Service booklet for the Engineer for Gas Condensing Boilers 6 720 610 577-00.10 7 181 465 346 GB (03.
Table of contents Table of contents Warnings 3 Symbols 3 1 1.1 1.2 Layout of Appliance combi system 4 4 5 2 2.1 2.2 2.3 2.4 2.5 2.5.1 2.5.2 Bosch Heatronic board functions Initialisation Temperature display Indication of faults Special programme visualisation Boiler service functions First Service Level Secondary Service Level 6 6 6 6 6 8 8 11 3 3.1 3.2 3.2.1 3.2.2 3.3 3.4 3.4.1 3.4.
Warnings Warnings Repairs B Repairs may only be carried out by an approved installer! B Before carrying out any work on the appliance, switch it off at the master switch! B Even when the appliance is switched off at the master switch, some components on the PCB control board inside the control box are still live. Therefore: B Before carrying out any work on the electrical parts of the appliance fully disconnect it from the power supply (e. g.
Layout of Appliance 1 Layout of Appliance 1.1 combi 120 221.1 349 221.2 234.1 234 27 226 20 102 32.1 29 36 271 6 415 43 9 63 416 358 18 64 423 7 18.1 355 418 6.1 15 8.1 88 295 98 417 4 6 720 610 576-02.2O Fig. 1 4 6 6.1 7 8.1 9 15 18 18.1 20 27 29 32.
Layout of Appliance 1.2 system 120 221.1 349 221.2 234.1 234 27 226 20 102 32.1 29 36 271 6 415 43 9 63 416 358 18 64 423 7 18.1 418 15 8.1 295 4 417 6 720 610 596-01.2O Fig. 2 4 6 7 8.1 9 15 18 18.1 20 27 29 32.1 36 43 63 64 102 120 221.1 221.
Bosch Heatronic board functions 2 Bosch Heatronic board functions 2.1 Initialisation When it is switched on, the appliance performs a selftest which takes about 5 seconds. While the test is in progress, the display shows the following sequence of codes: P1 -> P2 -> P3 -> P4 -> P5 -> P6 On completion of the test sequence the appliance is ready for operation. 2.2 Temperature display 2.
Bosch Heatronic board functions The next time the central heating or heat store calls for heat, the appliance is held at a low heat output for 15 minutes. The display shows -II- in alternation with the CH flow temperature.The factory setting is 1 (enabled). If the condensation trap is not filled with water, flue gas can escape! B The trap filling programme should only be disabled in order to carry out servicing work. B Always re-enable the trap filling programme after completing servicing work.
Bosch Heatronic board functions 2.5 Boiler service functions 2.5.1 First Service Level Operating In order to change or check the values of the service functions: B Press the button until the symbol – – appears on the display. The button is lighted. B Turn the temperature control until the desired function number appears on the display. Once changed or checked the function value: B Press the button until the symbol [ ] appears on the display. The display shows the heating outlet temperature.
Bosch Heatronic board functions Values that can only be read: Description Display Reset Value .1 Heating outlet temperature. 0 - 99˚C - .2 Sanitary outlet temperature. 0 - 99˚C - .3 Heat store NTC sensor (ZSB.) 0 - 99˚C .4 Constant hot water NTC sensor (ZWB.) 0 - 99˚C - 1.2 Order no. for code plug: 8 714 411 XXX 0 - 255 - 1.4 Temperature voltage signal (Terminal 2) from room thermostat (eg. TRQ 21, TR 100) 5 - 22 VDC - 1.
Bosch Heatronic board functions Values that can only be read - only left display digit: Description Display XY Reset Value 3.9 External switch (points 8 - 9). 0 = closed 1 = Heating demand - 4.1 External demand for heat via LSM 0 = closed 1 = Heating demand - 4.2 Programmable clock: 1st channel (Heating). 0 = closed 1 = Heating demand - 4.3 Automatic pump shut OFF with RAM module (point 5) 0 = closed 1 = Heating demand - 4.4 Heating demand. 0 = closed 1 = Heating demand - 4.
Bosch Heatronic board functions 2.5.2 Secondary Service Level Operation In order to change or check the values of the service functions: B Press buttons and simultaneously until the symbol = = appears on the display. The buttons and are lighted. B Turn the temperature control until the desired function number appears on the display. Once changed or checked the function value: B Press buttons and simultaneously until the symbol [ ] appears on the display. The display shows the heating outlet temperature.
Bosch Heatronic board functions Values that can only be read: Description Display Reset Value 5.2 Automatic gas igniter status and/or fault 00 - FF - 9.3 Automatic gas igniter Asic fault code 00 - FF - Table 6 Secondary Service Level; Values that can only be read 12 7 181 465 346 GB (03.
