1. Manuals
  2. Brands
  3. Main Heating Manuals
  4. Boiler
  5. Main Heat 12
  6. Installation & service manual

Main Heating Main Heat 12 Installation & Service Manual

Condensing central heating boiler
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
7219628 - 01 (4/15)
United Kingdom
Main Heat 12 - 15 - 18 - 24 - 30
Condensing Central Heating Boiler
Installation & Service Manual
These instructions include the Benchmark Commissioning Checklist and should be left with the user for safe keeping.
page 1
Building Regulations and the Benchmark Commissioning Checklist
Building Regulations (England & Wales) require notification of the installation of a heating appliance to the relevant Local Authority Building Control
Department. From 1 April 2005 this can be achieved via a Competent Persons Self Certification Scheme as an option to notifying the Local Authority directly.
Similar arrangements will follow for Scotland and will apply in Northern Ireland from 1 January 2006.
The Health & Safety Executive operates the 'Gas Safe Register', a self-certification scheme for gas heating appliances.
These arrangements represent a change from the situation whereby compliance with Building Regulations was accepted as being demonstrated by
completion of the Benchmark Logbook (which was then left on site with the customer).
With the introduction of Self Certification Schemes, the Benchmark Logbook is being withdrawn. However, a similar document in the form of a commissioning
checklist and service interval record is incorporated at the back of these instructions.
This company is a member of the Benchmark initiative and fully supports the aims of the programme. Its aim is to improve the standards of installation and
commissioning of central heating systems in the UK and to encourage the regular servicing of all central heating systems to ensure safety and efficiency.
Building Regulations require that installations should comply with manufacturer's instructions. It is therefore important that the commissioning checklist is

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the Main Heat 12 and is the answer not in the manual?

Questions and answers

Related Manuals for Main Heating Main Heat 12

Summary of Contents for Main Heating Main Heat 12

  • Page 1 7219628 - 01 (4/15) United Kingdom Main Heat 12 - 15 - 18 - 24 - 30 Condensing Central Heating Boiler Installation & Service Manual These instructions include the Benchmark Commissioning Checklist and should be left with the user for safe keeping.
  • Page 2 completed by the installer. The relevant section of Building Regulations only relates to dwellings. Therefore the checklist only applies if the appliance is being installed in a dwelling or some related structure. The flowchart below gives guidance for installers on the process necessary to ensure compliance with Building Regulations. Natural Gas Main 12 Heat ErP G.C.No 41-467-23...
  • Page 3 page 3 Legislation This company declares that no substances harmful to health are contained in the appliance or used during appliance manufacture. The appliance is suitable only for installation in GB and IE and should be installed in accordance with the rules in force, and only used in a suitably ventilated location.
  • Page 4 Gas Safety (Installation & Use) Regulations. The appropriate Building Regulations either The Building Regulations, The Building Regulations (Scotland), Building Regulations (Northern Ireland). The Water Fittings Regulations or Water Byelaws in Scotland. The Current I.E.E. Wiring Regulations. Where no specific instructions are given, reference should be made to the relevant British Standard Code of Practice. In IE, the installation must be carried out by a competent Person and installed in accordance with the current edition of I.S.

  • Page 5: Table Of Contents

    hands. Health & Safety is the responsibility of EVERYONE. There is no 'safe' limit for one man - each person has different capabilities. The boiler should be handled and lifted by TWO PEOPLE. Do not handle or lift unless you feel physically able. Wear appropriate Personal Protection Equipment e.g.
  • Page 6 19.27 kW Pnc (Condensing) 24 - 22.0 kW Pn (Non condensing) 23.8 kW Pnc (Condensing) 30 - 30.18 kW Pn (Non condensing) 32.61 kW Pnc (Condensing) All boilers automatically adjust their outputs according to the system load. NOTE: The maximum output of the 30 model is factory set at 22.0 kW (Pn). This can be altered to 30.18 kW (Pn).

