Worcester 24cdi Installation Manual
View and Download Worcester 24CDi BF installation and servicing instructions online. WALL MOUNTED COMBINATION BOILER FOR CENTRAL HEATING AND MAINS FED DOMESTIC HOT. View and Download Worcester 24CDi BF installation and servicing instructions online. WALL MOUNTED COMBINATION BOILER FOR CENTRAL HEATING AND MAINS FED DOMESTIC HOT.
. Bosch Group 24CDi BF WALL MOUNTED COMBINATION BOILER FOR CENTRAL HEATING AND MAINS FED DOMESTIC HOT WATER INSTALLATION AND SERVICING INSTRUCTIONS GC NUMBER 47 311 29 BOILER OUTPUT Automatic Modulating Control To Domestic Hot Water and Central Heating Minimum 9.0 kW Maximum 24.0 kW. The advice and instructions given in this document covers, 2.6 Flue as far as possible, the foreseeable situations which may arise. The appliance has a room-sealed balanced flue system to the Contact Worcester Heat Systems Technical Department, Telephone: rear. 0990 266241, for advice on specific installations. 12.Pressure relief property.
Flow balancing using ‘Ball-o-Fix’ type valves is valve. Recommended to avoid an excessive reduction in flow to 13.Sealed system individual outlets. For further information contact Worcester expansion Heat Systems Technical Helpline. 2.10 Safety Considerations The appliance must not be operated in a waterless condition.
Technical Data Table 1. NOMINAL BOILER RATINGS (10 Minutes After Lighting) BOILER ADJUSTED FOR G20 (Natural Gas) BURNER SETTING OUTPUT INPUT (Net) GAS RATE PRESSURE Btu/h Btu/h m bar. 30,700 10.4 35,500 37.28 24.0 81,900 27.0 92,400 13.2 100.0 Note: Gross Heat Input x 0.901= Net Heat Input. Table 5 PERFORMANCE SPECIFICATIONS PRIMARY WATER CAPACITY 2.0 litres MAXIMUM MAINS INLET PRESSURE 10 bar MINIMUM MAINS INLET PRESSURE (working) for max.
Hot water flow 1.2 bar MINIMUM MAINS INLET PRESSURE (working) to operate appliance 0.7 bar MAXIMUM CENTRAL HEATING FLOW TEMPERATURE 82°C nom MAXIMUM CENTRAL HEATING SYSTEM SET PRESSURE 1.5 bar. Siting The Appliance Fig. Appliance casing dimensions and required clearances.
4.1 The appliance must not be installed in any room containing a bath or shower or in a bedroom or bed-sitting room. Particular attention is drawn to the requirements of the 100mm current I.E.E. Siting The Flue Terminal 6.
Air Supply See Fig. 4 6.1 Installations in cupboards or compartments require permanent vents for cooling purposes, one at high level and one 5.1 The flue must be installed as specified in BS 5440:Part 1and at low level, either direct to outside air or to a room. 7.10 Connections to the mains water supply must not be made 7.
Sealed Primary Systems without the authority of the local Water Company. 7.11 The pump is set at maximum and must not be adjusted. 7.12 Connections in the system must resist a pressure of upto See Figs. An Rc1/2 connection is bath water. Alternatively the shower must be fitted with an anti- provided. A mini expansion vessel kit is available from Worcester syphonage device at the point of the flexible hose connections.
Internal fuses F1 - 2A, F2 - 1.25A (20mm). Spare internal fuses appliance. Refer to Worcester Heat Systems Technical are supplied with the appliance. Refer to Fig 14.
Department for more information - Tel: 0990 266241. Functional flow diagram. Outputs Inputs DHW control knob Electronics/ CH Control knob microprocessor (Safety Low Voltage) CH pressure adjust pot Gas valve mode switch Reset button Convert AC to low voltage electronics Pump Electronics. Fig 11 - Electrical Connections Fig 13 - Mains Voltage External Controls Connections Ns Ls L Ns Ls L R Spare R Spare Remove Link Motor Ns Ls L Spare 1. ST12-Mains 9.
Cable Entry Clamp 3. Separate the air and flue ducts from the terminal. Installation Measure the distance from the inside edge of the mounting plate to the outside of the wall W. Fit the air ducts together and adjust the total length until it NOTE: READ THIS SECTION FULLY BEFORE COMMENCING corresponds with the W dimension. From the outside, make good the gap between the air duct and If a facia mounted programmer is to be fitted follow instructions the brickwork. Fit the flue terminal to the air duct and mark the with the programmer.
