Bosch Worchester GREENSTAR ZWB 7-27 HE combi Installation And Servicing Instructions Download Page 46

Page: 46 / 48

72
0

610

576

(02.
05)

App

nd
ix

9.5

per

ona

l Fl
o

w d

iagr

m
s

.5.

m
es
ti

ho
t w

te
r

fun

Fig.

Mains

switch

ON.

Green

light

ON.

Burner lights.

Red light ON.

Ignition spark for

5 seconds.

Fan runs to purge

gas from burner.

Repeats 5 times

before lock-out.

Hot

water

demand.

Pump ON

Diverter valve

operates.

Heat input

modulates to

maintain the

delivery

temperature.

Gas valve

closes.

Red light

OFF.

Fan runs for
upto 3 mins.

Pump runs

for 30secs.

Over temperature

shut-down if water

temperature is 8

above set value.

Burner remains OFF

until flow temperature

is below set value.

Gas valve shuts.

Pump remains ON.

Demand

ends.

Yes

** NOTE:
The appliance controls can be set to one of
2 modes of operation.

“

Comfort

“ mode -

Full pre-heat

“

ECO

“ mode -

a) Operates as an instantaneous combination
boiler.
b) Demand Detection: a short demand (less
than 5 seconds) switches the control to
“Comfort“ mode for 5 mins. Mini pre-heat.
The Factory setting is “

Comfort

“ mode.

Fan to

start speed.

Gas valve opens.

Pre-heat

mode.**

Ignition sequence

Pre-heat

mode.**

Burner shut-down if

primary temperature

exceeds 94

C remains

OFF until 78

Pump ON

Diverter valve

operates.

Fan to

start speed.

Gas valve opens.

Pre-heat satisfied.

Ignition sequence

Burner lights.

Red light ON.

Ignition

spark

5 secs

6 720 610 576 - 24.1O

Summary of Contents for Worchester GREENSTAR ZWB 7-27 HE combi

Page 1: ...and Servicing Instructions GREENSTAR HE combi Wall mounted condensing boiler for central heating and mains fed domestic hot water 6 720 610 577 00 10 ZWB 7 27 HE combi GC Number 47 311 55 6 720 610 576 GB 02 05 OSW ...

Page 2: ...w temperature 26 6 1 3 Changing the heating pump characteristic 26 6 2 Settings on the Bosch Heatronic 27 6 2 1 Operating the Bosch Heatronic 27 6 2 2 Selecting the pump control mode for central heating mode Service Function 2 2 27 6 2 3 Setting the anti cycle time Service Function 2 4 27 6 2 4 Setting the maxim CH flow temperature Service Function 2 5 28 6 2 5 Setting the switching difference Ser...

Page 3: ...nity of the appliance Health and safety B This appliance contains no asbestos products B There is no potential hazard due to the appliance being electrically unsafe B There are no substances used in the construction that are a potential hazard in relation to the COSHH Regulations Control of Substances Hazardous to Health Regulations 1988 Combustion air Ambient atmosphere B The combustion air ambie...

Page 4: ...ting not dependent on room size Natural gas models are low emission appliances Multifunction display Bosch Heatronic control system Automatic ignition Modulating control Full safety systems incorporating Bosch Heatronic with flame ionisation monitoring solenoid valves and temperature sensors Concentric flue air duct with testing point for CO2 CO Regulated speed fan Pre mix burner Temperature contr...

Page 5: ... with these kits Heating programmer Timer Security kit 1 5 Casing dimensions Fig 1 13 Manifold assembly 101 Outer case 103 Facia cover X Standard Concentric Horizontal Flue System min 310 mm Alternative Concentric Flue System min 250 mm Y Standard Concentric Horizontal Flue System 158 mm Alternative Concentric Flue System 121 mm Z Standard Concentric Horizontal Flue System 105 mm Alternative Conce...

Page 6: ...sting screw for min gas flow volume 88 3 way valve combi 98 DHW flow switch combi 102 Inspection window 120 Fixing points 221 1 Flue duct 221 2 Combustion air intake 226 Fan assembly 295 Appliance type sticker 234 Testing point for combustion products 234 1 Testing point for combustion air 271 Flue duct 349 Cover plate for twin flue duct connection 355 Plate type domestic hot water heat exchanger ...