  • Page 7: General Layout

    Contents of Pack The pack contains:- Boiler Wall Plate Template & 'Quick Fit' Guide Literature Pack Fittings Pack 1.2 Important Information Man-made mineral fibre Some component parts of this appliance (insulation pads, gaskets and rope seals) are manufactured from man-made mineral fibre. Prolonged or excessive exposure to this material may result in some irritation to the eyes, skin or respiratory tract.
  • Page 8 Fig. 3, Fig. 4, Fig. 5 & Fig. 6...

  • Page 9: Appliance Operation

    page 8 3.0 Appliance Operation 1. Switched Live On: When the switched live switches on if the flow temperature is less than the set point then pump overrun occurs. When the switched live switches on if the flow temperature is greater than the set point then pump overrun occurs. 2.

  • Page 10: Technical Data

    page 9 4.0 Technical Data 4.1 Main 12, 15, 18, 24, 30 Heat ErP C 13 C 33 C 53 Appliance Type CAT I 2H Appliance Category Heat Input Qn Hs (Gross) 12 model 13.34 10.2 15 model 16.88 10.2 18 model 20.18 10.2...
  • Page 11 24 model - The efficiency is 88.8 % 30 model - The efficiency is 88.8 % This value is used in the UK Government's Standard Assessment Procedure (SAP) for energy rating of dwellings. The test data from which it has been calculated has been certified by 0086.
  • Page 12 fully pumped open vented & sealed systems Gas Connection G 1/2"​ B.S.P. Thread Controls boiler thermostat, safety thermostat, flow switch, electronic flame sensing, temperature protection thermostat & condensate blockage sensor Inlet Pressure at Gas Valve (Natural Gas) 18.1 mbar 22.5 mbar (see Section 12.1)

  • Page 13: Dimensions And Fixings

    Ignition burner power consumption P ign 10550 13187 15652 20870 26087 Annual energy consumption Sound power level, indoors Emissions of nitrogen oxides mg/kWh (1) Low temperature means for condensing boilers 30°C, for low temperature boilers 37°C and for other heaters 50°C return temperature (at heater inlet). (2) High temperature regime means 60°C return temperature at heater inlet and 80°C feed temperature at heater outlet.

  • Page 14: System Details

    The 1.5° fall provided by the elbow is to allow condensate to run back to the boiler, for disposal through the condensate discharge pipe. Fig. 8 SIDE FLUE (left and right) For every 1m of horizontal flue length, the clearance above the top of the flue elbow should be 27.5mm to incorporate the 1.5°...
  • Page 15 from the boiler and include any branches (Fig. Fig. 9 Fig. 10 6.4 Low Head Installation 1. Using a close couple arrangement the minimum head is as shown in the diagrams (Figs. 10 & 11) subject to the following conditions: a) The pump being adjusted to give a 20°C drop across the boiler.
  • Page 16 Fig. 12 6.5 Pump 1. Providing that the cold feed and open vent pipe are positioned correctly (e.g. the system is not prone to pumping over, air entrainment etc.) the pump may be fitted on the primary return pipe. page 14 6.6 System Controls This boiler does not require a bypass.
  • Page 17 S Plan, Room Thermostat System, CH Interlocked By Room Thermostat At least the Radiator(s) near the Room Thermostat not TRV'd Pump run from Switched Live By-pass permitted but not required for Part L1 compliance Y Plan, Fully TRV'd System, CH Interlocked By Boiler Flow Switch Room Thermostat should not be fitted Pump must be run from Boiler P/F connection for Part L1 compliance By-pass not permitted (must be valved off) for Part L1 compliance...
  • Page 18 page 15 6.7 Sealed Systems (Fig. 1. SAFETY VALVE - A safety valve complying with the requirements of BS 6750 Part 1 must be fitted close to the boiler on the flow pipe by means of a horizontal or vertically upward connection with no intervening valve or restrictions and should be positioned to facilitate testing. The valve should be pre-set and non-adjustable to operate at a pressure of 3 bar.