Failure identification procedure 3 Failure identification procedure 3.1 Notes on using the fault code tables In this example: check the flue is clear by testing the CO2 level. The procedure is best described with the aid of an example: • Work through the table from top to bottom and from left to right. • First make a note of the present settings and restore them before leaving the appliance. • Read question 1.
Failure identification procedure ZWB ...A Page X X 42 Flue gas levels incorrect, CO level too high X X 43 3 X 17 Ignition too harsh, ignition poor. X X 44 A8 3 X X X 19 Boiler indicates P1, P2, P3 at start-up and then restarts with P1,...
Failure identification procedure 3.3 Error codes on the display A5 flashing. Heat store NTC sensor 2 defective Check Action B Note the setting of the temperature controls and 1. B Press button . yes: B Select service function .3 . Is a temperature between 0. and 5. displayed? 2. Heat store NTC: B Unplug connector. B Short circuit the connector. Display changes to temperature between 99. and 95. . B Flue gas connector corroded 1), damaged or dirty?. Change relative parts. ↓2. no: ↓3.
Failure identification procedure A5 flashing. Heat store NTC sensor 2 defective Check 5. Action To return to normal function mode: B Press buttons and simultaneously. B Regulate the temperature control and the temperature control on the previously set positions. 1) 16 For notes, refer to Appendix 7 181 465 346 GB (03.
Failure identification procedure A7 flashing. Hot water NTC sensor defective Check Action B Note the setting of the temperature controls and 1. B Press button . yes: B Select service function .2 . Is a temperature between 0. and 5. displayed? 2. Hot water NTC sensor: B Unplug connector. B Short circuit the connector. Display changes to temperature 99. . B Flue gas connector corroded 1), damaged or dirty? Change relative parts. ↓2. no: ↓3. yes: B B B B B B B Power OFF the appliance.
Failure identification procedure A7 flashing. Hot water NTC sensor defective Check 4. B Unplug 20-pin connector from PCB. After max. 60 sec.: Does the displayed code change to a value between 0. and 5.? Action yes: B B B B B Power OFF the appliance. Disconnect the boiler electrical connection. Change the 20-pin connector lead assembly. Reconnect the boiler electrical connection. Turn ON the appliance. ↓5.
Failure identification procedure A8 flashing. No correct electrical connection Check 1. TR 2 connected? Action yes: A8? ↓2. no: B Power OFF the appliance. B Connect TR 2. B Turn ON the appliance. A8? ↓2. 2. 3. B Turn switch until it clicks into position. Mode selector switch is between two settings A8? ↓3. B Power OFF the appliance. Wiring between TR 2 and TR 212 E OK? yes: • Terminal 3 on TR 2 connected to Terminal 3 on TR 212 E? no: • Terminal 4... Terminal 4....
Failure identification procedure AC flashing. Module not detected. (Constant CH flow temperature according to CH temperature control on boiler.) Check Action B Note the setting of the temperature controls and 1. B Press button . yes: B Select service function 1.9 . Code 0., 2., 4., 5. is displayed. . No modul detected. B Disconnect connecting lead between PCB control board and TA 211 E or TA 212 E. B Re-connect connecting lead. AC? ↓3. 2. 3.
Failure identification procedure AC flashing. Module not detected. (Constant CH flow temperature according to CH temperature control on boiler.) Check 7. Remote control status still 0.? Action yes: B Power OFF the appliance. Remote control: B Replace top section. B Turn ON the appliance. AC? ↓8. no: 8. The PCB control board is damaged. ↓8.
Failure identification procedure Ad flashing. Heat store NTC sensor 1 not detected (ZB...). Check Action B Note the setting of the temperature controls and 1. 2. . Is connecting lead for heat store NTC sensor 1 correctly routed, i.e. not through cable grommet? yes: ↓2. no: B Route connecting lead for heat store temperature sensor as specified in installation instructions. B Press button yes: Is NTC sensor connector corroded, damaged or dirty? B Power OFF the appliance. B Change NTC sensor.
Failure identification procedure Ad flashing. Heat store NTC sensor 1 not detected (ZB...). Check 4. Temperature between 99. and 95. is displayed. B Unplug connector. After max. 60 sec.: Does the displayed code change to a value between 0. and 5.? Action yes: B Power OFF the appliance. B Change NTC sensor. B Turn ON the appliance.
Failure identification procedure b1 flashing. The Heatronic does not recognise the code key. Check B Power OFF the appliance. 1. 2. Action Code plug loose, incorrect or defective. B Replace code plug, check code number is correct. B Turn ON the appliance. b1? ↓3. 3. 24 The PCB control board is damaged.
