark Commissioning Checklist and should be left with the user for safe keeping.
Model Range Baxi Megaflo 2 System 12 Compact GA G.C.No 41-075-70 Baxi Megaflo 2 System 15 Compact GA G.C.No 41-075-71 Baxi Megaflo 2 System 18 Compact GA G.C.No 41-075-72 Baxi Megaflo 2 System 24 Compact GA G.C.No 41-075-73 Baxi Megaflo 2 System 28 Compact GA G.C.No 41-075-74 Baxi Megaflo 2 System 32 Compact GA G.C.No 41-075-75 The Benchmark Scheme Benchmark places responsibilities on both manufacturers and installers.
Installer Notification Guidelines Choose Building Regulations Notification Route Competent Person's Self Certification Scheme Building Control Install and Commission this appliance to manufacturer's instructions Contact your relevant Local Authority Building Control (LABC) who will arrange an inspection or contact a government approved inspector Complete the Benchmark Checklist If you notify via the ‘Gas Safe Register’, the register will issue the Building Regulations certificate on members’ behalf
Legislation IMPORTANT - Installation, Commissioning, Service & Repair This appliance must be installed in accordance with the manufacturer’s instructions and the regulations in force. Read the instructions fully before installing or using the appliance. In GB, this must be carried out by a competent person as stated in the Gas Safety (Installation & Use) Regulations.
Safe Manual Handling General The following advice should be adhered to, from when first handling the boiler to the final stages of installation, and also during maintenance. Most injuries as a result of inappropriate handling and lifting are to the back, but all other parts of the body are vulnerable, particularly shoulders, arms and hands. Health & Safety is the responsibility of EVERYONE. There is no ‘safe’ limit for one man - each person has different capabilities.
CONTENTS Section 6 © Baxi Heating UK Ltd 2014 Page 1.0 Introduction 7 2.0 General Layout 8 3.0 Appliance Operation 9 4.0 Technical Data 10 5.0 Dimensions and Fixings 11 6.0 System Details 12 7.0 Site Requirements 14 8.0 Flue 19 9.0 Installation 21 10.0 Commissioning 26 11.0 Completion & System Draining 30 12.0 Servicing 31 13.0 Changing Components 33 14.0 Combustion & Calibration 40 15.0 Electrical 41 16.0 Short Parts List 42 17.0 Fault Finding 43 18.
The 12 to 28 kW models in the Baxi Megaflo 2 System Compact GA Range are of the same dimensions and layout. The 32 kW model differs in several respects - these are detailed in Section 18.0 ‘32 kW Model Supplement’ 1.0 Introduction 1.1 Description 1. The Baxi Megaflo 2 System Compact GA Range are fully automatic gas fired wall mounted condensing system boilers. They are room sealed and fan assisted. 2. The boiler is set to give a maximum output of :12 models - 12 kW 12.
2.0 General Layout 2.1 Layout 12 - 28 Models 3 4 2 1 11 10 1. Expansion Vessel 2. Expansion Vessel Locating Stud 3. Boiler Adaptor 4. Primary Heat Exchanger 5. Pump with Automatic Air Vent 6. Central Heating System Pressure Gauge 7. Fan Assembly 8. Flame Sensing Electrode 9. Air/Gas Collector 10. Spark Ignition Electrode 9 11. Combustion Box Cover & Burner 8 12. Condensate Trap 13. Safety Pressure Relief Valve 14. Boiler Control 15. Gas Valve 16. Boiler Drain Tap 17.
13 3.0 Appliance Operation 3.1 14 12 Operating Mode 1. With a demand for heating, the pump circulates water through the primary circuit. 15 2. Once main burner ignites the fan speed controls the gas rate to maintain the heating temperature measured by the temperature sensor. 16 3. When the flow temperature exceeds the setting temperature, a 3 minute delay occurs before the burner relights automatically (anti-cycling). The pump continues to run during this period. 17 18 4.