Page 7: ...combustion chamber 36 Temperature sensor in CH flow 43 CH flow 44 Hot water flow 45 Gas inlet 46 Cold water inlet 47 CH return 52 Solenoid valve 1 52 1 Solenoid valve 2 55 Filter 56 Gas valve CE 427 57 Main valve disc 61 Reset button 63 Adjustable gas flow restrictor 64 Adjusting screw for min gas inlet flow volume 69 Control valve 84 Motor 88 3 way valve 90 Venturi 91 Pressure relief valve 93 Wat...

Page 8: ...er 161 Link 226 Fan 300 Code plug 302 Earth connection 310 Temperature control for hot water 312 Fuse slow T 1 6 A 313 Fuse slow T 0 5 A 314 Connector for programmer 315 Terminal block for programmer 317 Digital display 318 Connector for timer 328 Terminal block for AC 230 V Mains supply 328 1 Link 363 Indicator lamp for burner 364 Indicator lamp for power supply 365 Chimney sweep button 366 Servi...

Page 9: ... 10 10 Hot water specifications Hot water flow rate factory setting l min 8 8 Max hot water flow rate l min 14 14 Outlet temperature range C 40 60 40 60 Max permissible water supply pressure bar 10 10 Min inlet pressure bar 0 2 0 2 Specific flow rate l min 12 4 12 4 Flue Flue gas temp 80 60 C rated min load C 67 55 67 55 Flue gas temp 40 30 C rated min load C 43 32 43 32 Residual delivery pressure...

Page 10: ...uct Length Fixed mm 200 Extension Duct Length Fixed mm 450 Extension Duct Length Fixed mm 950 Extension Duct Length Fixed mm 1950 Extension Duct Length Telescopic mm 265 375 Extension Duct Length Adjusta ble Cut to length mm 200 Table 5 VERTICAL 125 mm FLUE SYSTEM Overall Diameter of Duct mm 125 Max 15 m Flue Terminal Duct Assembly mm 1360 Extension Duct Length mm 200 Extension Duct Length Fixed m...

Page 11: ...plies for domestic purposes BS 5440 1 Flues and ventilation for gas appliances of rated input not exceeding 70 kW gross Flues BS 5440 2 Flues and ventilation for gas appliances of rated input not exceeding 60 kW gross Air Supply BS 6891 Installation of low pressure gas pipework installations up to 28mm R1 BS 7074 1 Code of practice for domestic heating and hot water supply These instructions must ...

Page 12: ...at ing system An isolating valve should be fitted to allow for servicing Devices such as water meters or back flow preven tion valves capable of preventing the flow of expan sion water must not be fitted unless separate arrangements have been made A Zilmet Z160 expansion vessel is the preferred type A thread sealant compatible with potable water must be used 3 3 Sealed systems The appliance must n...

Page 13: ...casing and the flue is less than 85 C This means that no special safety precautions are required with regard to flammable building materials and fitted furniture The specified clearences must be maintained Cupboard Compartment The appliance can be installed in a cupboard compart ment need for airing clothes providing that the require ments of BS6798 and BS5440 2 are followed The low casing losses ...

Page 14: ...ed Refer to fig 1 and 15 B Mark the holes for the wall mounting frame onto the wall drill and plug the holes and screw the wall mounting frame to the wall with the screws provided Fig 8 B Screw the pre plumbing manifold with two screws to the wall mounting frame Fig 9 3 6 Pre piping the system Fig 10 Manifold 43 CH flow 47 CH return 112 Gas cock 171 Domestic hot water 172 Cold water relief B A dra...

Page 15: ...s on the packing B Lie the boiler on its back Removing the outer case B Turn the clips with a screwdriver 1 B Slide the outer case upwards and then forwards to remove 2 B Remove the plastic caps from the boiler connections Fig 12 Fixing the appliance B Fit the washers onto the gas and water connections B Lift the boiler onto the wall mounting frame The lugs pass through the rectangular holes in th...

Page 16: ... the gas supply pipe 3 9 Flue Systems The only flue systems that may be used are those sup plied by Worcester Heat Systems The flue system must be installed in accordance with the requirements of BS5440 1 Standard 100 mm flue system The standard concentric flue system provides for a hor izontal length of upto 4 m Full instructions for fitting this flue are in Subsection 3 9 2 Installation of the f...

