Worcester 28i Junior Specifikace

This booklet is accurate at the date of printing but will be superseded and should be disregarded if specifications and/or appearances are changed in

Note: This fault-finding information is for guidance only. Worcester Heat Systems cannot be held responsible for costs incurred bypersons not deemed t

Commence normalcentral heating modeuntil temperaturereaches 20°C34There is a delay of 6 seconds, pump pulses for 2 seconds,60 second wait,2 second pum

Roomthermostatand/or mainsprogrammer(or link) Onfaciaprogrammer(if fitted) OnCH controlknob On3318. Operational Flow DiagramsMAIN SWITCHONCENTRALHEATI

321 - 23-49102812 -1314 -151619201118248527671725-2621-23NOTE: READ THIS SECTION FULLY BEFORE COMMENCING THEINSTALLATION.11.1 GeneralThe appliance is

1 H05-333 Burner 24 NG 1 8 716 105 484 02 H05-352 Burner 28 NG 1 8 716 105 485 03 H05-337 Gas Valve NG 1 8 716 105 654 04 H05-338 Gas Valve LPG 1 8 71

20 Auto Air VentRemove the complete pump assembly as described in Section16.18. Take care not to strain the electrical connections.Pull out the clip s

15 Primary [ch] SensorRemove the clip-on facia cover and the cabinet. Lower the faciaonto the support lugs.Carefully pull-off the connections. Release

9 Inlet Water Filter and Flow Restrictor Remove the flow turbine as described in 16.8 preceding.Taking care, remove flow restrictor assembly from the

5 Combustion Chamber Insulation. Remove inner casing door and combustion chamber cover.Slide the damaged insulation panel from the applianceRear Remov

2 Spark ElectrodeRemove the inner casing cover and the combustion chamber cover.Carefully pull off the lead from the electrode. Unscrew the screwand r

4320. Conversion InstructionsNOMINAL BOILER RATINGS (10 Minutes After Lighting)BOILER ADJUSTED FOR G20 (Natural Gas)OUTPUT INPUT (Net) GAS RA

IMPORTANT: Turn off the gas supply and electrically isolatethe appliance before replacing any components.NOTE: Turning the control knob fully anti-clo

Inner Case Cover Unscrew the two screws and lift off. Refer to Fig. 39.Combustion Chamber Cover Unscrew the two screws, lift andpull forward to remov

23Fig. 41. Inner case components1. Flue hood 2. Overheat thermostat3. Burner4. Combustion chamber cover5. Spark electrode assembly6. Heat

42Boiler is running in“Autofrost stat” mode.See Section 17.Replace control board.Note: A damp boardcould cause this fault.Is the boiler in a verycold

41Replace control board.In the unlikely eventof this not solving theproblem replace codeplug.Pressure switch hasopened duringoperation.Check flue forb

40Remove multiwayconnector from boardposition ST16. Testresistance across pins16 and 17 ( yellowwire). Is it between 1kOhm and 30 kOhm?Test resistance

39Remove combustionchamber cover.Is the sense electrodeand lead in goodcondition and is gapcorrect?Replace flame sensoror wiring.NoNoRemove multiwayco

38NoNoReset and restart theboiler in CH mode.Does the pump run?Test resistance acrosspins 4 and 5(blue wires). Is resistance between10Ω and 25Ω ?Repai

37Re-connect the 3-wayconnector and open atap to run the turbine.Is there between 1.5Vand 4.5V across thegreen and blackwires/terminals?Is there conti

36Is there a 230V AC livesupply acrossTerminal ST2 pins Land N?Switch off electricalpower.Has fuse F1 blown?Replace fuse andinvestigate cause.Suggesti