Failure identification procedure C1 flashing. Fan speed too low Check 1. Action Fan lead connector properly connected? yes: ↓2. no: B Power OFF the appliance. B Plug in connector. B Turn ON the appliance. C1? ↓2. 2. 3. Is fan lead defective? B Is impedance reading between the two connectors for one of the cores infinity? Are the differential pressure switch contacts closed? B Press button . yes: B Power OFF the appliance. B Replace fan lead. B Turn ON the appliance. C1? ↓3. no: ↓3.
Failure identification procedure CC flashing. Outside temperature NTC sensor not detected. (Boiler heating as if outside temperature is -20˚C) Check 1. Outside temperature sensor AF2 connected to Terminals A and F on TA 211 E? Action yes: ↓2. no: B Power OFF the appliance. B Connect outside temperature sensor to Terminals A and F on TA 211 E. B Turn ON the appliance. CC? ↓2. 2. 26 B Power OFF the appliance.
Failure identification procedure d3 flashing. Wrong signal from pin 8-9 (open?). Check 1. 2. Action B Turn ON the appliance. B Measure voltage between Terminal 4 and Terminal 8. Voltage ≅ 24 V DC? yes: ↓2. no: ↓3. Existing heat store thermostat connected to Terminals 7, 8 and 9? yes: B Power OFF the appliance. B Fix the additional bridge 8-9 in the right position and close the screws. B Turn ON the appliance. d3? ↓3. 3. Break in connecting lead? no: ↓4. yes: B Power OFF the appliance.
Failure identification procedure E2 flashing. The heating outlet NTC sensor is damaged. Check Action B Note the setting of the temperature controls and 1. B Press button . yes: B Select service function .1 . Is a temperature between 0. and 5. displayed? . The heating outlet NTC sensor is in short circuit: B Power OFF the appliance. B Replace CH flow NTC sensor; observe fitting instructions for NTC sensor when doing so. B Turn ON the appliance. E2? ↓2. 2.
Failure identification procedure E2 flashing. The heating outlet NTC sensor is damaged. Check Action To return to normal function mode: B Press buttons and simultaneously. B Regulate the temperature control and the temperature control on the previously set positions. 7 181 465 346 GB (03.
Failure identification procedure E9 and flashing. Safety temperature limiter has tripped. Check 1. Is the heating pressure between 1 and 2 bar? Action yes: ↓2. no: B Top up system. B Vent appliance. B Press , restart the appliance. E9? ↓2. 2. Is the pump blocked? yes: B Unblock the pump. If pump won’t start: B Power OFF the appliance. B Disconnect the boiler electrical connection. B Change the pump. B Reconnect the boiler electrical connection. B Turn ON the appliance.
Failure identification procedure E9 and flashing. Safety temperature limiter has tripped. Check 5. Is lead disconnected from CH flow safety temp. limiter? Action yes: B Power OFF the appliance. B Reconnect lead. B Turn ON the appliance. B Press , restart the appliance. ↓6. 6. B Power OFF the appliance. B Disconnect lead to CH flow safety temperature limiter. B Measure the CH flow safety temperature limiter. R = ∞? no: ↓6. yes: B Change CH flow safety temperature limiter.
Failure identification procedure EA and flashing. No flame ionisations signal Check Action B Note the setting of the temperature controls and 1. 2. Is the flame present? Is the gas cock open? . yes: ↓6. no: ↓2. yes: ↓3. no: B Open the gas cock. B Press , restart the appliance. EA? ↓3. 3. Is there air in the supply pipe? yes: B Vent supply pipe. B Press , restart the appliance. EA? ↓4. 4. Did the thermal security of the gas cock lock out? no: ↓4. yes: B Reset security.
Failure identification procedure EA and flashing. No flame ionisations signal Check 5. Natural gas models: does the building have a supply pressure regulator? Action yes: B Check that it is fitted correctly and functioning properly and correct if necessary. B Check supply pressure, inform gas company if outside correct range. B Is correct code plug fitted? B Press , restart the appliance. EA? ↓6. LPG models: is the flow rate of the gas supply to the appliance correct? no: ↓6. yes: ↓6.
Failure identification procedure EA and flashing. No flame ionisations signal Check 8. Is diaphragm in the mixer unit correctly fitted and functional? B Open mixer unit (29). B Check diaphragm for correct orientation, soiling and splitting. Is diaphragm OK? Action yes: B Close mixer unit. ↓9. no: B Insert diaphragm in the fan intake duct as per installation instructions so that the flaps open upwards. B Close mixer unit. EA? ↓9. 9.
