Please leave these instructions with the user Baxi Combi 80 Maxflue Gas Fired Wall Mounted Combination Boiler Installation and Servicing Instructions
Natural Gas Baxi Combi 80 Maxflue G.C.No 47 075 07 Baxi UK Limited is one of the leading manufacturers of domestic heating products in the UK. Our first priority is to give a high quality service to our customers. Quality is designed into every Baxi product - products which fulfil the demands and needs of customers, offering choice, efficiency and reliability.
Contents Section Page 1.0 Introduction 4 2.0 General Layout 5 3.0 Appliance Operation 6 4.0 Technical Data 7 5.0 Dimensions and Fixings 8 6.0 System Details 9 7.0 Site Requirements 12 8.0 Installation 18 9.0 Commissioning the Boiler 23 10.0 Completion 25 11.0 Servicing the Boiler 26 12.0 Changing Components 28 13.0 Illustrated Wiring Diagram 37 14.0 Fault Finding 38 15.
1.0 Introduction Baxi UK Limited declare that no substances harmful to health are contained in the appliance or used during appliance manufacture. Case Front Panel 1.1 Description 1. The Baxi Combi 80 Maxflue is a fully automatic gas fired wall mounted combination boiler. It is room sealed and fan assisted, and will serve central heating and mains fed domestic hot water. 2. The boiler is set to give a maximum output of 24.0 kW for hot water and central heating. 3.
2.0 General Layout 2.1 Layout 1. Air Pressure Switch 2. Expansion Vessel 3. Burner Manifold 4. Automatic Air Vent 5. DHW Plate Heat Exchanger 6. Circulation Pump 7. Drain Off Point 8. Pressure Relief Valve 9. Position For Optional Integral Timer 10. Central Heating System Pressure Gauge 15 11. PCB 14 12. Control Box 13. 3-Way Valve Assembly 14. Flame Sensing Electrode 15. Spark Electrode 16. Burner 17. Primary Heat Exchanger 18. Fan Assembly 19.
3.0 Appliance Operation 1 Central Heating Circuit NOTE: All delay timers mentioned in 3.1 and 3.2 are overridden by domestic hot water demand. 3.1 2 3 4 7 26 5 6 25 24 23 9 27 21 11 17 10 16 19 15 14 13 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. 4.
4.0 Technical Data 4.1 Appliance Type C12 C32 C52 Appliance Category CAT II 2H 3+ Heat Input C/H & DHW (Gross) kW 26.3 Max Btu/h 89,739 Max Heat Output Max Min kW 24.0 9.3 Btu/h 81,891 31,730 Max Gas Rate (Natural Gas) (After 10 Mins) m3/h 2.78 ft3/h 98.12 Burner Pressure (Natural Gas) Max Rate Min Rate mbar 10.6 ± 0.5 1.9 ± 0.2 in wg 4.24 ± 0.2 0.76 ± 0.2 Inlet Pressure (Natural Gas) mbar 20 in wg 8 Burner Injector (Natural Gas) 15 x 1.
5.
6.0 System Details 6.1 Information 1. The Baxi Combi 80 Maxflue Combination Boiler is a ‘Water Bylaws Scheme - Approved Product’. To comply with the Water Bylaws your attention is drawn to the following installation requirements and notes (IRN). a) IRN 001 - See text of entry for installation requirements and notes. b) IRN 302 - Bylaw 14. 2. Reference to the WRC publications, ‘Water fittings and materials directory’ and ‘Water supply bylaws guide’ give full details of bylaws and the IRNs. 6.
6.0 System Details 6.5 System Filling and Pressurising 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 Double Check Valve DHW Mains Inlet Fig. 4 Stop Valve Temporary Hose 2. There are connection points on the mains cold water inlet and central heating return isolating taps (Fig. 4a) to which the optional filling loop kit (Part No.
6.0 System Details Other Tap Outlets 6.8 Expansion Vessel Boiler Stop Tap Fig. 6 1. All DHW circuits, connections, fittings, etc. should be fully in accordance with relevant standards, the Water Supply (water fittings) Regulations and the Water Bylaws (Scotland). 2. Your attention is drawn to: Schedule 2, Section 6 of the publication Water Regulations Guide which relates to backflow prevention. Check Valve Pressure Reducer Valve Domestic Hot Water Circuit (Fig. 6) To Hot Taps 3.
7.0 Site Requirements 450mm 5mm Min 5mm Min 7.1 5mm both sides recommended for ease of installation and service. 200mm Min 1. The installation must be carried out by a CORGI Registered Installer or other registered competent person and be in accordance with the relevant requirements of the current GAS SAFETY (Installation and Use) REGULATIONS, the BUILDING REGULATIONS (Scotland)(Consolidation), the LOCAL BUILDING REGULATIONS, the current I.E.E.