Position of the four fixing holes. Drill four holes 5mm (0.19in.) Hinge down the facia as described in Section 15.3, c. the indicating pointer giving a permanent record of the set system 13. Commissioning pressure. If the pressure indicated on the pressure gauge is greater than 2.6 bar when operating at the maximum central heating temperature, 13.1 SUMMARY The appliance is dispatched with the controls set to provide a an extra expansion vessel must be fitted to the system as close as maximum output for domestic hot water and central heating of possible to the appliance central heating return connection. NOTE: The burner pressure is factory set and if (after checking that the supply pressure is sufficient) the correct pressure is not Set the Programmer, if fitted, to HEATING & WATER. Obtained then Worcester Heat Systems Service Department should Set the operating switch to ON.
Be contacted. Close the tap and the burner will go off.
The appliance will then 14.4 Tell the user of the importance of regular servicing. Return to the central heating mode and automatically balance Worcester Heat Systems Ltd. Offer a comprehensive maintenance with the system requirements. remove the two wing nuts securing the combustion chamber.
Inspection And Servicing Unhook the securing rods out of the locating holes in the combustion chamber sides. Ease the combustion chamber front and side assembly clear of the appliance. Refer to Fig. 15.1 SERVICING (g) Burner Assembly.
reverse order using new gaskets/'O' rings/sealant where necessary. Always check that any electrical connections are Fig. Burner and Electrode correctly made and that all screws are tight.
16.4 COMPONENT REPLACEMENT 1. Automatic Air Vent. Flame sensor Remove the inner casing cover as described in Section 15.3 (b). Detail Drain the central heating circuit as described in Section 16.3 (a). Open the valves and fill and re-pressurise the system as Hinge down the facia panel into the servicing position as described in Section 13.2. Described in Section 15.3, c. Remove the air pressure switch bracket as described in 4.
Combustion Chamber Insulation. Refer to Fig. Expansion Vessel. Refer to Figs.
Valve taking care not to distort the pipework. Drain the central heating circuit as described in Section 16.3, a. Fit the replacement valve in reverse order.
Reconnect the Hinge the facia panel into the servicing position as described in discharge pipe. Water Diverting Valve. Refer to Figs. Circulating pump Check that the electricity supply to the appliance is turned off.
Drain the central heating and domestic hot water circuits as described in Sections 16.3, a and b. Hinge down the facia panel into the Servicing Position as Unscrew union fittings described in Section 15.3, c. Inlet Water Filter.
Refer to Fig. Domestic Hot Water Flow Restrictor. Check that the electric supply to the appliance is turned off. Remove the water to water heat exchanger assembly as Drain the central heating and domestic circuits as described in described in Section 15.4.18. Control Board.
Refer to Fig. Refer to Fig. Check that the electricity supply to the appliance is turned off. Check that the electricity supply to the appliance is turned off.
Remove the three screws fixing the facia bottom panel to the Remove the control board as described in Section 16.4, 23. 7 716 192 205 0 299 356 ‘O’ Ring Pack 7 716 192 207 0 299 357 Fuse Pack 7 716 192 206 0 Acccessories For 24CDi BF G.C.No.
Part WHS Part No. E01 064 BF Standard Terminal 225mm- 420mm 7 716 191 007.
Operational Flow Diagrams Room CENTRAL HEATING FUNCTION thermostat and/or mains programmer (or link) On Electronic MAIN SWITCH Green Light facia programmer (if fitted) On ST13 link in CH control knob On Two minute CH light On. Minimum Modulate gas Pump On. OVERRUN FUNCTION Within four minutes of last hot water Run pump demand until primary drops to 80°C primary temperature above 80°C AUTOFROSTAT FUNCTION No demand Wait in normal and primary off state for temperature 30 minutes below 8°C Monitor Internal 5°C Return to Run pump for. 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. The electronic control system for this boiler incorporates four lights on the facia. These are used to show normal operating status. But as a secondary function, by flashing, they can also be used to help provide fault diagnostics. Is the facia on/off switch turned on? Turn switch on. `(Clockwise) Is there a 230V AC live supply across Check electrical Terminal ST12 pins L supply to boiler.