Page 17: ...ig 14 Dimension Terminal Position kW input expressed in net Balanced flues room sealed Fanned draught A1 Directly below an opening air brick opening windows etc 300 mm B 1 Above an opening air brick opening window etc 300 mm C 1 Horizontally to an opening air brick opening window etc 300 mm D Below gutters soil pipes or drain pipes 75 mm E Below eaves 200 mm F Below balconies or car port roof 200 ...

Page 18: ...ng plates Extension kit comprises Air duct Flue duct Duct clamp Refer to fig 19 Instructions for fitting other flue systems are packed with the relevant flue kit Check that the position chosen for the appliance is sat isfactory Refer to fig 15 Fig 15 Marking the position of the side flue opening Fig 16 Standard Flue Appliance 120 Drilling point for flue duct opening 3 30 mm meter Centre line of fl...

Page 19: ... 1600mm Flue Turret No Clamp Terminal Assembly Outer Wall Extension Duct 6 720 610 602 09 1O Clamp Flue Turret No Clamp Clamp Extension Duct Clamp Extension Duct Terminal Assembly Outer Wall 6 720 610 602 10 1O Extension Air Duct Extension Flue Duct Terminal Assembly Duct Clamp Wall Sealing Plates 6 720 610 602 11 1O Flue Turret ...

Page 20: ... An inner wall sealing plate is provided which should be fitted to the ducts before assembly Push the assembly through the wall and fix the turret to the appliance with the clamp Refer to fig 23 Fig 23 Flue turret Ensure that the turret is fully entered into the socket on the boiler From the outside fix the outer wall plate to the terminal and after ensuring the duct is properly i nclined towards ...

Page 21: ...x 0 20 mm to BS6500 Table 6 Temperature rated 100 C Protection IPX4D External fuse 3 A 4 1 Connecting the appliance To gain access to the mains connection remove the drop down facia cover The drop down cover is removed by lowering it to the horizontal position and pushing firmly upwards at the rear of the supports to release the cover Lift cover from the appliance After installation or in the even...

Page 22: ...2 3 4 5 E 6 720 610 332 12 1R 13 14 10 12 8 9 5 7 L N N L LR S S 4130 14 1R 230 VRoom Thermostat Connections Ns Ls LR ST8 Ns Ls LR ST8 Remove Link Neutral Live Switched Live Neutral Live Switched Live Motor 230 V Programmer Connections 230 V room thermostat and Programmer Connections Ns Ls LR ST8 Neutral Live Neutral Live S w i t c h e d L i v e Motor S w it c h e d L iv e Series connection to be ...

Page 23: ... its associated cen tral heating system should be flushed in accordance with the guidelines given in BS7593 1992 Treatment of water in domestic hot water systems Full instructions are supplied with proprietary cleansers sold for this pur pose If an inhibitor is to be used after flushing it should be used in accordance with the inhibitor manufacturers instructions To drain the appliance shut the sy...

Page 24: ...or 15 minutes Switching off the appliance B Set the master switch to 0 The green indicator lamp goes out 5 3 Switching on the central heating The central heating flow temperature is adjustable between 35 C and 88 C Refer to table 12 page 26 B Turn the temperature control to set the flow tem perature to a level appropriate to the type of central heating system Underfloor heating e g setting 3 appro...

Page 25: ...3 5 6 Summer mode hot water only With room thermostat B Turn temperature control on the appliance anti clockwise as far as the stop The central heating is now turned off The hot water function and the mains power supply for the heating programmer and timer remain switched on 5 7 Frost protection B Leave master switch switched on If the appliance is to be left for long periods switch the central he...

Page 26: ...ver Fig 34 B Rotate yellow button through 180 and replace dot facing inwards The CH flow temperature is no longer limited 6 1 3 Changing the heating pump characteristic The speed of the central heating pump can be altered on the pump terminal box Fig 35 1 Pump characteristic for switch position 1 2 Pump characteristic for switch position 2 3 Pump characteristic for switch position 3 H Residual del...

Page 27: ...2 2 The choice of settings is as follows Control Mode 1 For heating equipment without a control unit The pump is controlled by the central heating flow temperature control Control Mode 2 factory setting For heating systems with room thermostat The central heating flow temperature control controls only the gas the pump is not affected The room ther mostat controls both the gas and the pump The pump...