  • Page 19: Site Requirements

    NOTE Where a vessel of the calculated size is not obtainable then the next available larger size should be used. Fig. 14 page 16 7.0 Site Requirements 7.1 Location NOTE: Due to the high efficiency of the boiler a plume of water vapour will be discharged from the flue. This should be taken into account when siting the flue terminal.
  • Page 20 3. Any compartment should be large enough to house the boiler only. NOTE: The ventilation label on the front of the outer case MUST NOT BE REMOVED when the appliance is installed in a compartment or cupboard. Fig. B page 17 7.3 Clearances (Figs.
  • Page 21 Fig. 16 7.4 Gas Supply 1. The gas installation should be in accordance with the relevant standards. In GB this is BS 6891. In IE this is the current edition of I.S. 813 "Domestic Gas Installations"​ . 2. The connection to the appliance is a 1/2in BSPF. 3.
  • Page 22 suitable condensate pump in basement and cellar or similar applications. The boiler condensate trap incorporates a seal of 75mm, therefore it is unnecessary to install an air break and trap in the discharge pipework. 1. The condensate outlet will accept 21.5mm ( in) plastic overflow pipe.
  • Page 23 iii) Termination to a drain or gully iv) Termination to a purpose made soakaway Further specific requirements for soakaway design are referred to in BS 6798. page 19 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.
  • Page 24 14. It is possible to fit the element externally on the condensate drain or internally as detailed in the instructions provided. 15. The fitting of a 'Trace Heating' Element is NOT a substitute for correct installation of the condensate drain. ALL requirements in this section must still be adhered to.
  • Page 25 page 20 7.7 Flue NOTE: Due to the high efficiency of the boiler a plume of water vapour will be discharged from the flue. This should be taken into account when siting the flue terminal. 1. The following guidelines indicate the general requirements for siting balanced flue terminals. For GB recommendations are given in BS 5440 Pt.1. For IE recommendations are given in the current edition of I.S.
  • Page 26 Horizontally from a terminal on the same wall. From adjacent wall to flue (vertical only). From an adjacent opening window (vertical only). 1000 Adjacent to windows or openings on pitched and flat roofs Below windows or openings on pitched roofs 2000 In addition, the terminal should be no nearer than 150 mm to an opening in the building fabric formed for the purpose of accommodating a built-in element such as a window frame.

  • Page 27: Flue Options

    Fig. 17b page 21 8.0 Flue Options 8.1 Horizontal Flue Systems Concentric The maximum equivalent lengths are 4m (horizontal) or (vertical). Their lengths exclude the standard elbow and flue/terminal assembly (horizontal) and terminal assembly (vertical). Any additional "in line"​ bends in the flue system must be taken into consideration. Their equivalent lengths are: Concentric Pipes: 45°...
  • Page 28 NOTE: Horizontal flue pipes should always be installed with a 1.5° fall from the terminal to allow condensate to run back to the boiler. page 22 8.2 Twin & Vertical Flue Systems Concentric The maximum equivalent lengths are 4m (vertical). Their lengths exclude the standard elbow and terminal assembly (vertical). Twin Flue The total maximum equivalent flue length is 150m.
  • Page 29 Concentric Pipes: 135° bend 0.5 m 93° bend 1.0 m Twin Flue Pipe: 135° bend (air duct) 1.3 m 135° bend (flue duct) 2.6 m 90° bend (air duct) 4.8 m 90° bend (flue duct) 9.6 m IMPORTANT: All flue systems must be securely supported at least once every metre. Suitable pipe supports are available as accessories.
  • Page 30 The total equivalent length for this example is 17.2 + 34.4 = 51.6 metres. AIR DUCT Equivalent No of Sub total Length Value fittings/pipes 1m extension 5.0m 135°bend 1.3m 2.6m 91.5°bend 4.8m 9.6m Equivalent Length Air Duct = 17.2m FLUE DUCT Equivalent No of Sub total...
  • Page 31 page 23 8.3 Flue Accessories Key Accessory Size Code No FLUE GROUP B Concentric Flue System 110mm diameter A1 Horizontal Flue Terminal 850mm 243013BAX Horizontal Flue Terminal (incl elbow) 236921 Flue Extension 1000mm 241695 500mm 241694 250mm 241692 Flue Bend 93°...
  • Page 32 page 24 8.4 For Vertical Flue Systems 1. Undo the screws securing the blanking plate to the boiler top panel. Discard the plate. 2. Fix the vertical adaptor and gasket to the top panel with the previously removed screws. 8.5 For Twin Flue Systems 1.
  • Page 33 For Twin Flues page 25 8.6 For Roof Terminals 1. In the case of a pitched roof 25 - 50 degrees, position the lead tile to replace/flash over existing roof tiling. Make an aperture in the roof suitable for the lower tube of the roof terminal and ensure the integrity of the roof cover is maintained.
  • Page 34 8.7 Flue Dimensions The standard horizontal flue kit allows for flue lengths between 270mm (10 "​ ) and 800mm (32"​ ) from elbow to terminal (Fig. 18). The maximum permissible equivalent flue length is: 4 metres. NOTE: Each additional 45° of flue bend will account for an equivalent flue length of 0.5m. e.g.

