background image

30

17. Operational Flow Diagram

Facia 

light

ON

BOILER

HEA

T

DEMAND

If HL st

at 

has tripped,

4 second

dela

y

CH

only

demand

CH selected

on timer &

room calling.

In addition f

o

r

Y plan:

DHW

selected

on timer &

tank satisfied 

or

DHW off 

signal fr

om

timer

.

Pump 

continues

fo

r

3

minutes

DEMAND

END

DHW

only

demand

DHW

selected

on timer

, t

ank

st

at calling

DHW &

C

H

demand

DHW & CH

selected on

timer

, t

ank

st

at calling,

ro

om st

at 

calling.

Facia contr

ol

knob abo

ve

position 'I'

Fan 

ON

Pump 

ON

20 

second

dela

y

R

eset 

on 

fa

ci

a

APS 

ON

LOCK

OUT

(all outputs OFF

EXCEPT pump)

Gas v

alv

e

and

sparking

ON

Flame

sense

No flame 

sense f

or 

seconds

Burner ON.

This sequence

is cy

cled t

o

satisfy 

temper

atur

e

set b

y

 f

acia 

contr

ol knob.

Temper

atur

e

Sensor disconnected.

Fan and burner OFF

.

Pump running.

Failed ignition

Ov

erheat of

gas t

o

 w

ater

heat ex

changer

Ov

erheat 

thermost

at

trip.

Gas v

alv

e not 

ener

gised during

ignition r

ecy

cle.

Burner

LOCK

OUT

R

eset

using f

a

cia

red butt

on

CH    

= Central Heating

DHW = Domestic Hot W

ater

Pr

otection Sy

stems

Summary of Contents for Worcester 15SBi

Page 1: ...ER 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 15 0 kW Maximum 24 0 kW 24 0 kW 15SBi Minimum 6 0 kW 6 0 kW Maximum 15 0 kW 15 0 kW IMPORTANT THESE INSTRUCTIONS APPLY IN THE UK ONLY AND MUST BE LEFT WITH THE USER OR AT THE GAS METER Read the instructions before starting work they have been written to m...

Page 2: ...rmation The appliance is set to give the mid range output of 19 5kW 24SBi or 10 8kW 15SBi Kits are available to convert the appliance from Natural Gas to Propane operation and vice versa 2 2 Electrical Supply 230V 50Hz Load 180 watts External fuse 5A Internal fuse F1 4A 2 3 Gas supply The 24SBi appliance requires a maximum of 2 86 m3 h of natural gas G20 or 1 1 m3 h of propane G31 The 15SBi applia...

Page 3: ...ack flow prevention devices including water meters are fitted the expansion of hot water into cold water main can be prevented This can result in a pressure build up that may cause damage to the boiler and household devices such as showers washing machines etc In these cases we recommend that a mini expansion vessel be fitted adjacent to the boiler in the cold water pipe 2 10 Operation Central Hea...

Page 4: ...Natural Gas OUTPUT INPUT Net GAS RATE 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 86 BOILER ADJUSTED FOR G31 Propane 15 17 5 13 5 0 72 19 5 22 1 22 5 0 9 24 27 35 5 1 1 Table 1 24SBi FLUE DETAILS HORIZONTAL FLUE mm WALL HOLE DIAMETER EXTERNAL FIX 110 INTERNAL FIX 150 STANDARD FLUE MINIMUM LENGTH 100 MAXIMUM LENGTH 725 EXTENDED FLUE MAXIMUM LENGTH 4000 FLUE ASSEMBLY DIAMETER 100...

Page 5: ...res INITIAL INITIAL CHARGE PRESSURE bar PRESSURE bar 0 5 1 0 1 5 1 0 72 92 N A 1 5 39 53 64 Table 8 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...

Page 6: ...The appliance can be installed in a cupboard compartment to be used for airing clothes providing that the requirements of BS6798 and BS5440 2 are followed Refer to Section 2 4 The clearance between the front of the appliance and the cupboard compartment door should be not less than 250mm LPG Installation Refer to Section 1 10 4 Siting The Appliance 6 Fig 2 Appliance casing dimensions and required ...

Page 7: ...that does not allow these clearances then permanent air vents are required in the compartment one at a high level and one at a low level Both high and low level air vents must communicate with the same room or must both be on the same wall to the outside air The minimum requirements are 6 Air Supply 5 Flue terminal positions 7 L L K K F F G A M E J F HI D G A B C Fig 4 Siting of the flue terminal ...

Page 8: ... NOT suitable for direct water supply Do not connect to a direct cylinder The SBi can be connected to any indirect cylinder i e unvented or thermal store all the benefits of a dry loft and mains pressure hot water can be realised Refer to a separate leaflet or contact Worcester Heat Systems Technical Helpline 0990 266241 8 Domestic Hot Water 7 Sealed System 8 Fig 5 System layout if using built in ...

Page 9: ...ustment RV LV LV RV RV RV LV LV INDIRECT CYLINDER APPLIANCE Refer to fig 1 Appliance Water Flow Diagram Heating Return Heating Flow Safety Discharge Cylinder Return Hot Water Flow BS Stop Valve Fixed Cylinder Type Mains Cold Water Radiator Valve Flow RV Lockshield Valve Return LV Note A drain cock should be fitted at the lowest point of the heating circuit and beneath the appliance CH Zone Valve D...

