Bosch Appliances 18/25, 25/32kW, 12/18 535 SE/LD RDB Fault Finding, Control BOX Logic for

Page 48

47

FAULT FINDING

& DIAGRAMS

FAULT FINDING

Boiler not operating with a heating / hot water demand

Replace

control box

Yes

Replace

electrodes/

leads

No

Replace

control box

Yes

Eectrodes &

leads OK?

No

Unblock or

replace pipe

No

Replace

nozzle

Yes

Pipe to

nozzle

holder OK?

No

Reset air

setting

No

These fault finding charts are provided to locate and rectify faults. Whilst every given is correct and complete we covered. Worcester, Bosch Group cannot be deemed to be competent.

INSTALLATION &

Burner

 

Lockout

 

Lockout

Yes

Ignition

Yes

Pump

Yes

Nozzle

Yes

Combustion

Yes

Combustion

 

Reset

Yes

within 1

NO

after 12 sec

spark

produces

atomising

air setting

head set

No

combustion

motor runs?

 

 

 

 

second?

 

purge?

 

proved?

 

pressure?

 

fuel?

 

correct?

 

correctly?

 

head

No

 

 

 

No

 

 

 

No

 

 

 

 

 

Yes

 

 

to assist competent effort has been cannot guarantee held responsible

SERVICING INSTRUCTIONS

L & N to

control box?

Yes

Check boiler

No controls & supply

Motor gives

 

 

 

 

Replace

50 Volts on

 

 

No

 

 

 

 

 

 

motor

 

 

 

white wire?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

Purge

pressure 1-2 bar?

No

 

 

 

Solenoid operating?

Yes

 

 

Increase the pump

 

 

 

 

pressure, pressure OK?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No

Flame off &

re-lights?

Yes

No

Boiler or flue

blocked

and suitably taken to that every for costs incurred

FOR WORCESTER

Motor or

pump

seized?

No

 

 

Replace

Yes

 

 

motor/pump

 

 

 

 

Solenoid coil

functional

(100Ω)?

Yes

 

 

Replace

No

 

 

solenoid coil

 

 

 

 

Drive

coupling broken?

No

Solenoid coil

 

 

 

 

Coil lead

functional

 

 

Yes

 

 

 

 

 

 

 

OK?

(100Ω)?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

No

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Remove

burner

snorkle tube

&retest. Lights OK?

Yes

Reseal BF

qualified engineers ensure the information eventuality has by persons

GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32 8 716 113 389b (09/07)

Motor 40Ω

between blue &

black wires ?

Yes

Replace

control box

 

 

Replace

No

 

 

motor

 

 

 

 

Photo cell functional?

No

Replace

photo cell

 

 

 

Replace

 

Yes

 

 

 

control box

 

 

 

 

 

 

Oil to pump?

Yes

Replace oil

pump

Replace

Replace

pump stem

solenoid coil

valve,

 

 

 

 

pressure

 

 

 

 

OK?

 

 

 

 

 

 

 

 

 

 

 

 

 

No

 

 

 

 

 

 

 

Replace

 

 

control box

 

 

 

 

 

No

Photo cell functional?

No

Replace

photo cell

Yes

Replace

control box

been not

535 SE/LD RDB

FAULT FINDING

All resistance measurements are actual measured values and some variation is to be expected, therefore measured values should be similar to but not necessarily identical to the given values.

The operation of the photo cell can be tested by measuring the resistance across the photo cell, it should be a high resistance (greater than 10MΩ or open circuit) in the dark and low resistance (3kΩ or less) in light.

Burners on balanced flue systems can recirculate flue products resulting in the burner cycling, if this happens check the flue system integrity and the terminal position.