  • Page 35: Plume Displacement

    8.8 Terminal Guard (Fig. 1. When codes of practice dictate the use of terminal guards, they can be obtained from most Plumbers' and Builders' Merchants. 2. When ordering a terminal guard, quote the appliance model number. 3. The flue terminal guard should be positioned centrally over the terminal and fixed as illustrated. Fig.
  • Page 36 7. 70Ø 1 metre extensions (including support bracket), and additional 93° & 45° elbows are available. Any additional 93° & 45° elbows must be accounted for when calculating flue lengths. 70Ø 93° elbows are equivalent to 3.5 metres of straight length and 45° elbows to 1 metre. NOTE: Permitted positions of the plume outlet relative to doors, windows etc.
  • Page 37 Fig. C page 27 9.2 Determining Permissible Lengths - P.D.K. In the graph the solid line diagonal represents the relationship between the concentric flue assembly (and any extensions) and the 70Ø exhaust (and any extensions or additional bends). Example 1 - Not Permissible If, for instance, a concentric length of 3.25 metres was required and the 70Ø...
  • Page 38 Example 1 Example 2 Example 3...
  • Page 39 Fig. D Flue Length - Worked Example Main 30 Heat Fig. D Above an additional 93° elbow and pair of 45° elbows have been included in the 70Ø exhaust. Also 3 straight extension pieces have been used. To calculate total length:- Length of 70Ø...
  • Page 40 Fig. E Fig. F...
  • Page 41 Fig. G page 29 16. For aesthetic purposes it is permissible to route the 70Ø exhaust in an enclosed box, but the air inlet and plume outlet MUST remain in free air. 17. It is also possible to separate the plume outlet from the 93° elbow to allow the flue to be installed as shown in Fig.

  • Page 42: Installation

    Fig. J page 30 10.0 Installation Check Site Requirements (section 7) before commencing. 10.1 Initial Preparation The gas supply, gas type and pressure must be checked for suitability before connection (see Section 7.4). 1. Cut the banding and remove the fixing template, wall plate and literature pack (Fig.
  • Page 43 Fig. 20 Fig. 21 Fig. 22 page 31 10.2 Preparing The Boiler 1. Remove the outer carton and packaging. 2. Lift the outercase upwards and remove. 3. Remove the internal packaging.
  • Page 44 Fig. 22a Fig. 23 page 32 10.3 Fitting The Boiler (Fig. 1. Obtain retaining bracket and two M6 nuts from fitting bag. 2. Offer up the boiler to the wall plate using the lifting points shown in Fig. 24 and locate the rear bottom edge onto the self locating support at the base of the wall plate.
  • Page 45 3. Rotate the boiler up to wall plate and engage retaining bracket, securing with the two nuts. 4. Ensure the boiler is secured with the retaining bracket. 5. Remove red pipe protection caps from the FLOW and RETURN connections. Fig. 24 10.4 Making the Water Connections (Fig.
  • Page 46 Fig. 25 & Fig. 25a page 33 10.6 Making the Gas Connection 1. Connect the gas supply to the G in BSPT Internal) gas tap. This is located on the lower right side of the boiler, access by hinging down the PCB housing (see Fig.
  • Page 47 This dimension to be known as (Z). i.e. (Z) = wall plate to wall + wall thickness + 250 5. Take the flue and mark off (Z) from the terminal end as indicated (Fig. 27). Check your dimensions. The flue tubes are fixed together. Cut through both tubes whilst resting the flue on the semi-circular packing pieces. Deburr both tube ends. IMPORTANT: Check all measurements before cutting.
  • Page 48 Fig. 27a page 34 6. Ensure the inner flue support bracket is positioned in the flue (Fig. 28). 7. Engage the flue into the flue elbow using soap solution to ease the engagement ensuring the flue is assembled as shown (Fig.
  • Page 49 Fig. 29 & Fig. 29a Fig. 30 page 35 10.8 Making The Electrical Connections WARNING: This appliance must be earthed 1. The electrical connections are on the right hand side of the unit. 2. Undo the two screws securing the cable clamp and place to one side (Fig.
  • Page 50 3. The Main 30 Heat is factory set to give a maximum output of 22.0 kW. The Control PCB jumper positions are as follows: CN11 (Blue) CN12 (Red) If the installation requires a greater output to achieve the desired room temperature, this can be increased to 30.18 kW and the boiler can be adjusted as follows (Fig.
  • Page 51 Fig. 31, Fig. 32 & Fig. 33...