Page 28: ...mpare with the fig ures specified for the code number displayed If fig ures do not match adjust the code number B Press and hold the and buttons simultane ously until the display shows The heating output is now stored Fig 39 B Return the temperature controls and to their original positions The display will revert to the CH flow temperate 6 2 7 Constant hot water cycle time Service Function 6 8 In ...

Page 29: ...e appliance at the master switch O B Remove the outer case see page 15 refer to fig 12 B Switch on the appliance at the master switch I B Unscrew sealing plug from flue gas testing point 234 Refer to fig 40 B Insert testing probe about 135 mm into the flue gas testing point and seal testing point Fig 40 B Press and hold button until the display shows The button will light up Fig 41 B Turn the temp...

Page 30: ...iven in Table 15 for min rated heat output Fig 46 B Measure the CO level If the CO level is over 300 ppm the gas volumetric flow rate is too high Reduce the gas flow rate on the adjustable gas flow restrictor 63 until the CO level is below 100 ppm B Re adjust the CO2 level if necessary B Recheck the levels at min and max rated heat output and re adjust if necessary B Turn the temperature control a...

Page 31: ...active The button will light up and the display shows the CH flow temperature B Remove sealing plug from flue gas testing point 234 fig 47 B Insert testing probe about 135 mm into the testing point and seal testing point B CO and CO2 levels B Refit sealing plug B Press and hold button until the display shows The button will stop flashing and the display shows the CH flow temperature i By testing t...

Page 32: ...con based grease Unions approved sealant B To drain the appliance shut the system valves and open the pressure relief valve B Always disconnect the appliance from the electrical power supply fuse circuit breaker before carrying out any work on the electrical systems or components B Always turn off the gas cock before car rying out any work on components which carry gas i There is a Service booklet...

Page 33: ... flue gas see page 31 6 Check CO2 setting for min max gas air ratio see page 29 min max 7 Check gas and water systems for leaks see page 16 8 On combi models check hot water outlet temperature see page 34 9 Check heat exchanger see page 34 mbar 10 Check burner see page 35 11 Clean condensation trap see page 36 12 Check charge pressure of expansion vessel matches static head of heating system mbar ...

Page 34: ...cleaned or replaced Domestic hot water If the flow rate is too slow B remove the domestic hot water heat exchanger and replace or B descale with a descaling agent approved for use on stainless steel B Before removing the heat exchanger shut the inlet valve and drain the hot water circuit B Use new seals when replacing the heat exchanger Fig 48 Primary Heat exchanger There is a special accessory ki...

Page 35: ...g a new seal and tighten screws to torque of approx 5 Nm Burner B Check that the gas cock is turned off and the master switch is in the OFF position B Remove the clips 1 and unscrew the two bolts 2 Refer to fig 54 B Unscrew and remove the two hexagon screws secur ing the fan 3 B Slacken fully the rear securing bolt 4 B Remove the burner coverplate Fig 54 B Remove burner and clean components Do not...

Page 36: ...e assembly B Switch off the master switch B Pull off the leads from the electrodes Refer to fig 2 B Unscrew the two fixing screws and carefully remove the electrode assembly Refer to fig 49 B Clean the electrodes with a non metallic brush The spark gap should be 4 5 mm 0 5 mm B Replace and re connect the assembly taking care not to mislay the inspection window Siphon B Unscrew the clip and disconn...

Page 37: ...ter should be added until the pointer is 1 bar again B Max pressure of 2 5 bar when the heating system water is at maximum temperature must not be exceeded If this pressure is exceeded then an extra expansion vessel must be fitted in the system return as close to the appliance as possible B If the system does not retain the pressure the expan sion vessel and the heating system should be checked fo...

Page 38: ...to fig 24 25 B Remove screw holding power connector earth lead and remove earth lead B Remove two top fixing screws from the control box Refer to fig 58 Fig 58 B Lower the control box B Unscrew earth lead B Unscrew four fixing screws from cover plate Refer to fig 59 B Prise off cover plate B Pull off transformer B Remove pcb holder B Remove the pcb control board Fig 59 Fuses B Remove the connectio...

