Manuals / Bosch Appliances / Household Appliance / Boiler

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

Models: 25/32kW 12/18 18/25

1 52
Download 52 pages 48.17 Kb
Page 48
Image 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

Page 47 Page 49
Page 48
Image 48
Bosch Appliances 18/25, 25/32kW, 12/18 instruction manual 535 SE/LD RDB Fault Finding, Control BOX Logic for
Page 47 Page 49

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.