  • Page 52: Electrical

    page 36 11.0 Electrical 11.1 Schematic Wiring Diagram Key To Wiring Colours b - Blue - Red bk - Black g - Green w - White g/ y- Green/Yellow br - Brown op - Opaque gy - Grey - Yellow page 37 11.2 Illustrated Wiring Diagram...

  • Page 53: Commissioning The Boiler

    Wiring Key - Blue bk - Black br - Brown - Red - White g/y - Green/Yellow - Green gy - Grey op - Opaque - Yellow page 38 12.0 Commissioning the Boiler 12.1 Commissioning the Boiler WARNING: The PCB Control and Fan Assembly are 325 Vdc. Isolate at supply before access. 1.
  • Page 54 Water Central Heating Systems (see Section 6.2). 5. Complete the label supplied with the inhibitor and attach to the inside of the boiler case. Detail of system treatment should be added for future reference. 6. Turn the gas supply on and purge according to in GB BS 6891 and in IE I.S. 813 "Domestic Gas Installations"​ . 7.
  • Page 55 Fig. 35 & Fig. 36 page 39 12.2 Checking the Combustion 1. Follow the flow chart opposite.

  • Page 57: Fitting The Outer Case

    page 40 12.3 Check the Operational (Working) Gas Inlet Pressure 1. Ensure that all controls are calling for heat and maximum load is applied to the system. 2. With the boiler operating in the maximum rate condition check that the operational (working) gas pressure at the inlet gas pressure test point is in accordance with B.S.

  • Page 58: Servicing The Boiler

    Fig. 37 Fig. 38 page 42 14.0 Servicing the Boiler 14.1 Annual Servicing 1. For reasons of safety and economy, it is recommended that the boiler is serviced annually. Servicing must be performed by a competent person in accordance with B.S. 7967-4. 2.
  • Page 59 The integrity of the complete flue system and the flue seals. The integrity of the boiler combustion circuit and relevant seals as described in Section 14.2. The operational gas inlet pressure as described in Section 12.3.1 to 12.3.3 and the gas rate as described in 12.3.4. The combustion performance as described in 'Check the Combustion Performance' (14.1.4 to 14.1.6 below).
  • Page 60 Fig. 39 Fig. 40 & Fig. 41 page 44 11. To clean the heat exchanger and burner proceed as follows: a. Disconnect the electrical leads to the fan component protection sensor (Fig. 42). b. Loosen the screw retaining the gas injector pipe at the venturi (Fig.
  • Page 61 m. Reassemble in reverse order and check for leaks. 12. Check the CO/CO ratio and CO level at the flue sampling point (Fig.41a) is as quoted in Section 4.0, 'Technical Data'. 13. If the ratio or level is greater than that quoted telephone the Technical Enquiries for further advice. IMPORTANT: No adjustment of the gas valve is permissible.

