Bosch Group 15SBi / 24SBi WALL MOUNTED BOILERS FOR CENTRAL HEATING and Indirect supply of domestic hot water INSTALLATION AND SERVICING INSTRUCTIONS 24SBi This appliance is for use with Natural Gas or LPG (Cat II 2H3P). 15SBi GC NUMBER 41 311 43 (N.G.) 24SBi GC NUMBER 41 311 44 (N.G.) 15SBi GC NUMBER 41 311 45 (L.P.G.) 24SBi GC NUMBER 41 311 46 (L.P.G.) APPLIANCE OUTPUTS Natural Gas LPG (Propane) 24SBi Minimum 15.0 kW Maximum 24.0 kW 15.0 kW 24.0 kW 15SBi Minimum 6.0 kW Maximum 15.0 kW 6.0 kW 15.
Contents 1. Installation Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2 3. Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4 4. Siting the Appliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6 5. Flue Terminal Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 7 6. Air Supply . . . . . . . . . . . . . .
2.7 System All dirt must be flushed from the system before connecting the appliance. Refer to Fig. 5,6 and 7. The system can be pre-piped and flushed before the appliance is fitted. The connections in the system must withstand a pressure of up to 3 bar. Radiator valves must conform to BS2767:10:1977. 2.8 Domestic Hot Water Single feed direct cylinders are not suitable and must not be used. A HW cylinder must be of the indirect coil type and suitable for working at a gauge pressure of, at least, 0.
3. Technical Data Table 1. The data plate is fixed to the inner casing cover. 15SBi Table 1. 24SBi NOMINAL BOILER RATINGS (10 Minutes After Lighting) BOILER ADJUSTED FOR G20 (Natural Gas) BURNER OUTPUT INPUT (Net) GAS RATE PRESSURE kW kW m bar. m3/h 6 6.93 1.6 0.73 10.8 12 6.4 1.27 15 16.65 12 1.76 NOMINAL BOILER RATINGS (10 Minutes After Lighting) BOILER ADJUSTED FOR G20 (Natural Gas) BURNER OUTPUT INPUT (Net) GAS RATE PRESSURE kW kW m bar. m3/h 15 17.5 4.5 1.85 19.5 22.1 8 2.34 24 27 12.5 2.
Table 5 PERFORMANCE SPECIFICATIONS PRIMARY WATER CAPACITY 2.0 litres MAXIMUM MAINS INLET PRESSURE 10 bar MAXIMUM CENTRAL HEATING FLOW TEMPERATURE 85°C (nom) MAXIMUM CENTRAL HEATING SYSTEM SET PRESSURE 2.5 bar MINIMUM CENTRAL HEATING SYSTEM SET PRESSURE 0.5 bar OUTPUT TO CENTRAL HEATING NATURAL GAS (G20) 15SBi 6.0 - 15.0kw 24SBi 15.0 - 24.0kw LPG - PROPANE (G31) 15SBi 6.0 - 15.0kw 24SBi 15.0 - 24.0kw NOx CLASSIFICATION FOR BOTH 15 & 24SBi Class 2 SEDBUK Rating 15SBi - Band D - 79.
Fig. 2. Appliance casing dimensions and required clearances. 4. Siting The Appliance The appliance may be installed in any room subject to the requirements of the current IEE regulations and, in Scotland, the relevant electrical provisions of the Building Regulations with respect to the installation of appliances in rooms containing baths or showers.
5. Flue terminal positions 6. Air Supply The flue system must be installed following the requirements of BS5440:1. The standard flue kit length is 425 - 725mm. Extension kits for flues up to 4m are available. The terminal must not cause an obstruction nor the combustion products a nuisance. If the terminal is within 1m of a plastic or painted gutter or within 500mm of painted eaves then an aluminium shield at least 750mm long should be fitted to the underside of the gutter or painted surface.
expansion vessel must be fitted as near to the appliance as possible in the return pipe. A filling loop is fitted to the appliance. Refer to Fig 8. The system and the appliance must be properly vented. Repeated venting loses water from the system and usually indicates that there is a leak. An adjustable by-pass is fitted to the appliance. Refer to Fig 9. The pump is set at maximum and must be adjusted to suit the system load 7. Sealed System 7.
Fig. 7. System layout if using twin zone valves (S) plan. LV RV For Details of the wiring requirements for the system controls, please refer to the SBi system wiring guide. INDIRECT CYLINDER LV RV APPLIANCE RV LV Radiator Valve - Flow RV Lockshield Valve - Return LV Heating Flow RV Fig. 8. Filling Loop. Heating Return LV CH Zone Valve Refer to fig.1.
9. Gas Supply Fig.11 . Mains electricity connections. The 24SBi appliance requires a maximum of 2.86m3/h of natural gas (G20) or 1.1m3/h of propane (G31). Refer to Table 1. The 15SBi appliance requires a maximum of 1.76m3/h of natural gas (G20) or 0.68m3/h of propane (G31). Refer to Table 1. A natural gas appliance must be connected to a governed meter. The installation of the gas supply to the appliance must be in accordance with BS6891.
Fig.13 . Wiring diagram - pictorial.