7.0 Site Requirements 7.5 Location 1. The boiler may be fitted to any suitable internal or external wall. It is primarily intended for use with a twin flue system using separate horizontal terminals. It may also be fitted with a vertical twin flue system connected to a single vertical terminal.
7.0 Site Requirements Air Terminal Appliance Position Input (kW) Above a Terminal Below a Terminal Horizontally to a Terminal Table 1 Separation in mm from another terminal Natural Draught Fanned Draught 0-7 7-14 14-32 over 32 300 600 1500 2000 300 300 300 300 0-7 7-14 14-32 over 32 300 300 300 600 300 300 300 300 0-7 7-14 14-32 over 32 300 400 600 600 300 300 300 300 7.8 Flue & Air Terminals 1. The flue terminal position must always be in accordance with the current edition of B.S.
7.0 Site Requirements Condensate Collector 7.9 90° Male - Male Elbow Flue Connections 1. The flue duct adaptor, air duct adaptor, 90° male - male elbow and condensate collector are supplied in a separate pack (Fig. 12). Also in the pack are two terminals and fixing screws for use with separate termination installations (see Section 7.13, Fig. 15). Flue Duct Adaptor Air Duct Adaptor 2.
Terminal 7.0 Site Requirements * 4 7.12 Flue Components 6 1,2,3 7 1,2,3 4 9 4 Terminal 1,2,3 * 1,2,3 1,2,3 5 4 5 5 Condensate Collector Condensate Collector 1,2,3 5 * 5 * 1,2,3 90° Male-Male Elbow 90° Male-Male Elbow 1,2,3 1,2,3 * * Flue and Air Duct Adaptors Flue and Air Duct Adaptors * * Items marked are supplied with each boiler in a separate pack marked Twin Flue Adaptor Kit (Maxflue) Part No 248338 * 16 No. Description 1. Straight Extension 0.25m Part No. 246135 2.
7.0 Site Requirements 7.13 L1 Flue Options 1. The Baxi Combi 80 Maxflue can be fitted with flue systems as illustrated (Figs. 15 & 16). L2 2. Maximum permissible equivalent flue lengths are:- L1 + L2 = 70m Max (L1 = 15m Max) Vertical Roof Terminal Separate Terminals 15m 70m IMPORTANT: When installing a flue system with separate terminals the air duct must not exceed 15m. 3.
Fixing Template 8.0 Installation 921.724.1 200 mm Minimum Clearance 107mm Dia Minimum Aperture For Flue Tube Horizontal Side Flue Centre Line 8.1 Initial Preparation The gas supply, gas type and pressure must be checked for suitability before connection (see Section 7.6). Vertical Flue Centre Line Appliance Wall Plate 1. After considering the site requirements (see Section 7.0) position the fixing template (Fig. 17) on the wall ensuring it is level both horizontally and vertically.
Wall Plate 8.0 Installation 8.4 Fitting The Boiler 1. Remove the sealing caps from the boiler connections. 2. Lift the boiler using the lower edges. Engage the slots at the top rear of the boiler on the wall plate (Fig. 19). 3. Insert the sealing washers between the valves and pipes on the wall plate and the boiler connections. The rubber washers must be used on the gas connections. 4. Tighten all the connections. 5.
8.0 Installation Blanking Pipe 8.6 Gasket Fitting The Flue 1. Sections 7.12 and 7.13 give details of available flue components, equivalent flue lengths etc. 2. The flue and air duct adaptors must be fitted to the boiler outlet adaptor and boiler top panel (Fig. 21). Boiler Outlet Adaptor Fig. 21 3. Pass the seal over the flue duct adaptor. Engage the 60mm diameter end of the flue duct adaptor on the boiler outlet adaptor and slide the seal down so that it equally covers the joint (Fig. 22). 4.
8.0 Installation 8.6 Fitting the Flue (Cont) Condensate Collector 10. The flue system can now be fitted. All burrs must be removed from any cut pipes to prevent damage to joint seals. Soap solution can be used to ease assembly of flue components. 90° Male - Male Elbow 11. The condensate collector must be fitted in the flue duct as shown and described in Section 7.11 (Fig. 24).
8.0 Installation 8.7 Making The Electrical Connections To connect the mains input cable proceed as follows:1. Slacken the facia securing screws and lift the outercase panel so that its securing tabs are clear of the facia. Remove the panel. Control Box Cover 2. Remove the screws securing the facia panel and hinge it down (Fig. 27). Fig. 28 3. Remove the control box cover securing screws. Disengage the barbs on the control box from the cover. Remove the cover (Fig. 28). 4.
