I have H12 error on my LA-MI heat pump. What does this mean?

Modified on Wed, 22 Feb, 2023 at 10:00 AM

Applicable to models:  LA6MI, LA9MI, LA12MI, LA16MI


Issue:  Error code H12 shown on the display. The heat pump will not run.


What this means:  Mismatch of PCB fitted to the heat pump (ie a 6kW board fitted alongside a 9kW board). Only likely to occur if an engineer has visited recently and accidentally fitted the wrong PCB for a different kW model of LA-MI heat pump.


Action: Engineer visit will be required to fit the correct kW size of PCB (fridge or water PCB) so that the heat pump has matching kW boards on both water PCB & fridge PCB.  

Possible parts, depending on engineer diagnosis:

• Main Refrigerant PCB (part number depends on model of heat pump)
LA6MI part: X-2511024
LA9MI part: X-2511038
LA12MI part: X-2511044
LA16MI part: X-2511057

• Main Water PCB (part number depends on model of heat pump)

LA6MI part: X-2511031
LA9MI part: X-2511039
LA12MI part: X-2511051
LA16MI part: X-2511058

Require additional help? Please follow link below


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