P6 Coil freeze or overheat protection

What the control is telling you

Cooling: the indoor coil stayed below -15°C for 3 minutes after the compressor started, twice within 16 minutes. Heating: the coil went above 70°C, twice within 10 minutes. The unit pauses 6 minutes after the first event and locks out with P6 on the second.

Applies to: PEAD-RP35/50/60/71/100/125/140JA and JA(L) ducted indoor units (220-240 V models)

Likely causes

• Dirty filter or low airflow
• Supply air short-cycling back to the return
• Running outside the allowed temperature range (very cold in cooling, very hot in heating)
• Indoor fan motor or its board drive faulty
• Outdoor fan not controlled properly
• Refrigerant overcharge
• Restriction in the refrigerant circuit
• Heating only: outdoor unit bypass circuit faulty

Test and repair steps

1. Check and clean or replace the filter and look for closed or blocked registers.
2. Look for supply air being drawn straight back into the return and remove the cause.
3. Confirm the indoor fan runs at the right speed (see the DC fan motor check in the manual, section 10-8).
4. Check that the outdoor fan runs.
5. Check the refrigerant charge and look for restrictions with gauges.
6. After the repair, cycle the power and run the unit to confirm the code does not come back.

Models that show this code

14 models in Mr. Slim PEAD-RP JA(L) ducted indoor unit

Other codes on the same units

• P1 Room (intake) air sensor TH1 open or shorted
• P2 Liquid pipe sensor TH2 open or shorted
• P4 Drain float switch disconnected
• P5 Drain overflow - float switch wet with pump running
• P8 Pipe temperature out of range (coil not cooling or heating)
• P9 Coil sensor TH5 open or shorted
• Fb Indoor control board memory error
• PA Water leak detected