A Class Heat Pump displaying 'Bus Initialising' on the user interface, what does this mean?

Modified on Wed, 3 Apr at 3:00 PM

'Bus Initialising' occurs when the indoor wiring centre is unable to find the outdoor unit on the communication network. This can be due to a few different causes and may require an engineer to investigate. Possible causes include:

  • Corruption of the SD card fitted to the wiring centre (water module) - powering off the unit, removing the SD card and powering the system back up may resolve this.
  • Power loss to the outdoor unit - It is worth checking the outdoor rotary isolation switch, and circuit breakers are not in the off positions
  • A loose connection or break in the Modbus communication cabling - This will need testing by an engineer
  • An issue with one of the 4 components connected to the Modbus network (SEC board, Master board, Water module and User interface) - This will require investigation by an engineer.


This is not covered under the manufactures guarantee.



Please find a list of approved Dimplex service agents via the below link..

https://glendimplexservice.freshdesk.com/support/solutions/articles/79000136231-looking-for-a-service-engineer-to-repair-my-out-of-guarantee-product-


Note: From software 1.17, this message will appear as 'Network Refreshing'.



Applicable Models:

A6M, A8M, A12M, A16M

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