4.0 Technical Data 4.1 Appliance Category CAT I 2H 3P Electrical Supply 230V~ 50Hz (Appliance must be connected to an earthed supply) Heat Input CH (Net) 12 model kW 15 model kW 18 model kW 24 model kW 28 model kW Max 12 15 18 24 28 Power Consumption 12 model W 15 model W 18 model W 24 model W 28 model W C13 C33 C43 C53 Min 2.1 2.2 2.6 3.5 4.1 Min 2 2.1 2.5 3.4 4 Heat Output CH (Condensing) Max 12 model kW 12.7 15 model kW 15.9 18 model kW 19 24 model kW 25.4 28 model kW 29.6 Min 2.2 2.3 2.8 3.
5.0 Dimensions and Fixings Dimensions At least 1.5° G E A 700mm B 300*mm *This can be reduced to 290mm by removing the boiler control access flap A C 390mm D 116mm Ø Min. E 160mm (207mm for 80/125mm flue systems) B F 130mm 360° Orientation G 106mm H D C H 228mm J J 162mm Flue Ø 100mm F Tap Rail Boiler Side Boiler Side Condensate Drain 40 mm Pressure Relief Valve (15mm) 25 mm 130 mm 130 mm 65 mm 162.
6.0 System Details 6.1 Treatment of Water Circulating Systems 1. All recirculatory water systems will be subject to corrosion unless they are flushed and an appropriate water treatment is applied. To prevent this, follow the guidelines given in BS 7593 “Treatment of Water in Domestic Hot Water Central Heating Systems” and the treatment manufacturers instructions. 2.
6.0 System Details 6.4 Stop Valve Double Check Valve 1. A filling point connection on the central heating return pipework must be provided to facilitate initial filling and pressurising and also any subsequent water loss replacement/refilling. Stop Valve Fig. 4 DHW Mains Inlet Temporary Loop System Filling and Pressurising CH Return 2. The filling method adopted must be in accordance with all relevant water supply regulations and use approved equipment. 3.
390mm 5mm Min 7.0 Site Requirements 5mm Min 7.1 175mm Min (300mm Min if using 80/125mm flueing system) Location 1. The boiler may be fitted to any suitable wall with the flue passing through an outside wall or roof and discharging to atmosphere in a position permitting satisfactory removal of combustion products and providing an adequate air supply. The boiler should be fitted within the building unless otherwise protected by a suitable enclosure i.e. garage or outhouse.
7.0 Site Requirement 7.4 Gas Supply 1. The gas installation should be in accordance with the relevant standards. In GB this is BS 6891 (NG) or BS 5482 Pt. 1 (LPG). In IE this is the current edition of I.S. 813 “Domestic Gas Installations”. 2. The connection to the appliance is a 22mm copper tail located at the rear of the gas service cock (Fig. 10). 3.
Examples are shown of the following methods of termination:i) to an internal soil & vent pipe ii) via an internal discharge branch (e.g. sink waste) downstream of the trap iii) to a drain or gully iv) to a purpose made soakaway v) pumped into an internal discharge branch (e.g. sink waste) downstream of the trap vi) pumped into an external soil & vent pipe vii) to a drain or gully with extended external run & trace heating It is strongly recommended to discharge internally into the household drainage system.
v) pumped into an internal discharge branch (e.g. sink waste) downstream of the trap Sink 50mm 7.0 Site Requirement per me tre of p ipe run 2.5° M inimum fall Pipe must terminate above water level but below surrounding surface. Cut end at 45° 7.7 Condensate Drain (cont.) 12. A boiler discharge pump is available, ‘MULTIFIT’ part no. 720648301. This pump will dispose of both condensate & high temperature water from the relief valve. It has a maximum head of 5 metres.
Terminal Position with Minimum Distance (Fig. 12) (mm) A1 Directly below an opening, air brick, opening windows, etc. B1 Above an opening, air brick, opening window etc. C1 Horizontally to an opening, air brick, opening window etc. D2 Below gutters, soil pipes or drain pipes. E2 Below eaves. F2 Below balconies or car port roof. G2 From a vertical drain pipe or soil pipe. H2 From an internal or external corner. I Above ground, roof or balcony level. J From a surface or boundary line facing a terminal.