Live Pin L X1 Fuse F1 4A Fast 12 Pump N X5 101 RY Top Pin Electronics Electronics Pin 1 X12 Left Terminal X2 2 RY N Fan 102 RY X4 Top Pin Top Pin X5 Hot water ON OFF Central Heating ON X12 Pin 5 X12 Pin 4 X12 Pin 3 X2 N Right Terminal Frost Thermostat (if fitted) Operating Switch or Programmer Power ON - Green Pin 2 X3 Call X3 Pump Fan Spark Valve Pin 4 Gas Pin 3 X3 C Satisfied X3 Pin 1 DC Pin 1 X10 Pin 2 X10 Cylinder Thermostat X10 Pin 3 Pr
Cut the flue duct hole at 110mm diameter [150mm diameter for internally fitted flues]. 11.4 Wall Mounting Plate and Manifold Fit the plugs and fix the mounting plate and manifold assembly to the wall. Refer to Fig 15. 11.5 Gas and Water Pipes Fix the appropriate fitting to the gas cock to connect the inlet supply pipe. Refer Fig 16. It is important that the system pipes are not fixed near the appliance using clips that put a strain on the connections.
Fig. 17 . Fixing the appliance to the wall mounting plate. Step. 2 Secure the top with M6 nuts and washers (2). Keep Appliance Vertical Appliance Step. 1 Rest the appliance on the pre-plumbing manifold and push backwards engaging the valves. Step.3 Secure the bottom with the caps and washers (3). Check that all the O-Rings are in place. Pre-plumbing manifold Lift the appliance against the wall to engage in the top support plate and lower onto the manifold assembly. Refer to Fig. 17.
Fig.20. Mid-position diverter valve (Optional) IMPORTANT 5 DO NOT REMOVE THIS CLIP! 1 1. 2. 3. 4. 5. 6. 7. Flow manifold assembly Clips (Removable) Diverter valve connector plug Earth connection Mid-position diverter valve Valve status indicator Manual operating switch 4 2 6 3 between 425mm and 725mm. Fix the flue assembly together using the self-tapping screws provided. Refer to Fig.22.
Fig.23 . Extension Duct. L Turret assembly Fixing screws Fixing screw Terminal assembly Ducts of equal length Appliance casing Shorten first extension fitted to the turret assembly if more than one extension is fitted Fig.25 . Rear flue. Fig.24. Flue duct length (side flue).
Fig.26 . Flue Turret Fixing . Fig.27 . Terminal assembly for internal fitting of the flue. 1 5 1 2 4 3 2 3 4 1. Flue centering ring 2. Air duct 3. Flue duct 1. Flue turret assembly 2. Clamp 3. Appliance 4. Fixing screw 4. Rubber sealing gasket 5. Flue Terminal Rubber sealing gasket Replace the inner casing. Flue terminal 11.11 Flue Bends. 90° and 45° bends are available. A maximum of two bends may be used in addition to the first bend on the flue turret.
Fig. 29 - Elbow to Flue Turret Assembly. Fig. 31 - Facia Connections Cover. 120mm 1 2 100mm Flue Turret Bend 3 1. Control Panel Fixing Screws 2. Facia 3. Control Panel Pivot Point 4. Connection Cover 5. Connection Cover Fixing Screws Fig.30 Vertical Adapter. Flue Duct 5 4 Air Duct Fig.32. Rear Connections Cover 1 Adapter 2 3 Flue Spigot 1. Rear Connections Cover Fixing Screws (2) 2. Rear Connections Cover 3. Cable Entry With Clamps 5 4 Facia 11.12 Vertical Adapter for Horizontal Flues.
Fig 34 - Programmer Connection - Facia Position 4 1. Programmer 2. Programmer Fixing Clip 3. Pressure Gauge 3 1 4. Programmer Connector 2 Fig. 36. Pump venting. 12. Commissioning The Appliance 1 12.1 Lift off the cabinet front panel. . Check that the electricity and gas supplies to the appliance are turned off and that all the water connections throughout the system are tight. Open the system valves at the appliance. Refer to Fig 16. Open all the radiator valves. Remove the automatic air vent cap.
an extra expansion vessel must be fitted to the system as close as possible to the appliance in the central heating return connection. The appliance [as despatched] can accommodate a system volume of about 90 litres. Refer to BS7074 Part 1, BS5449 and Table 9. If the system volume is greater then an extra vessel must be fitted as close as possible to the appliance in the central heating return connection and pressurised to the same figure as the integral vessel. 12.
Inner Casing. Unscrew the four screws and remove. Refer to Fig 18. 13. Instructions To The User Combustion Chamber. Unscrew the two screws at the top. Loosen but do not remove the two wing-nut extended screws at the sides, unhook the clips and remove the chamber. Refer to Fig 41 and 42. Fan. Carefully pull off the electrical connections and the tubes from the air flow detector. Unscrew the three screws to remove the fan assembly. Refer to Fig 51. Fig.40 . User controls.
Fig. 41. Inner Casing 15SBi 15 1 14 2 3 4 16 5 13 6 12 7 11 10 8 9 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
Fig. 42. Inner Casing 24SBi 14 1 13 2 3 4 5 12 6 11 7 10 8 9 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.