And N Replace control board Has fuse F1 blown? (Section 16.4.22) Replace fuse and investigate cause. Suggestions: Cable damage, connections to (or faults within) pump, external 230V controls, transformer or board. With CH control knob fully clockwise, does There is no heat Is there 230V AC the boiler ignite and demand. Check room across terminal ST8 appear to run thermostat or mains pins LR and N? Normally in central programmer (or link).
Heating mode? Red diode is Is there a link. Drop down the facia. Is the boiler in a very Is the gas valve mode Turn to normal cold environment (less switch in the normal position. Replace control board.
Boiler is running in (Section 16.4.22). “Autofrost stat” mode.
Note: A wet board See Section 18. Is the gas supply Rectify gas supply connected and at the problem. Correct pressure? Remove front panel.
Remove inner cover. Repair or replace Reset and restart the Reset and restart the Are the electrodes and spark electrode boiler. Can a flame be boiler. Is the multiway connector at board position ST16 pushed Push fully home. Fully home on to the board? Remove multiway connector from board position ST16.
Test Is there continuity Repair or replace resistance across from contacts 17 and harness. Contacts 17 and 18 18 to DHW sensor? (yellow wires). Inspect the small resistor that is Replace control board. Attached to the Replace control board.
(Section 16.4.23). Multiway connector.
(Section 15.4.20). Is it missing or loose or in poor condition? Replace mains harness. Light indication during fault not Control board is likely covered by to be wet or damaged above details. Bosch Group Worcester Heat Systems Limited, Cotswold Way, Warndon, Worcester WR4 9SW. Telephone: (01905) 754624.
Fax: (01905) 754619. Technical Helpline (0990) 266241. 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.
. 24CDi/28CDi/35CDi II WALL MOUNTED COMBINATION BOILER FOR CENTRAL HEATING AND MAINS FED DOMESTIC HOT WATER INSTALLATION AND SERVICING INSTRUCTIONS 24CDi 28CDi 35CDi II GC NUMBER (N.G) 47 311 30 47 311 34 47 311 58 GC NUMBER (L.P.G.) 47 311 31. (24/28CDi) or 27.5kW (35CDi II). The hot water flow rate is of safety, to ensure compliance with the law. Limited to a nominal 9 l/min (24CDi) or 10 l/min (28CDi) or 12 1.2 The manufacturers notes must not be taken, in any way, as l/min (35CDi II) at a maximum temperature rise of 40°C.
Extension flue lengths available are from 726mm up to 4000mm IMPORTANT: Where back-flow prevention devices, including (24CDi) or up to 3000mm (28CDi and 35CDi II). Water meters, are fitted the expansion of hot water into cold A vertical flue assembly kit is available. Note: Gross Heat Input x 0.901 (NG) or x 0.922 (propane) = Net Heat Input. Technical Data NOMINAL BOILER RATINGS BOILER ADJUSTED FOR BOILER ADJUSTED FOR (10 minutes after lighting) G31 (Propane) G20 (Natural Gas) 24CDi 28CDi 24CDi 28CDi 35CDi II 35CDi II MAX. OUTPUT (DHW) 24.0 28.0 35.3 24.0 28.0.The value is used in the UK Government Standard Assesment Proceedure (SAP) for the energy rating of dwellings.
The test data from which it has been calculated have been certified by the Gastec notified body. Table 6a (24CDi) DOMESTIC HOT WATER - TEMPERATURE RISE DISCHARGE RATE l/min TEMPERATURE RISE °C. Siting The Appliance Fig. Appliance casing dimensions and required clearances. 4.1 The appliance may be installed in any room although particular attention is drawn to the requirements of the current I.E.E. Wiring Regulations BS 7671 and, in Scotland, the electrical 30mm. provisions of the Building Regulations applicable in Scotland, 159mm.
The standard uncut flue kit length is 425 - 725mm. Extension 6.2 The appliance can be fitted in a cupboard or compartment kits for flues up to 4m (24CDi), 3m (28CDi and 35CDi II) are with no vents for cooling but the minimum clearances must be available. NG (G20) LPG (G31) must be maintained. 7.5 The 10 litre expansion vessel is charged to 0.5 bar and is 24CDi 1.13 suitable for a static head of 5 metres (17.5ft). The pressure can be 28CDi increased if the static head is greater than 5 metres (17.5ft). An Rc1/8” connection is 25mm (1in) above the top edge of the bath to prevent its immersion provided.