8.0 Flue 8.1 Horizontal Flue Systems 1. The standard flue is suitable only for horizontal termination applications. (ii) (i) 2. All fittings should be fully engaged. The approximate engagement is 40mm. Apply the lubricant supplied to the seal on each fitting to aid assembly. 3. Maximum permissible equivalent flue lengths are:(60/100) (80/125) Horizontal Concentric 10 metres 20 metres 4. Any additional “in line” bends in the flue system must be taken into consideration.
8.0 Flue 8.2 Flue Lengths The standard horizontal telescopic flue kit allows for lengths between 315mm and 500mm from elbow to terminal (Fig. 14). Extensions of 250mm, 500mm & 1m are available. m The maximum permissible equivalent flue length is: 10 metres (60/100 system - vertical & horizontal) 20 metres (80/125 system - vertical & horizontal) 15 metres (80/80 twin pipe) 8 metres (60/100 system - vertical connected to ridge terminal) 0m 50 m 5m 31 Flue Deflector Fig.
9.0 Installation 9.1 Unpacking & Initial Preparation IMPORTANT RISK ASSESSMENT - Before commencing the installation it is recommended that the ‘Five Steps to Risk Assessment’ document published by the HSE is consulted, and an assessment performed as described. GAS SUPPLY - The gas supply, gas type and pressure must be checked for suitability before connection (see Section 7.4). NOTE: a small amount of water may drain from the boiler in the upright position.
Boiler Mounting Bracket 9.0 Installation 9.3 Fitting The Boiler 1. Remove the sealing caps from the boiler connections. NOTE: A small amount of water may drain from the boiler once the caps are removed. Sealing Washers 2. Lift the boiler as indicated by the shaded areas. The boiler should be lifted by TWO PEOPLE. Engage the mounting bracket at the top rear of the boiler on the wall plate (Fig.21) (see Safe Manual Handling page 5). 3.
9.0 Installation m 0m 50 m 5m 31 9.6 Fitting The Flue HORIZONTAL TELESCOPIC FLUE Terminal Assembly Connection Assembly Fig. 24 1. There are two telescopic sections, the Terminal Assembly and the Connection Assembly, a roll of sealing tape and two self tapping screws. A 93° elbow is also supplied. The outer duct of the Connection Assembly is painted white. On the Terminal Assembly the outer duct is unpainted. 2. The two sections can be adjusted to provide a length between 315mm and 500mm (Fig.
9.0 Installation Flue Elbow Apply the lubricant supplied for ease of assembly (do not use any other type). 9.6 Ensure Flue Elbow is fully engaged into Boiler Adaptor Fitting the Flue (Cont) 10. Remove the flue elbow and insert the flue through the hole in the wall. Boiler Adaptor 11. Refit the elbow to the boiler adaptor, ensuring that it is pushed fully in (Fig. 29). 12. Two flue trims are supplied, one for internal use, the other for outside.
9.0 Installation 9.7 Making The Electrical Connections 1. See Section 7.5 for details of the electrical supply. Undo the securing screws and lift the case front panel off. 2. Disengage the securing tab and hinge the control box downwards. Undo the terminal block cover securing screw and remove the cover (Fig. 32). 3. Slacken the gland nut in the left of the boiler lower panel and pass the mains cable through it.
11.0 Commissioning 10.0 10.1 Cap Commissioning the Boiler 1. Reference should be made to BS:EN 12828, 12831 & 14336 when commissioning the boiler. Ensure that the trap has been primed - see Section 9.5 paragraph 3. Automatic Air Vent 2. At the time of commissioning, complete all relevant sections of the Benchmark Checklist at the rear of this publication. 3. Ensure that the filling loop is connected and open, then open the heating flow and return valves on the boiler.
