mitsubishi mr slim P6 error

[symon22]

hi chaps,
i have a re-occuring error code p6 on a mitsi mr slim unit .

have followed the mitsi fault code sheets and have found no fault.

the unit checks out fine in all modes of operation and works fine for a period of time then fails with the same problem.

have any of you any pointers ,or have come across this before,

any input would be greatful

thanks..

[p_p]

I have come across this before and allways found it to be refrigerant charge problem.

Regards

PP

[Thermatech]

Mr Slim A control R407c & R410a systems.
P6 = indoor coil frost protection in cooling or indoor coil overheat protection in heating.

Cooling
One of the 2 indoor coil sensors reads minus 15 deg C for 3 mins.
Heating
One of the indoor coil sensors reads over 70 deg C.

If you are sure the refrigerant charge is correct & system operation is correct then it could be a coil temperature sensor reading wrong temperature.
If you have one of those little monitor things which plug into the outdoor circuit board you can monitor the indoor coil temperature.
On later type remote controllers you can get all operating data like temp sensor data but you will need a service manual to do this.
Or you can measure the ohms resistance of the temp sensors & compare with the chart in the service manual.