Failure identification procedure EA and flashing. No flame ionisations signal Check 13. 14. Action B Press buttons and simultaneously. B Select service-function 5.1. Continuous ignition (without gas) OK? yes: Ignition lead connected to ignition electrodes? yes: ↓15. no: B Connect cable to ignition electrode. B Press buttons and simultaneously. and simultaneously. ↓14. no: B Press buttons ↓17. B Press , restart the appliance. EA? ↓15. 15.
Failure identification procedure EA and flashing. No flame ionisations signal 19. Check Action Check if the 20-pin connector lead assembly is damaged. B B B B B Power OFF the appliance. Disconnect the boiler electrical connection. Change the 20-pin connector lead assembly. Turn ON the appliance. Reconnect the boiler electrical connection. B Press , restart the appliance. EA? B Power OFF the appliance. ↓20. 20. The PCB control board is damaged.
Failure identification procedure F0 (and possibly ) flashing. Internal failure Check Action B Note the setting of the temperature controls and 1. 2. 3. . B Press buttons and simultaneously. B Select service function 9.3 . A service code is displayed. B Enter figure displayed in customer service record. B Select service function 5.2 . A service code is displayed. B Enter figure displayed in customer service record. flashing? ↓2. ↓3. yes: B Press button .
Failure identification procedure F7 and flashing. Although appliance switches off, flame still detected 1. Check Action Electrode(s) dirty or defective. B Power OFF the appliance. B Replace electrode assembly. B Turn ON the appliance. B Press , restart the appliance. F7? ↓2. 2. B Power OFF the appliance. B Disconnect the boiler electrical connection. B Remove PCB control board. PCB control board damp? yes: B Dry PCB control board (e.g. with hair dryer).
Failure identification procedure FA and flashing. Although appliance switches off, flame still detected Check Action B Note the setting of the temperature controls and . B Power OFF the appliance. 1. Condensation trap blocked? yes: B Clean condensation trap discharge pipe. B Press , restart the appliance. FA? ↓2. 2. Electrode assembly defective? B Power OFF the appliance. B Remove electrode assembly. Electrode assembly burnt out? no: ↓2. yes: B Replace electrode assembly.
Failure identification procedure FA and flashing. Although appliance switches off, flame still detected 5. Check Action Check if the 20-pin connector lead assembly is damaged. B B B B B Power OFF the appliance. Disconnect the boiler electrical connection. Change the 20-pin connector lead assembly. Turn ON the appliance. Reconnect the boiler electrical connection. B Press , restart the appliance. FA? B Power OFF the appliance. ↓6. 6. 40 The PCB control board is damaged.
Failure identification procedure Fd Button and flashing. pressed without necessity Check 1. Button Action is flashing. B Press , restart the appliance. Fd? ↓2. 2. The PCB control board is damaged. 7 181 465 346 GB (03.02) B Make a note of the altered service settings (see table 1, "First Service Level; Values that can be modified" at page 8 and table 5, "Secondary Service Level; Values that can be modified" at page 11). B Power OFF the appliance. B Disconnect the boiler electrical connection.
Failure identification procedure 3.4 Faults that are not displayed 3.4.1 Appliance faults Excessive burner noise, rumbling noises Check Action B Note the setting of the temperature controls and 1. Does the gas supply type match the specifications on the appliance identification plate? . yes: ↓2. no: B Convert appliance to correct gas type. ↓2. 2. 3. 4. B Test gas supply pressure - OK? Does pressure match figure specified in installation instructions? yes: ↓3.
Failure identification procedure Excessive burner noise, rumbling noises 7. Check Action B Press buttons and simultaneously. B Select service-function 5.9. 0 is displayed. B Set to 1 for high start-up speed. Flue gas levels incorrect, CO level too high Check 1. Does the gas supply type match the specifications on the appliance identification plate? Action yes: ↓2. no: B Convert appliance to correct gas type. ↓2. 2. 3. 4. 5. yes: ↓3. no: B Decommission appliance. B Notify gas company.
Failure identification procedure Ignition too harsh, ignition poor Check Action B Note the setting of the temperature controls and 1. 2. . B Press buttons and simultaneously. B Select service-function 5.1. Continuous ignition (without gas) OK? yes: ↓6. no: ↓2. Ignition lead connected to ignition electrodes? yes: ↓3. no: B Connect cable to ignition electrodes. B Press button . Ignition poor? ↓3. 3. Ignition cable connector engaged in switchbox? yes: ↓4. no: B Power OFF the appliance.