A mini expansion vessel kit is available from Worcester in bath water. Alternatively the shower must be fitted with an anti- Heat Systems Ltd.
On very rare occasions an external frost thermostat might 11. Electrical be considered where parts of the system are remote from the appliance. Refer to Worcester Heat Systems Technical Department for more information - Tel: 41. Mains supply: 230V 50Hz, 180watts.
External fuse 3A, 11.10. Functional flow diagram. Outputs Inputs DHW control knob Electronics/ CH Control knob microprocessor (Safety Low Voltage) CH pressure adjust pot Gas valve mode switch Reset button Convert AC to low voltage electronics 24CDi Electronics Pump Electronics 28CDi 35CDi II Electronics Pump Electronics. Fig 11 - Electrical Connections Fig 13 - Mains Voltage External Controls Connections Ns Ls L Ns Ls L R Spare R Spare Remove Link Motor Ns Ls L Spare 1. ST12-Mains 9.
Cable Entry Clamp 3. a vertical line. Extend horizontally the side flue line to 12. Installation intersect the vertical line to give the position of the side flue hole. NOTE: If the optional wall spacing frame is used then the Read this section fully before starting the Installation. 197mm dimension should be increased by 35mm (see 12.1 General. Flue Spigot Kit.
IMPORTANT Check the maximum flue length and if it is less than 1m total overall length then fit the restrictor ring as shown in Fig. 40mm 24CDi 75mm Horizontal flue up to 1m. 750mm up to a maximum of 4m. See table below.
Installation
Apply the plastic tape to the air duct in contact with the external EXTENSION MAXIMUM FLUE LENGTH mm brickwork. 35CDi II 24CDi 28CDi From inside push the assembly through the wall. Align the flue turret 1475 1475 1475 and push fully onto the spigot on the appliance. Terminal assembly for internal 90° and 45° bends are available.
A maximum of two bends may be used in addition to the first bend on the flue turret. Fitting of the flue. A 90° bend is equivalent to 750mm of straight duct. The first, vertical, section (equivalent to dimension X) is measured from between the gas cock and the gas valve, thus enabling the leak to be the top of the boiler casing. Cut the vertical section of the extension traced to either a visible joint or to the ‘O’ ring. Duct to 167mm less than the measured distance.
should be fitted as shown in Fig. Set the system pressure Insert the bayonet end of the filling key into the corresponding cutouts Release water from the system using the relief valve test knob (see Fig. In the filling loop housing and twist to lock the key in place. 27), until the system design pressure is obtained, up to a maximum of Turn the grey knob anti-clockwise to allow water ingress and fill until 1.5 bar. The burner pressure should be 14.8mbar Refit the cabinet front panel. (24CDi) or 15.5mbar (28CDi) or 13.5mbar (35CDi II ) for natural gas and If the appliance is being passed over to the user immediately, refer to 35.5mbar (24/28CDi) or 34.7mbar (35CDi II) for propane. Appliance components and fixings 15.
Inspection And Servicing (upper assembly). 15.1 SERVICING Flue gas sample To ensure continued efficient operation of the appliance it Sensing tubes Fan assembly point (Red to +) must be checked and serviced as necessary at regular fixing screws (3) intervals. Burner and Electrode 16. Replacement Of Parts (24/28CDi shown) 16.1 SAFETY Flame sensor Switch off the electricity and gas supplies before replacing any components. After the replacement of any components, check detail for gas soundness where relevant and carry out functional checks as described in Section 13 - Commissioning 16.2 COMPONENT ACCESS To replace components it is necessary to remove one or more. Slacken the two screws to remove the two retaining brackets and Fig. Air pressure switch.
Lift the heat exchanger from the casing. Take care that the rear insulation pad does not drop forwards onto the burner. Fit the replacement heat exchanger in the reverse order ensuring that both the “O”. 1.5mbar (24CDi) or 1.0mbar (28CDi) or 3.1 Fit the replacement electrode in the reverse order, checking that mbar (35CDi II) for natural gas or 5.4mbar (24CDi) or 3.8mbar the sense gap is 5 to 6mm. (28CDi) or 3.1mbar (35CDi II) for propane. Central Heating Sensor.
Refer to Fig. Expansion Vessel Remove the inner casing cover as described in Section 15.3, b.
Check that the electricity supply to the appliance is turned off. Strap Carefully pull off the two leads from the sensor.
