Short circuit: (dead test)
This test will ascertain the integrity of the internal resistance of the boiler and should read no resistance/infinity between L and N on the 3 amp fused plug top pins.
- Set multimeter on ohms scale for resistance readings
- First put black lead from multi meter to N pin on the boiler terminal strip and secondly put the red lead from the multi meter to the L pin on the boiler terminal strip
There are six internal boiler components to check and the L and N connections for each component must be removed individually and then the L and N at the 3 pin plug top or at the boiler terminal block must be measured again.
Components to check (in this sequence):
Should the internal resistance measure infinity/no resistance when the component is disconnected, then the faulty component has been traced.
Should the resistance reading maintain moving when the component is disconnected, the dead short is elsewhere (further investigation needed in the above sequence).
As a member check out these Key Areas
- Sequence of boiler operation
- Boiler servicing procedures
- Boiler System Component Testing
- Top Tips for the Heating Engineer
- Boiler Manuals and Service Manuals
- General Boiler Fault Finding
- Boiler Error Codes
- Using Multimeters to diagnose Boiler Faults