Page 39: ...it B Separate the fan from the pipe and mixer unit by twisting the mixer unit to release it 4 8 3 3 Pump B Switch off the appliance B Disconnect the appliance from the power supply B Remove two switchbox fixing screws 1 Refer to fig 61 B Lower switchbox 2 B Unscrew and remove the the siphon by releasing the jubilee clip Refer to fig 57 B Unscrew the pump union nuts 3 Refer to fig 61 B Carefully re...

Page 40: ...B Unplug connector from 3 way valve motor Refer to fig 62 B Pull out retaining clip B Remove motor 8 3 6 Sensors B Check that the appliance is electrically isolated Central Heating Flow Temperature Sensor Item 36 fig 2 58 B Pull off the connector B Release the sensor clip and withdraw the sensor B Apply heat transfer paste to the replacement sensor Safety Temperature Limiter Item 6 fig 2 58 B Pull...

Page 41: ...ls when fitting the new heat exchanger 8 3 9 Electrode assembly B Refer to section 7 2 B Use a new seal if the existing seal is damaged 8 3 10 Pressure gauge B Drain the appliance B Lower the facia Refer to fig 61 B Twist the pressure gauge head anti clockwise to release it from the casing Refer to fig 2 B Disconnect the capillary head from the rear of the diverter valve by withdrawing the clip an...

Page 42: ...burner Refer to section 8 2 B Disconnect the sensors Refer to section 8 3 6 B Undo the central heating flow union B Undo the top connection of the pump Refer to fig 61 B Undo the grey plastic cap next to the top pump con nection at the base of the heat exchanger B Unscrew and remove the condensate trap Refer to section 8 2 B Unscrew and remove the two screws securing the heat exchanger top bracket...

Page 43: ...pped E2 CH flow NTC sensor defective Check CH flow NTC sensor and connecting lead E9 Safety temp limiter in CH flow has tripped Check system pressure check safety temp limiters check pump operation check fuse on pcb bleed appliance EA Flame not detected Is gas cock turned on Check gas supply pressure power supply igniter electrode and lead ionisation sensing electrode and lead flue duct and CO2 le...

Page 44: ...ief valve 1 8 717 401 012 0 10 Electrode assembly 1 8 718 107 077 0 11 Electrode lead 1 8 714 401 999 0 12 Pump 1 8 717 204 477 0 13 Pressure gauge 1 8 717 208 079 0 14 Burner skin seal 1 8 711 004 168 0 15 Transformer facia 1 8 747 201 358 0 16 Flow switch 1 8 717 002 110 0 17 3 way diverter valve 1 8 717 010 062 0 18 Heat exchanger washer 1 8 710 103 153 0 19 Washerset Condenstaion Trap 1 8 710 ...

Page 45: ...t kW Heat input kW Gas vol flow rate l min at tV tR 80 60 C 30 8 2 8 3 14 4 40 10 9 11 0 19 3 50 13 6 13 8 24 1 60 16 3 16 5 28 9 70 19 1 19 3 33 7 80 21 8 22 0 38 5 90 24 5 24 8 43 3 100 27 2 27 5 48 1 Table 19 Propane Display code Heat output kW Heat input kW 40 10 9 11 0 50 13 6 13 8 60 16 3 16 5 70 19 1 19 3 80 21 8 22 0 90 24 5 24 8 100 27 2 27 5 Table 20 ...

Page 46: ...until flow temperature is below set value Gas valve shuts Pump remains ON Demand ends Yes No NOTE The appliance controls can be set to one of 2 modes of operation 1 Comfort mode Full pre heat 2 ECO mode a Operates as an instantaneous combination boiler b Demand Detection a short demand less than 5 seconds switches the control to Comfort mode for 5 mins Mini pre heat The Factory setting is Comfort ...

Page 47: ... Burner stabilises at start speed for 5 10 secs Fan speed reduces over 15 secs Gas valve closes Red light OFF Minimum heat input for 15min Boiler operates to match system load and CH control setting Boiler unused for long period Over temperature shut down if water temperature is 5 C above set value Burner remains OFF until flow temperature is below set value Gas valve shuts Pump remains ON Pump an...

Page 48: ...Appendix Appendix EXCELLENCE COMES AS STANDARD Worcester Heat Systems Limited Cotswold Way Warndon Worcester WR4 9SW Telephone 01905 754624 Fax 01905 754619 ...

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Bosch Worchester GREENSTAR ZWB 7-27 HE combi, Installation And Servicing Instructions

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