Worcester 24I RSF, Installation And Servicing Instructions

Page 1: ...r Modulated Control Minimum 7 5 kW 25 600 Btu h Maximum 23 4 kW 80 000 Btu h To Central Heating Modulated Control Auto Range Rated Minimum 7 5 kW 25 600 Btu h Maximum 23 4 kW 80 000 Btu h THESE INSTRUCTIONS APPLY IN THE UK ONLY THESE INSTRUCTIONS ARE TO BE LEFT WITH THE USER OR AT THE GAS METER This appliance must be installed by a competent person in accordance with the Gas Safety Installation an...

Page 2: ...rd due to the appliance being electrically unsafe There are no substances used that are a potential hazard in relation to the COSHH Regulations 1988 1 7 The advice and instructions given in this document covers as far as possible the foreseeable situations which may arise Contact Worcester Heat Systems Technical Helpline for advice on specific installations 2 1 This appliance is not suitable for e...

Page 3: ...ons throughout a sealed system must be capable of sustaining a pressure of up to 3 bar Radiator valves must conform to the requirements of BS 2767 1991 The relief valve discharge must be directed away from any electrical components or where it would cause a hazard to the user A drain cock to BS 2879 must be fitted to the lowest point of the system For circuit design purposes it is important that d...

Page 4: ...VERALL HEIGHT including flue turret 960mm 37 8 inches CASING HEIGHT 800mm 31 5 inches CASING WIDTH 450mm 17 7 inches CASING DEPTH 360mm 14 2 inches WEIGHT including water 44 kg INSTALLATION WEIGHT 39 kg PACKAGED WEIGHT 44 kg PRIMARY WATER CAPACITY 3 0 litres MAXIMUM COLD SUPPLY PRESSURE 10 Bar 150 psi MINIMUM COLD SUPPLY PRESSURE working for max hot water flow 0 9 bar MINIMUM COLD SUPPLY PRESSURE ...

Page 5: ...5440 2 are strictly followed Notwithstanding the instructions given in BS 5440 2 this appliance may be fitted in a compartment with no vents as long as the minimum clearances stated in Section 6 Air Supply are maintained 4 7 The airing space must be separated from the boiler space by a perforated non combustible partition Expanded metal or rigid wire mesh are acceptable provided that the major dim...

Page 6: ... given in Section 4 Siting The Appliance then permanent vents for cooling are required One at high level and one at low level either direct to outside air or to a room Both vents must pass to the same room or be on the same wall to the outside air 6 4 The minimum free areas required are given below 6 5 Refer to BS 6798 and BS 5440 2 for additional information 6 Air Supply 5 Siting The Flue 6 L L K...

Page 7: ...nnection should be made in the central heating return as close to the appliance as possible 7 9 Repeated venting loses water from the system It is essential that this water is replaced and the system pressure maintained 7 10 Connections to the mains water supply must not be made without the authority of the local Water Company 7 11 The pump is set at maximum and must not be adjusted 7 12 Connectio...

Page 8: ...rmostatically controlled or pressure equalising shower valves will guard against the flow of water at too high a temperature 9 12 The head of a loose head shower must not fall closer than 25mm 1in above the top edge of the bath to prevent its immersion in bath water Alternatively the shower must be fitted with an anti syphonage device at the point of the flexible hose connections 9 13 The supply o...

Page 9: ...r kits 10 9 A time switch or programmer can be fitted externally to the appliance 10 10 The boiler provides automatic frost protection the use of a frost thermostat is not recommended However if an external frost thermostat is considered necessary then it must be used in conjunction with a programmer Important To provide external frost protection the appliance must have the Central Heating Tempera...

Page 10: ...ins 15 16 X6 Pins 5 6 7 X6 Pins 1 2 X6 Pins 19 20 X6 Pins 3 4 Flow signal CH temp sensor DHW temp sensor CH control POT Air pressure switch MAINS PROGRAMMER CLOCK FULL SEQUENCE CONTROLLER GAS VALVE LOW VOLTAGE ELECTRONICS Microcontroller ROOM STAT X1 X2 3 2 1 1 2 3 4 6 5 RL1 X3 Pin 1 X3 Pin 2 X4 Pin 3 X5 Pin 3 X5 Pin 2 X5 Pin 1 X4 Pin 1 FAN PUMP RL3 RL4 N N N N L ...

Page 11: ...e appliance is in accordance with the instructions given in Sections 4 and 5 Hold the template to the wall Check that the template is horizontal See Fig 10 Mark the position of the fixing holes and the position of the flue hole centre line onto the wall See Fig 10 Side Flue Extend the flue hole centre line from Fig 11 along the appropriate wall Check that it remains horizontal and mark a horizonta...

Page 12: ...ng that the cuts are square and free from burrs Always check the dimensions before cutting the ducts All extension duct dimensions refer to the straight lengths The socketed ends must not be removed or included in any measurement 11 4 EXTERNAL FITTING OF THE DUCT ASSEMBLY Measure distance L Side flue duct length L 184mm See Fig 14 Rear flue duct length L 181mm See Fig 13 Do not cut either the turr...