9.0 Screw 9.1 Commissioning the Boiler Commissioning the Boiler 1. Reference should be made to BS 5449 when commissioning the boiler. Automatic Air Vent 2. Open the mains water supply to the boiler. 3. Open all hot water taps to purge the DHW system. 4. Ensure that the filling loop is connected and open, then open the heating flow and return valves on the boiler. 5. Open the screw on the automatic air vent (Fig. 32). Pump Fig. 32 6.
9.0 9.2 Commissioning the Boiler Checking the Burner Pressure 1. Turn on the gas and electrical supplies to the boiler and ensure that all external controls are calling for heat. 2. Set the hot water temperature control to maximum and the selector switch to the OFF position (Fig. 37). Pressure Test Point Screw 3. Slacken the pressure test point sealing screw and connect a pressure gauge. Disconnect the sensing pipe from the spigot adjacent to the pressure test point (Fig. 35). Fig. 35 4.
10.0 Completion Case Front Panel 10.1 Completion 1. Hinge the facia panel upwards and refit the case front panel. Secure them with the screws previously removed (Fig. 38). 2. Instruct the user in the operation of the boiler and system, explaining the operational sequence. 3. Carefully read and complete all sections of the “Benchmark” Installation, Commissioning and Service Record Log Book that are relevant to the appliance and installation.
11.0 Servicing the Boiler Case Front Panel 11 .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. 2. After servicing, complete the relevant section of the “Benchmark” Installation, Commissioning and Service Record Log Book. This should be in the possession of the user. 3. Ensure that the boiler is cool. 4. Ensure that both the gas and electrical supplies to the boiler are isolated. Fig. 39 5.
Baffle Tab Spring Clip 11.0 11.1 Servicing the Boiler Annual Servicing (Cont) 11. Remove the spring clips retaining the air box side baffle plates. Disengage the tabs on the baffles from the slots in the fan hood (Fig. 42). 12. Undo the screws securing the fan hood to the appliance back panel, and draw the fan and hood assembly forwards. Fig. 42 Fan and Hood Assembly 13. Draw the burner out of the combustion box, pulling the electrode grommets from the slots in the combustion box lower panel (Fig.
12.0 Changing Components IMPORTANT: When changing components ensure that both the gas and electrical supplies to the boiler are isolated before any work is started. When the new component has been fitted turn the selector switch fully anticlockwise against the spring pressure to position R and hold for 2 seconds to reset the boiler before recommissioning. Pressure Switch Sensing Tubes See Section 11.1 “Annual Servicing” for removal of case panel, door etc. Fig. 46 12.
12.0 Changing Components 12.3 Heat Exchanger (Fig. 49) 1. Note the positions of the two sensing tubes on the outlet elbow and three wires on the fan motor and remove them. 2. Slacken the screws on the outlet sealing collar. Ease the collar upwards as far as possible. Heat Exchanger 3. Remove the four screws securing the combustion box door and remove the door. 4. Remove the spring clips retaining the air box side baffle plates. Disengage the tabs on the baffles from the slots in the fan hood. 5.
12.0 Changing Components Injector Manifold Inlet Elbow 12.5 Injectors (Fig. 51) 1. Remove the burner as described in Section 12.4. Gasket Injector Burner Electrodes Fig. 51 2. Undo the screws securing the injector manifold to the inlet elbow and remove the manifold. 3. Unscrew and replace injectors as required and examine the sealing gasket, replacing as necessary. Reassemble in reverse order. 12.6 Electrodes (Fig. 51) 1.
12.0 Changing Components 12.8 Gas Valve (Fig. 53) 1. Undo the nut on the gas feed pipe under the boiler. 2. Disconnect the two wires from the valve modulator and the ignition lead from the NAC plug. Gas Valve 3. Disconnect the earth wire from the NAC plug and spade terminal on the gas valve body. NAC Plug 4. Undo the screw securing the NAC plug to the gas valve. Carefully pull the NAC forwards off the valve. 5.
12.0 Changing Components 12.12 Pump - Head Only (Fig. 56) 1. Drain the primary circuit and remove the socket head screws securing the pump head to the body and draw the head away. 2. Undo the screw on the pump wiring cover and remove the cover. Using a suitable flat bladed screw driver press the cable securing levers downwards to release each wire after noting their position. 3. A standard Grundfos replacement head can now be fitted. A Grundfos 15-50 head is suitable for the Combi 80e.
12.0 Changing Components 12.15 Pressure Gauge (Figs. 59 & 60) 1. Drain the primary circuit and undo the nut on the pressure gauge capillary. 2. Remove the timer cover and ease the timer wiring aside. Undo the screws securing the gauge retaining bracket. 3. Remove the bracket and gauge assembly. Depress the barbs on the side of the gauge and remove the retaining bracket. Fig. 59 Pressure Gauge Capillary 4. Reassemble in reverse order. Gauge Retaining Bracket 12.16 Expansion Vessel (Fig. 61) 1.