Page 10: ...fused three pin plug and unswitched socket outlet both complying with BS1363 or a double pole isolator with a contact separation of 3mm in all poles NOTE There must be no other permanent electrical supply to the system This ensures the safety of a single fused supply A room thermostat must be suitable for mains voltage operation A mechanical timer to fit into the facia is available A frost thermos...

Page 11: ...lectrode Gas Valve Air Flow Switch Mid Position Valve Y Plan Optional Facia Mounted Timer Optional Cylinder Thermostat Overheat Cut off Fan Control Board X1 X10 1 1 1 X11 X12 X2 X3 X4 X5 X6 br bl bl y bl bl Blue br Brown y Yellow g Green 1 br br br 2 orange 2 red 2 green Pump ...

Page 12: ... 1 Cylinder Thermostat Satisfied Call C Y O S X5 Top Pin X5 Top Pin X4 Top Pin Pump Fan N N N N Reset Button Temperature Control Temperature Sensor Air Flow Switch Flame Sense N N Mid Position Valve white grey orange Y Plan S Plan Zone Valve CH Spark Boiler Demand Electronics High Voltage Safety Low Voltage Fan Pump Gas Valve X3 Pin 1 X3 Pin 4 X3 Pin 3 Overheat Thermostat X3 Pin 2 A Mid Position V...

Page 13: ...he 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 Before the appliance is connected to the wall manifold thoroughly flush the sys...

Page 14: ...k the maximum flue length and if it is less than 1m total overall length then fit the restrictor ring as shown in Fig 21 24SBi 75mm Horizontal flue up to 1m 75mm Vertical flue up to 1m 15SBi 74mm Horizontal flue up to 1m 79mm Vertical flue up to 1m The standard telescopic flue assembly is suitable for flues from 425mm up to 725mm measured from the centre line of the boiler flue outlet to the outer...

Page 15: ...m accommodating a 10mm Service clearance and a 100mm wall Minimum rear flue length 296mm accommodating a 100mm wall If L is between 1175 1475mm 1 extension 1925 2225mm 2 extension 2675 2975mm 3 extension 3425 3725mm 4 extension it is not necessary to cut the ducts 15 Fig 22 Standard flue assembly Appliance casing Fixing screw Turret assembly Terminal assembly L Fig 20 Mid position diverter valve O...

Page 16: ... 11 10 Fitting of the Flue Assembly without access to the Terminal The rubber gasket kit is available from Worcester Heat Systems NOTE A larger diameter opening opening in the wall is required Refer to Table 2 Prepare the flue assembly as descried in Section 11 8 Fit the rubber sealing gasket centrally onto the terminal assembly and tighten the clamp Refer to Fig 27 Apply the plastic tape to the a...

Page 17: ...l be necessary to cut the air and flue ducts of the extension to a plain length of 100mm and reduce the length of the terminal assembly i e Z 350mm remove 75mm from the terminal assembly If Z in 425 725mm it is not necessary to cut the terminal assembly or use a second extension duct as the length can be set telescopically If Z 725mm then two extension duct assemblies will be required the first as...

Page 18: ...y cable is longer than the live and neutral leads Fit the facia mounted clock Refer to Fig 34 Connect any external controls ensuring that the leads pass through the appropriate clamps refer to Fig 12 and 33 Test for gas soundness as described in BS6891 If the appliance is not commissioned immediately replace the cabinet and facia bottom panel Check that the gas and electricity services have been t...

Page 19: ...anti clockwise until it releases Refer to Fig 37 12 2 Set the Expansion Vessel Pressure The charge pressure of the expansion vessel as dispatched is 0 5bar which is equivalent to a static head of 5m 17ft The charge pressure must not be less than the static head at the point of connection A Schraeder type valve is fitted to the expansion vessel to allow the charge pressure to be increased if necess...

Page 20: ...t all the radiators heat up evenly If necessary carefully vent 12 9 Balance the system to give a temperature differential of 11 C An adjustable by pass is fitted to the appliance 12 10 Set the room thermostat to minimum and check that the burner goes out Reset the room thermostat and the burner will re light Turn off the gas service cock The burner will go out but after a short pause the appliance...

Page 21: ...hdraw the hood Ensure that the replaced hood passes under the lip at the rear of the appliance Burner Remove the combustion chamber Release the union nut at the top of the gas valve Carefully pull off the connections to the spark electrode and separate the in line connector to the flame sensing electrode Refer to Fig 43 and 44 14 4 Component Cleaning Do not use a brush with metal bristles to clean...

Page 22: ...nsing Tubes 3 Flue Hood 4 Overheat Thermostat 5 Combustion Chamber 6 Combustion Chamber Fixing Screws 7 Gas Pipe Burner Assembly 8 Burner Assembly 9 Spark Electrode Assembly 10 Return Pipe 11 Flow Pipe 12 Flow Sensor 13 Heat Exchanger 14 Auto Air Vent 15 Combustion Sampling Point 16 Wing Nut 16 ...