Page 13: ...th be reduced to the same length L 240mm where one extension is used L 990mm with two extensions and L 1 740mm with three See Fig 17 The flue can then be assembled ensuring that the cut extension is fitted to the turret duct assembly first and that the flue is adjusted to the correct length of L 184mm for side flues or L 181mm for rear flues See Fig 16 5 Finishing the flue Apply the plastic tape p...

Page 14: ...be cut to Y 162mm The swaged ends must be removed from the extension tube and only the air duct needs fixing See Fig 21 Z is the final flue length from the last elbow to the outside face of the external wall The first duct sections fitted to the elbow must have unswaged ends The length of the air ducts should be Z 196mm The inner flue duct must be 30mm longer than the air duct If Z 196mm is less t...

Page 15: ...ted in BS 6891 Refer to Section 12 for a full description of the filling venting and the pressurising of the system If the appliance is not to be commissioned immediately replace the cabinet front panel Check that the gas supply the electrical supply and the water connections are all turned off If the premises are to be left unoccupied during frosty conditions then drain the appliance and system F...

Page 16: ...creased if necessary Set the System Pressure Fill the system until the pressure gauge shows 2 5 bar 37 lb ins2 and check for water soundness Release water from the system using the relief valve test knob until the initial System Design Pressure is obtained up to a maximum of 1 5 bar Initial System Design Pressure bar Expansion Vessel Charge Pressure 0 3 bar Note 1 bar is equivalent to 10 2 metres ...

Page 17: ...rating procedure Check for proper ignition of the burner after a break in the gas supply Turn off the gas service cock and wait for 60 seconds The burner will go out but sparking from the electrode will continue for 10 seconds when the appliance will enter a lockout state Carefully open the gas service cock interrupt the mains power supply to the appliance for a few seconds to reset the controls a...

Page 18: ...clear See Section 6 Air Supply Check the system and remake any joints or fittings which show signs of leakage Refill vent and re pressurise as described in Section 12 2 Operate the appliance and the system taking note of any faults Measurement of the Flue Gases For consistency of results of the flue gas measurements it is necessary to have a constant output and for the appliance to be at equilibri...

Page 19: ... Fig 31 14 4 SERVICE OF COMPONENTS Clean the Fan Any dust or fluff should be removed with a soft brush or by blowing Take care not to distort the pressure sensing device Clean the Main Burner Brush the blade tops and mixing tube with a soft brush and check that all the flame ports are clear Remove any blockages with a non metallic brush Inspect the injector and clean with a soft brush Replace the ...

Page 20: ...l as described in Section 14 3 a and lower the facia Section 14 3 c Carefully pull off the sensing tubes and the electrical connections from the switch Remember to note their positions Unscrew the two screws behind the Air Pressure Switch and remove the switch from the appliance Fit the replacement switch in the reverse order ensuring that the electrical connections have been made to the correct t...

Page 21: ... check for soundness To set the burner pressure See Fig 33 The minimum and maximum burner pressures must be set after a new gas control has been fitted The maximum burner pressure must be set first as any adjustment of the maximum pressure influences the minimum pressure setting Start the appliance in the domestic hot water mode as described in section 12 4 Appliance Operation Adjust the maximum p...

Page 22: ...n the reverse order Open the valves and fill and re pressurise the system as described in Section 12 2 16 Pressure Relief Valve See Fig 35 Drain the central heating circuit as described in Section 15 3 a Hinge down the facia assembly as described in Section 14 3 c Remove the Bottom panel as described in Section 14 3 d Undo the discharge pipe connection and remove the valve retaining clip Remove th...

Page 23: ...es from natural gas to LPG and vice versa Only components supplied by Worcester Heat Systems should be used Only competent persons should attempt the conversion Conversion from Natural Gas to LPG should not be carried out on appliances installed in a room or inter nal space below ground level 1 Ensure the gas service cock is turned OFF and the elec trical supply is isolated 2 Refer to section 14 3...

Page 24: ...mbar for 60 seconds Burner pressure automatically adjusted for range rating and then modulated to maintain set flow temperature AUTOMATIC START UP SEQUENCE CENTRAL HEATING DEMAND SATISFIED Water flow temperature monitored by central heating sensor Pump on Operating Switch or programmer and room thermostat on CENTRAL HEATING DEMAND Internal Autofrostat demand Is fan in overrun mode Air pressure swi...

Page 25: ... End of hot water demand with no central heating demand Hot water thermistor above 40 C 6 second pump pulse with a 2nd 6 second pump pulse 2 minutes later End of demand or central heating temperature above 70 C monitored by the central heating sensor Fan on for 4 minutes Inhibit operations for approximately 1 second 6 second delay before re ignition from any other demand Is the central heating mod...