Fig.43 . Lower Casing - Gas and Water Controls. 5 1 4 6 2 3 1. 2. 3. 4. 5. 6. 7. 8. 1 15.4.1 Gas Valve Do not remove the inner casing. Unscrew the fixing screw and unplug the connections. Remove the air pressure switch. refer to section 15.4.19. Unscrew the union connections above and below the gas valve, unscrew the mounting bracket and remove the assembly. Use new gaskets when replacing the valve. Refer to Fig. 43.
15.4.5 Combustion Chamber Insulation Remove the burner and the primary heat exchanger. Refer to Section 15.3.4, 15.4.21. Replace the side and front pads in the combustion chamber assembly. Replace the rear insulation pad. Refer to Fig.45 Fig.46. Pressure Gauge Fixing. Fig.45. Combustion Chamber Insulation. 2 1 2 1 2 1. Pressure Gauge Head 2. Pressure Gauge Head Fixing Clips 3 1. Combustion Chamber Insulation - Front Panel 2. Combustion Chamber Insulation - Side Panel 3.
Fig.48. Rear Control Board Cover. 3 2 4 1 1. 2. 3. 4. 5. 6. 7. Control Board Cover Fixing Screws (4) Rear Connections Cover Fixing Screws (2) Rear Connections Cover Control Board Cover Facia Pressure gauge clock clips 5 7 6 15.4.9 Control Board Remove the facia bottom panel and carefully disconnect all the electrical connections. Refer to Fig. 11 and 12. Lower the facia panel and remove the splash cover. Refer to Section 14.3. Disconnect the earth connection at the appliance. Refer to Fig. 33.
15.4.15 Air Flow Detector Remove the fan as described in 15.3.13. Unscrew and withdraw, through the fan outlet, the air flow detector. Refer to Fig .51. The detector is 'handed' - do not force it into place. Fig.51. Fan /Flue Hood Assembly 5 4 2 1 6 15.4.16 Primary Flow Sensor Carefully pull-off the connections. Pull off the clip and remove the sensor. Refer to Fig .49. 15.4.17 Overheat Thermostat Carefully pull-off the connections. Twist the sensor to expose the fixing screws. Refer to Fig.49.
16. Short Parts List Key No. G.C. No.
I AUTO O M T W RUN DHW CH Th F S Su 8: 3 7 P DAY HR MIN Set R 29 ADV
DHW & CH selected on timer, tank stat calling, room stat calling. DHW & CH demand In addition for Y plan: DHW selected on timer & tank satisfied or DHW off signal from timer. CH = Central Heating DHW = Domestic Hot Water Facia light ON CH selected on timer & room calling.
18. Fault Finding NOTE: This fault finding information is for guidance only. Worcester Heat systems cannot be held responsible for costs incurred by persons not deemed to be competent. To use this guide, operate the boiler and follow the observations down the left hand column until the boiler fails. The associated tests will help find the fault. This guide assumes a component failure has occured following a period of normal runing. It is not intended to solve installation errors.
BOILER DEMAND TEST Set the system to create a boiler demand. Turn facia control knob to maximum. Does the boiler pump run? (removal of pump venter plug may help identify rotation of pump) No Is the facia indicator still on? No Refer to above section Yes Does the fan run and normal ignition take place? Yes No Drop down the facia and expose the three PCB rear connectors. Is there 230V at pins 3 & 4 of connector X11? (centre connector) No The system is not creating a boiler demand.
Does the electrode spark at the burner? No Does the fan stop after a few seconds? No No Remove electrical connectors from the pressure switch and restart the boiler. Is there continuity across the two switch terminals when the fan runs? No Pressure switch has not closed. Are the silicone tubes in good condition and free of condensation? Replace tubes. If condensation has occurred also replace pressure switch and check condition of venturi in the fan. Yes Inspect the flue.
Yes Are the spark electrodes and gap connections in good order? No Repair or replace electrodes or leads. Yes Replace control board. (Section 15.4.9) No Does the burner ignite? (use spy glass to observe flame) No (LOCKOUT will occur after 8 seconds) Is gas supply connected and at the correct pressure? Rectify gas supply problem. Yes Press facia button to reset the LOCKOUT.
Set the system to end the boiler demand. Does the burner shut down? No Yes Does the pump continue to run for approx 3 minutes? (failure to do so may cause overheat problems). Drop down the facia and expose the three PCB rear connections. Measure AC voltage at pins 3 & 4 of connection X11. This should be OV. No System is still creating a demand. Check appropriate “IMPORTANT NOTES” section of the wiring guide booklet.
This manual is to be used in conjunction with the variant part number of the bar code below: Bosch Group Worcester Heat Systems Limited, Cotswold Way, Warndon, Worcester WR4 9SW. Telephone: 01905 754624. Fax: 01905 754619. Technical Helpline 08705 266241. www.worcester-bosch.co.uk This booklet is accurate at the date of printing but will be superseded and should be disregarded if specifications and/or appearances are changed in the interests of continued improvement.
