HVACopediaMitsubishi · Heat pump
PA Water leak detected
What the control is telling you
Checked whenever the unit is not cooling or drying. Set when the liquid pipe stays more than 10°C below the intake air for 30 minutes and the float switch has been wet for 15 minutes. Does not clear until the main power is reset. Some controllers show this as 2500.
Applies to: PEAD-RP35/50/60/71/100/125/140JA and JA(L) ducted indoor units (220-240 V models)
Likely causes
- On multi-unit systems: line sets crossed between units
- On multi-unit systems: indoor/outdoor wires crossed
- Intake or liquid pipe sensor reading wrong
- Drain pump not working
- Drain pump or drain line clogged
- Float switch stuck wet or connector loose
Test and repair steps
- Check the line sets and S1-S2-S3 wiring go to matching units.
- Compare room and liquid pipe temperatures on the remote (see P2).
- Check that the drain pump runs and clear the pan and drain line.
- Check the float switch and its connector (see P4 and P5).
- Reset the main power after the repair - PA does not clear on its own.
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Source: Mitsubishi Electric PEAD-RP35-140JA(L) Service Manual, 10-3 Self-diagnosis action table, p.34. Summarized in our own words; check the original manual for your model.
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