Page 26: ... X6 Pins 1 2 X6 Pins 19 20 X6 Pins 3 4 Flow signal CH temp sensor DHW temp sensor CH control POT Air pressure switch MAINS PROGRAMMER CLOCK FULL SEQUENCE CONTROLLER GAS VALVE LOW VOLTAGE ELECTRONICS Microcontroller ROOM STAT X1 X2 3 2 1 1 2 3 4 6 5 RL1 X3 Pin 1 X3 Pin 2 X4 Pin 3 X5 Pin 3 X5 Pin 2 X5 Pin 1 X4 Pin 1 FAN PUMP RL3 RL4 N N N N L 18 Fault Finding ...

Page 27: ...nsure link is fitted at X2 pins 5 6 Is mains LED flashing GO TO CHECK D GO TO CHECK K GO TO CHECK K GO TO CHECK E GO TO CHECK F GO TO CHECK O GO TO CHECK C Is control knob set for demand Is a room thermostat fitted Is room thermostat calling for heating Is programmer fitted Is programmer calling for heat Is pump running Has overheat thermostat tripped Is mains LED illuminated YES YES YES YES YES Y...

Page 28: ...ce thermistor Replace harness Short circuit Faulty PCB Replace Is resistance between pins 3 4 between 690ohms 33k Is resistance between pins 19 20 between 690ohms 33k Replace fuse Is mains present at X1 pins 1 3 GO TO CHECK H GO TO CHECK I GO TO CHECK H GO TO CHECK J NO NO NO YES YES YES YES YES YES NO NO OK OK OK OK Faulty Faulty Faulty Faulty NO ...

Page 29: ...re Connector Faulty pump Is pump connector secure on the PCB X3 Is fan connector secure on the PCB X4 Is mains present at the pump connector X3 pins 1 2 Is mains present at the fan connector X4 pins 1 2 ATTACH to heat exchanger Is capillary broken Ensure appliance is cool and retest Replace overheat thermostat Is capillary firmly ATTACHED to exchanger GO TO CHECK I GO TO CHECK O GO TO CHECK L YES ...

Page 30: ...ectors Is continuity observed between each end of wire in question Faulty harness or connector Harness OK Remove appropriate connectors Faulty harness Harness OK Is short circuit observed between pair of wires in question Is resistance between terminals of thermistor between 690ohms 33k Faulty thermistor YES YES YES YES NO NO YES YES NO ...

Page 31: ...re modulate Ignition OK Faulty PCB Replace Is flame sense electrode in flame Is lead secure both ends Secure lead Ensure flame sense electrode in flame at minimum burner pressure Are ignition leads connected both ends securely Does sparking occur Does ignition occur YES YES YES YES YES HARNESS OK YES YES YES YES YES NO NO NO NO NO NO NO NO NO NO GO TO CHECK G GO TO CHECK E GO TO CHECK M GO TO CHEC...

Page 32: ...present at input to gas valve Ensure gas supply Faulty board Replace Faulty gas valve Replace Is live output present at X5 pins 1 2 relative to neutral at pin 3 Is gas pressure present at input to burner Gas valve OK With fan running disconnect BROWN wire DO NOT touch chassis with it Is a short circuit observed across exposed APS terminals Gas Valve Check NO NO NO YES YES YES YES YES NO NO NO Air ...

Page 33: ...resistance nominally 125ohms Does voltage go above 6 25V Faulty PCB Replace Reconnect X6 and measure voltage across modulating valve during operation Gas valve OK Remove X6 Close all taps to set no domestic flow Faulty flow switch Replace Faulty flow switch Replace Is short circuit observed at X6 pins 1 2 Is open circuit observed at X6 pins 1 2 Open a tap fully to set domestic flow Flow Switch OK ...

Page 34: ...389mm Dia Winkelman Panhof 1 8 716 142 502 0 15 E01 604 PCB Boiler Control Pactrol 1 8 716 146 300 0 16 E04 582 Temperature Thermistors Elmwood 2 8 716 142 384 0 E01 900 CH Thermistor Clip 1 8 716 148 313 0 299 495 DHW Thermistor Clip 1 8 716 148 303 0 18 E01 605 DHW Flow Regulator 1 8 716 141 052 0 19 324 822 Gauze Filter WHS 1 8 716 148 401 0 20 299 363 Flow Sensor WHS 1 8 716 141 000 0 21 E01 6...

Page 35: ...35 9 8 14 3 21 1 15 13 4 22 11 7 12 10 23 20 6 25 24 2 19 18 16 23 ...

Page 36: ...anged in the interests of continued improvement All goods sold are subject to our official Conditions of Sale a copy of which may be obtained on application PUBLICATION 8 716 145 028C 11 98 Bosch Group Worcester Heat Systems Limited Cotswold Way Warndon Worcester WR4 9SW Telephone 01905 754624 Fax 01905 754619 Technical Helpline 0990 266241 ...