I have H72 error on my LA-MI heat pump. What does this mean?

Applicable to models:  LA6MI, LA9MI, LA12MI, LA16MI


Issue:  Error code H72 shown on the display.


What this means: H72 error is due to the hot water tank temperature sensor misreading

It will not be possible for the heat pump to heat the hot water tank whilst this error is present, as the heat pump cannot tell how if the hot water tank is up to temperature or not. 

Action: Engineer will need to investigate by following the flow diagram below.
Heat pump must be safely isolated from mains supply before carrying out any work! 

The temperature sensor is an NTC-2, which means it has a reisistance of 2.0 kOhm at 25C.
The resistance can be checked whilst the probe is exposed to a known temperarture.

Malfunction Decision Conditions:

When tank connection is set to ON, the temperatures detected by the tank temperature sensor are used to

determine sensor error.

Malfunction Caused:

1 Faulty connector connection.

2 Faulty NTC-2 sensor.

3 Faulty Main Water PCB.

Abnormality Judgment:

Continue for 5 seconds.



Possible parts, depending on engineer diagnosis: 

• Temperature probe for Hot Water NTC-2 (applies to all models), part : X-029379

• Main Water PCB aka "Indoor 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


Was this article helpful?

That’s Great!

Thank you for your feedback

Sorry! We couldn't be helpful

Thank you for your feedback

Let us know how can we improve this article!

Select atleast one of the reasons
CAPTCHA verification is required.

Feedback sent

We appreciate your effort and will try to fix the article