  • Page 62: Changing Components

    Fig. 44 page 45 15.0 Changing Components 15.1 Changing Components IMPORTANT: When changing components ensure that both the gas and electrical supplies to the boiler are isolated before any work is started. "The boiler cannot be switched off at the boiler, therefore it is important to isolate the electrical supply at the mains fuse."​ Hazardous materials are not used in the construction of these products, however reasonable care during service is recommended.
  • Page 63 Fig. 45 Fig. 46...
  • Page 64 The thermistor, safety thermostat, interface PCB and the flow switch can be accessed after removal of the outer case. 15.2 Flow Temperature Thermistor and Safety Thermostat (Fig. 1. The procedure is the same for both the thermistor and the safety thermostat. 2.
  • Page 65 Fig. 49 & Fig. 48 page 47 The fan and venturi, gas valve, injector pipe, condensate trap, fan protection sensor, spark and sensing electrodes can be accessed and changed on the removal of the airbox door panel. 1. Remove the airbox door panel by loosening the four 1/4 turn screws (Fig.
  • Page 67 Fig. 50, Fig. 51 & Fig. 52 page 48 The removal of the fan is necessary to enable the changing of the injector pipe, condensate trap and gas valve (see section 15.6). 15.7 Injector Pipe (Fig. 1. Remove the injector pipe by pulling out from the 'O' ring joint in the gas valve. 2.
  • Page 68 Fig. 54 15.9 Condensate Trap (Fig. 1. Disconnect the condensate trap from the base of the heat exchanger. 2. Disconnect the condensate drain (outside the boiler) from the condensate trap. 3. Undo the condensate trap lock nut and remove the trap from the boiler. Disconnect the sensor leads. 4.
  • Page 69 Fig. 55, Fig. 56 & Fig. 57 Fig. 58...
  • Page 70 Fig. 59 15.11 Heat Exchanger 1. Drain the boiler (see section 15.1 paragraph 2 & 3). 2. Remove all components in the base of the airbox. 3. Undo the screws on the support bracket. Remove the screws securing the flow switch and return connections and remove the connections (Fig.

  • Page 71: Short Parts List

    Fig. 60 page 51 16.0 Short Parts List Short Parts List G.C. Manufacturers Description Part No. E06 058 Flow Temperature Thermistor (Red) 240670 E06 059 Flow Switch 242459 E58 912 Safety Thermostat (Black) 242235 H46 830 PCB 5121025 5109925 H13 184 Gas Valve 241900 E06 085 Viewing Window 242484...
  • Page 72 page 52...

  • Page 73: Fault Finding

    17.0 Fault Finding NOTE: The fan is supplied with 325 Vdc. Fan Fault Finding should only be carried out after the boiler has been electrically isolated. General Fault Finding should only be carried out by someone who is appropriately qualified. page 53 ELECTRICAL SUPPLY...
  • Page 74 page 54...
  • Page 75 DRY-FIRE...
  • Page 76 page 55 IGNITION LOCKOUT...
  • Page 77 page 56 OVERHEAT LOCKOUT...
  • Page 78 page 57 FAN LOCKOUT NOTE: The fan is supplied with 325 Vdc.
  • Page 79 Fan Fault Finding should only be carried out after the boiler has been electrically isolated. THERMISTOR page 58 page 59 page 60 page 61 GAS BOILER SYSTEM COMMISSIONING CHECKLIST This Commissioning Checklist is to be completed in full by the competent person who commissioned the boiler as a means of demonstrating compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.
  • Page 80 warranty. This does not affect the customer's statutory rights. page 62...
  • Page 81 SERVICE RECORD It is recommended that your heating system is serviced regularly and that the appropriate Service Interval Record is completed. Service Provider Before completing the appropriate Service Record below, please ensure you have carried out the service as described in the manufacturer's instructions.
  • Page 82 page 63...
  • Page 83 Baxi Customer Support 0344 871 1525 Opening hours Monday - Friday, 8.00am-6.00pm Weekends and Bank Holidays, 8.30am-2.00pm Please note calls may be recorded for training and monitoring purposes baxi.co.uk Register now to activate your warranty: www.baxi.co.uk/registration For the warranty to be maintained, please make sure... 1.

This manual is also suitable for:

Main heat 15Main heat 18Main heat 24Main heat 30

Table of Contents