Page 23: ...Hood 4 Overheat Thermostat 5 Combustion Chamber 6 Combustion Chamber Fixing Screws 7 Gas Pipe Burner Assembly 8 Burner Assembly 9 Spark Electrode Assembly 10 Flow Pipe 11 Flow Sensor 12 Heat Exchanger 13 Auto Air Vent 14 Combustion Sampling Point 10 Fig 42 Inner Casing 24SBi 14 ...

Page 24: ...e leads at the electrodes Loosen the screw and remove the electrode assembly Refer to Fig 44 15 4 3 Flame Sense Electrode Remove the inner casing and the combustion chamber Lower the f acia Separate the in line connector located in the controls compartment Remove the burner Refer to Section 15 4 4 Loosen the screw and remove the electrode assembly Refer to Fig 44 Ensure that the new electrode is a...

Page 25: ...move the casing bottom panel and disconnect the discharge pipe and pressure gauge sensor Refer to section 15 4 6 Withdraw the clip and withdraw at an angle the valve Refer to Fig 37 and 43 15 4 8 Diverter Valve if fitted Remove the cabinet front panel and lower the facia panel Drain the appliance as described in Section 15 3 preceding Disconnect the electrical connections Pull out the correct clip...

Page 26: ...ections and remove the heat exchanger 15 4 12 Pump Remove the cabinet front panel and lower the facia panel Drain the appliance as described in Section 15 3 preceding Release the water connections and remove the pump Refer to Fig 50 Disconnect and transfer the electrical connections to the new pump Set the pump speed to that of the replaced pump Do not forget to fit the gaskets at the connections ...

Page 27: ...he 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 Unscrew and remove the sensor Carefully position the replacement sensor so that the connections are away from the flue hood 15 4 18 Auto Air Vent Drain the appliance as described in Section 15 3 preceding ...

Page 28: ...812 1 87161428120 68 299352 24SBi Heat Exchanger Giannoni ref PR22 323 003 spec D2107 1 87161428000 117 15SBi Insulation Pack 1 77161922040 117 24SBi Insulation Pack 1 77161922040 75 E00 717 Auto Air Vent 38 in BSP Caleffi Mini Call 502030 1 87161405000 93 299 506 Pressure Gauge 4 Bar Dark Gray 1 87161423000 45 375 699 Pressure Relief valve Caleffi 312439 1 8716142 4040 36 E01 602 Pump c w Harness...

Page 29: ...29 M T W Th F S Su P DAY HR MIN ADV R I AUTO O RUN DHW CH Set 8 3 7 ...

Page 30: ...ng room stat calling Facia control knob above position I Fan ON Pump ON 20 second delay Reset on facia APS ON LOCKOUT all outputs OFF EXCEPT pump Gas valve and sparking ON Flame sense No flame sense for 8 seconds Burner ON This sequence is cycled to satisfy temperature set by facia control knob Temperature Sensor disconnected Fan and burner OFF Pump running Failed ignition Overheat of gas to water...

Page 31: ...ary electrical system checks are the first electrical checks to be carried out during a fault finding procedure On completion of the Service Fault finding task which has required the breaking and remaking of electrical connections check a EARTH CONTINUITY b SHORT CIRCUIT CHECK c POLARITY and d RESISTANCE TO EARTH Switch on the mains electrical supply Is the facia indicator illuminated Is there mai...

Page 32: ... of connection X5 Drop down the facia and expose the three PCB rear connectors Is there 230V at pins 3 4 of connector X11 centre connector Refer to above section Does the fan run and normal ignition take place BOILER DEMAND TEST No No No No No No No Yes Yes Yes Yes Yes Yes Yes Set the system to create a boiler demand Turn facia control knob to maximum Does the Fan run Press the facia reset button ...

Page 33: ... NOTE In the unlikely event of this not solving the problem Inspect the pressure pick up venturi in the fan Yes No Rectify flue problem Yes Is there continuity on the two green wires No Repair or replace harness Yes Replace control board Section 15 4 9 Yes Yes Boiler has LOCKED OUT probably due to overheating Is the boiler fully water pressurised and is all air vented Yes Switch off mains supply a...

Page 34: ... approx 210V DC across pins 1 4 of connector X3 during spark sequence Replace control board Section 15 4 9 No Yes Replace the gas valve Section 15 4 1 Does the flame continue for more than 10 seconds NOTE Reverse live neutral polarity will cause this fault And system should be cool No Switch off mains supply Remove boiler front panel and combustion chamber cover Is the sense electrode and lead in ...

Page 35: ...heck or replace room thermostat For Y plan system Replace control board For S plan system Replace DHW zone valve For Y plan system Replace mid position valve For S plan system Replace CH zone valve Complete systems outside the boiler are not the responsibility of Worcester Heat Systems But as a fault finding guide Check the IMPORTANT NOTES on Page 4 of the wiring guide booklet and use any propriet...

Page 36: ...old are subject to our official Conditions of Sale a copy of which may be obtained on application PUBLICATION 8 716 115 065a 05 08 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 manual is to be used in conjunction with the variant part number of the bar code bel...

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