Failure identification procedure Ignition too harsh, ignition poor Check 6. 7. 8. 9. Action Does the gas supply type match the specifications on the appliance identification plate? yes: ↓7. no: B Carry out gas type conversion as described in installation instructions. B Test gas supply pressure - OK? yes: ↓8. no: B Decommission appliance. B Notify gas company. Problem with flue? B Check CO2 level in combustion air.
Failure identification procedure Loose or broken contact on heat store NTC sensor 1. Check Action Heat store NTC sensor lead is not fitted as described in the installation instructions (i.e. the cable does not pass through the cable grip in the switchbox). B Record condition of appliance as found in customer service record. B Route cable as specified in installation instructions. Boiler indicates P1, P2, P3 at start-up and then restarts with P1.. Check 1. Fuse T 1,6 A (312) defective.
Failure identification procedure Specified CH flow temperature from TA... programmer exceeded Check Action B Note the setting of the temperature controls and . If outside-temperature controlled programmer (TA...) is connected to boiler: • The anti-cycle time is adjusted by the programmer to the suit the system. • The factory setting for the anti-cycle time (3 min.) and the heating mode hysteresis setting, if applicable, are deactivated.
Failure identification procedure Condensation in the flue pipe 1. 3.4.2 Check Action Is diaphragm in mixer unit fitted correctly (see installation instructions)? B Open mixer unit (29). B Check diaphragm for correct orientation, soiling and splitting. B Fit diaphragm as per installation instructions or replace. B Close mixer unit. Programmer faults Set room temperature not reached (TR 2 and TR 212 E) Check 1. Thermostatic valve(s) set too low? Action yes: B Turn up thermostatic valve(s). ↓2.
Failure identification procedure Set room temperature not reached (TA 211 E und DT 2) Check 1. Thermostatic valve(s) set too low? Action yes: B Turn up thermostatic valve(s). ↓2. 2. Heating characteristic set too low? no: ↓2. yes: B Correct heating characteristic. ↓3. 3. 4. CH flow temperature control on boiler set too low? Is heat store temperature unreachable (CH flow temperature control set too low)? no: ↓3. yes: B Turn up CH flow temperature control. ↓4. no: ↓4.
Failure identification procedure Set room temperature exceeded by large amount Check 1. Do radiators get too hot? Action yes: TR 2: B Decrease setting of “Heating” control TA 211 E: B Correct heating characteristic. ↓2. 2. Bad choice of location for programmer, e.g. outside wall, near window, in draught, on hollow wall, etc. no: ↓2. yes: B Select better installation location. -orB Fit external room thermostat. ↓3. no: ↓3. B Turn down thermostatic valve(s). 3.
Failure identification procedure Temperature rises instead of falling Check Action Timer clock (DT 2) incorrectly set B Check setting and correct as necessary. Incorrect or no modulation Check Action Programmer incorrectly wired B Check wiring against wiring diagram and correct as necessary. 7 181 465 346 GB (03.
Appendix 4 Appendix 4.1 NTC values 4.1.1 Outside temperature sensor 4.1.
Appendix 4.2 Electronic schemes o - orange g - green bl - black r - red p - purple 33 365 364 61 317 366 363 367 ECO 4.1 25 V 153 230V/AC 230 V 310 136 135 312 328 302 313 151 318 315 124 789 L N Ns Ls LR 161 p p p 300 314 84 M 96 328.1 9 M mains supply 18 g 6 M g o r r o 226 52 52.1 56 o o bl bl bl bl 36 bl 6.1 32 6 720 610 576-08.2O 4.1 6 6.1 6.3 18 32 33 36 52 52.
Appendix 4.3 List of most important replacement parts Component Order no. Remarks Switchbox PCB control board 8 748 300 385 Transformer 8 747 201 358 Ignition lead 8 714 401 999 20-pin connector lead assembly 8 714 402 087 20-pin connector lead assembly 8 714 402 086 Fuse 1 904 552 730 T 0,5 A Fuse 1 904 552 740 T 1,6 A Fuse 1 904 521 342 T 2,5 A Set of fuses 8 744 503 010 Switchbox kpl. 8 717 207 514 with DT 2 Switchbox kpl. 8 717 207 513 without DT 2 Component Order no.
Appendix 4.4 Approved corrosion inhibitors and anti-freeze fluids for central heating water If any system water treatment is required then only products suitable for use with Aluminium shall be used i.e Fernox- Copal or Superconcentrate or Sentinal X100, in accordance with the manufacturers instructions. The use of any other substances will invalidate the guarantee. The pH value of the system water must be less than 8 or the appliance guarantee will be invalidated. 4.4.
