FAULT FINDING LOGIC FOR
535 SE/LD RDB CONTROL BOX
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.
These fault finding charts are provided to assist competent and suitably qualified engineers
to locate and rectify faults. Whilst every effort has been taken to ensure the information
given is correct and complete we cannot guarantee that every eventuality has been
covered.
Worcester, Bosch Group cannot be held responsible for costs incurred by persons not
deemed to be competent.
FAULT FINDING
& DIAGRAMS
FAULT FINDING
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32
8 716 113 389b (09/07)
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