Pull off the sensor and spring retaining clip from the pipe. Reassemble the water diverting valve and plastic manifold Regulator size: assembly to the appliance in the reverse order. Ensure all ‘O’ ring seals and fibre washers are renewed and 24CDi 9 l/min white replaced correctly and the ‘O’ rings are lubricated. Filling Loop. Refer to Fig. Connectors are not interchangeable and will only fit the termi- Check that the electricity supply to the appliance is turned off. Nals from which they were removed.
Drain the central heating circuit as described in Section 16.3, a. Reassemble the facia panel and facia bottom panel in the reverse Hinge down the facia panel into the servicing position as order.
Short Parts List Appliance G.C. Part Manufacturer’s Reference Part No. 24CDi 28CDi 35CDi E80-450 Gas Valve – Natural Gas Dungs BM 771 SL 040 8 716 102 673 0 E80-451 Gas Valve – Propane Dungs BM 771 SL 040.
Operational Flow Diagrams Room CENTRAL HEATING FUNCTION thermostat and/or mains programmer (or link) On Electronic MAIN SWITCH Green Light facia programmer (if fitted) On ST13 link in CH control knob On CH light On. Two minute mini- Fan ON High for 2 mum burner Modulate gas. OVERRUN FUNCTION If heat Run pump demand has until primary occurred in drops to last 30 80°C minutes Within four minutes of last hot water demand primary temperature Run pump for If heat above 80°C two seconds demand has Run fan If primary until primary temperature. 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. The electronic control system for this boiler incorporates four lights on the facia. These are used to show normal operating status.
But as a secondary function, by flashing, they can also be used to help provide fault diagnostics. Is the facia on/off switch turned on? Turn switch on. `(Clockwise) Is there a 230V AC live supply across Check electrical Terminal ST12 pins L supply to boiler.
And N Replace control board Has fuse F1 blown? (Section 16.4.23) Replace fuse and investigate cause. Suggestions: Cable damage, connections to (or faults within) pump, fan, external 230V controls, transformer or board. With CH control knob fully clockwise, does There is no heat Is there 230V AC the boiler ignite and demand. Check room across terminal ST8 appear to run thermostat or mains pins LR and N? Normally in central programmer (or link).
Heating mode? Red diode is Is there a link. Drop down the facia.
Is the boiler in a very Is the gas valve mode Turn to normal cold environment (less switch in the normal position. Replace control board. Boiler is running in (Section 16.4.23). “Autofrost stat” mode.
Note: A wet board See Section 18. Is the gas supply connected and at the Rectify gas supply correct inlet and problem.
Outlet pressures? Remove front panel. Remove inner cover. Repair or replace Reset and restart the Reset and restart the Are the electrodes and spark electrode boiler.
Is the multiway connector at board position ST16 pushed Push fully home. Fully home on to the board? Remove multiway connector from board position ST16.
Test Is there continuity resistance across Repair or replace from contacts 17 and harness. Contacts 17 and 18 18 to DHW sensor? (yellow wires). (L) track if DHW mode? Centre (L) track if CH mode? Repair or replace fan (Section 16.4.3) or cable. 28CDi and 35CDi II 24CDi,28CDi and 35CDi II Replace control board (Section 16.4.23).
Air pressure switch Repair or replace fan is shorting (Section 16.4.3) or Replace switch cable. Light indication during fault not Control board is likely covered by above to be wet or damaged details. Or malfunctioning.
Check for wet board or connections. Dry and re-use or replace control board.
(Section 16.4.13). Hot water sensor Hot water could be off or poorly temperature always fixed to pipe. Conversion Instructions GAS VALVE ONLY COMPONENTS SUPPLIED BY WORCESTER HEAT Allen key SYSTEMS SHOULD BE USED. ONLY COMPETENT PERSONNEL SHOULD ATTEMPT THE CONVERSION. CONVERSION FROM NATURAL GAS TO LPG SHOULD NOT BE CARRIED OUT ON APPLIANCES INSTALLED IN A ROOM OR INTERNAL SPACE BELOW GROUND LEVEL. This manual is to be used in conjunction with the variant part number of the bar code below: 24CDi 28CDi 35CDi II Worcester Heat Systems Limited (Bosch Group), Cotswold Way, Warndon, Worcester WR4 9SW.
Telephone: 24. Technical Helpline 41. 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.