12.0 Changing Components 12.18 Pressure Relief Valve (Fig. 63) 1. Drain the primary circuit. 2. Disconnect the discharge pipe from the valve. Using a suitable hexagon key undo the grub screw sufficiently to release the valve. 3. Note the orientation of the valve, rotate it and withdraw it from the manifold. 4. Fit the new valve and ‘O’ ring seal and set to the previously noted orientation. Reassemble in reverse order. ‘O’ ring seal 12.19 P.C.B. (Fig. 65) 1.
12.0 Changing Components Plate Heat Exchanger 12.21 Plate Heat Exchanger (Fig. 66) 1. Drain the primary circuit. 2. While supporting the heat exchanger undo the screws securing it to the brass manifolds. 3. Withdraw the heat exchanger upwards and to the left of the gas valve, taking care not to damage any wires or controls. Rubber Seal Seals 4. There are four rubber seals between the manifolds and heat exchanger which may need replacement. Fig. 66 5. Ease the seals out of the manifold.
12.0 Changing Components 12.22 Diverter Valve Assembly (Cont) Pressure Differential Valve (Fig. 69) 1. Remove the DHW Flow Sensor as described above. 2. From the brass diverter manifold undo the nut on the heating flow valve. Remove the screw securing the diverter manifold to the appliance lower bracket. 3. Disconnect the pressure gauge capillary from the diverter manifold and remove the two wires from the Pressure Differential microswitch. 4.
13.
14.0 Fault Finding Carry out initial fault finding checks 1. Check that gas, water and electrical supplies are available at the boiler. Electrical supply = 230V - 50 Hz. CH water system pressurised to 0.5 bar when the boiler is cold. The preferred minimum gas pressure is 19.5mbar (natural gas), 27mbar (butane) or 36mbar (propane). 2. Carry out electrical system checks, i.e. Ground Continuity, Resistance to Ground, Short Circuit and Polarity with a suitable meter.
14.0 Fault Finding Domestic Hot Water - Follow operational sequence Turn selector to neon illuminated NO Replace diaphragm Go to section ‘A’ YES YES Is mains water filter and differential assembly clean? YES NO YES Turn thermostat to max. Open DHW tap fully. DHW flow switch operated NO DHW flow valve diaphragm damaged DHW flow rate more than 2.5l/min.
14.0 Fault Finding Fault Finding Solutions Sections A to E A Is there 230V at: 1. 2. 3. B Main terminals L and N Main terminal fuse NO Check electrical supply YES Selector terminals a & b and a & 3. PCB - A4 connector terminals 4 & 5 Replace fuse NO Check wiring Replace selector neon illuminated NO Is there 230V at: NO 1. Pump 2. PCB - A4 connector terminals 3 & 6 If pump jammed, release Replace pump NO Replace PCB YES Change pump supply cable C NO 1. CH system pressure 0.5 to 1.
14.0 Fault Finding E F Check and correct if necessary 1. Electrical and pressure tube connections 2. Blockage of pressure tubes 3. Restriction in flue 4. Venturi Gas at burner NO NO Replace air pressure switch Ensure gas is on and purged PCB - A1 connector has 230V AC across terminals 2 & 4 YES Replace gas valve NO neon flashing YES Turn selector switch to reset position R NO Replace PCB G 1. Check the burner setting pressure of the gas valve (see Section 9.2 of Commissioning) 2.
14.0 Fault Finding I Ensure that mains input terminal L is Live (230V) and N is Neutral (0V) YES Check and correct if necessary 1. Flame sensing electrode and lead connections 2. Electrode position YES Flame current should be 1 µA approx. J Overheat thermostat operated or faulty, i.e. continuity across thermostat terminals NO NO Replace PCB Replace flame sensing electrode Allow to cool. Continuity across thermostat terminals more than 1.
15.0 Short Parts List Short Parts List 22 44 135 131 140 291 63 154 23 Key No. G.C. No. Description Manufacturers Part No. 22 E66 383 Fan 248001 23 E66 385 Pressure Switch 248466 32 E66 393 Heat Exchanger 248016 41 E66 399 Burner 248030 44 E03 659 Injector 247439 59 E66 408 Electrode Lead 248467 63 E66 411 Spark or Sensing Electrode 247384 72 E66 431 Pump 248041 101 E66 434 3-Way Valve Assy.
Comp No 248465 - Iss 4 - 5/02 After Sales Service 08706 096 096 Technical Enquiries 08706 049 049 Baxi UK Limited Brownedge Road Bamber Bridge Preston Lancashire PR5 6SN www.baxi.com 921.731.