CONTROL BOX

LOGIC FOR

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Contents Greenstar Heatslave External 12/18, 18/25, 25/32kW Installation & Servicing Instructions Installation & Servicing InstructionsContents Safety Precautions Installation RegulationsSafety Precautions Installation Regulations OIL SMELLS, Leaks or Fumes from the ApplianceGeneral Information General InformationStandard Package Technical Data Technical DataDescription BSPLayout & Components Layout & ComponentsCleaning Primary Systems Cleaning Primary SystemsMains Supplies Mains SuppliesMains Water Expansion Vessel Electric SupplyOIL Supply OIL SupplyG J HeadWater Systems & Pipework Water Systems & PipeworkFilling Primary Sealed Systems SHOWERS/BIDETSDomestic HOT Water Condensate Pressure Relief Pipework Condensate Pressure Relief PipeworkCondensate Pipework Pressure Relief PipeworkBoiler Location Clearances Boiler LocationClearances FrontCabinet Mounted LOW Level Flue Terminal Positions Cabinet Mounted LOW Level Flue Terminal PositionsTerminal Position High Level Flue Terminal PositionsHigh Level Flue Terminal PositionsBalanced External Oilfit Flue Options Balanced External OilfitFlue Options AC DCabinet Mounted Balanced Horizontal Flue OptionsBalanced Flue Options Lifting and Carrying Precautions Unpacking the BoilerUnpacking the Boiler Safety Pipework & Flue PositionsPipework & Flue Positions Boiler Installation Boiler InstallationFlue Installation Flue InstallationInstallation Notes Combustion Chamber Combustion ChamberHor Plan sectional view Hook the retainer J over the end two bafflesPipework Connections Pipework ConnectionsWater Connections OIL Supply ConnectionsCondensate Connection Pressure Relief ConnectionOIL Burner & Pump OIL Burner & PumpOIL Burner OIL PumpRefitting Components Refitting ComponentsPlug burner lead E into control box F Mains Programmer External ElectricsBoard ElectricsBr Brown Blue Green/YellowRed WhitePRE-COMMISSIONING Checks Appliance PRE-COMMISSIONINGChecks Appliance Filling the System Filling the SystemStarting the Appliance Starting the ApplianceSafely dispose of the container/discharge Pressure adjustment Vacuum gauge port 25/32 Boiler lockout indicator onBleed & pressure gauge port Holder with oilBurner should be OFF and the circulating pump on Central heating Open all radiator valves Set the room thermostat to minimumWater Treatment Water TreatmentPump and all radiators Finishing Commissioning Finishing CommissioningAppliance Inspection and Service Inspection and ServiceRoutine servicing Loosen clip D to detach air ductClean the Burner 3.0mm Clean both sides of the fan impellerThoroughly clean any deposits Any debris and clean if necessaryFront 50 80EH 11.5 18.655 80EH 12.0 22.2Short Parts List 12/18 Short Parts List 12/18Auto reset High Limit thermostat Part Number 8 716 107 640 Burner SterlingShort Parts List 18/25 Short Parts List 18/25Manifold access cover seal Short Parts List 25/32 Short Parts List 25/32Fault Finding Fault FindingProblem Cause Remedy Faulty Boiler OperationNoisy operation Pump noise from air in pump or OIL SmellsNeutral N and the pin, wire or Base of the control box before replacing any componentsMeasure all 230V tests between 535 SE/LD RDB Fault Finding Control BOX Logic forSchematic ElectricalOIL Boiler Combustion Record Service 1 Date General checks Excellence Comes AS Standard

25/32kW, 12/18, 18/25 specifications

Bosch Appliances has carved out a reputation for engineering high-performance heating solutions, particularly with their range of heating systems including the 18/25, 12/18, and 25/32 kW models. These systems are designed to meet the diverse needs of residential and commercial spaces while maintaining energy efficiency and sustainability.

The Bosch 18/25 kW model excels in providing an optimal heating solution for medium to large residential properties. It is equipped with a highly efficient condensing boiler that extracts additional heat from flue gases, achieving significant energy savings. The built-in, user-friendly interface allows for easy programming and monitoring, which maximizes user convenience.

The 12/18 kW model provides a versatile opportunity for smaller homes or apartments. Its compact design ensures that it fits seamlessly into tighter spaces without sacrificing performance. The unit operates quietly, making it an excellent choice for residential areas where noise can be a concern. Additionally, it features the latest modulation technology, optimizing energy usage and maintaining consistent temperatures.

Finally, the 25/32 kW model is ideal for larger installations, offering robust performance even in high-demand scenarios. This model benefits from advanced heating management systems that enable intelligent control of heating zones, ensuring efficiency and comfort throughout the property. With its enhanced energy rating, the 25/32 kW model significantly reduces the carbon footprint, aligning with modern sustainability goals.

Across the board, Bosch Appliances integrates advanced technologies such as intelligent diagnostics, smart home compatibility, and eco-friendly materials. All models are constructed with durability in mind, featuring corrosion-resistant heat exchangers and high-quality components designed for longevity.

The customer-focused features, including comprehensive warranty packages and responsive customer service, further exemplify Bosch's commitment to quality. Overall, Bosch Appliances 18/25, 12/18, and 25/32 kW heating systems stand out for their innovative technology, efficient performance, and reliability, making them an excellent choice for those looking to upgrade their heating solutions.
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