Mitsubishi Electric aircon PA error code & blinking light

Use this Mitsubishi Electric PA guide to decide when to stop resetting, what to capture, and what to check before parts are quoted.

What does Mitsubishi Electric PA mean?

Mitsubishi Electric PA is listed as forced compressor error due to water leakage abnormality in Ceiling Cassette, Ceiling Concealed Ducted, Ceiling Suspended rows such as PLY-ZM / PLY-M cassette, PEY-M JAL ceiling-concealed ducted. The loaded row is source-backed by official diagnostic material. Confirm the exact model, series, or signal row before accepting a parts quote.

Blocked drain pipe, trap, or concealed drain route.
Float switch or drain-level protection triggered by water in the pan.
Drain pump, drain slope, or pan-level issue after clearing is attempted.

What to do now

Use these steps before running the unit again or approving drain or pump work.

Stop using the unit if PA returns
Stop using the unit if PA returns, water leaks, or the drain pan keeps filling.
Reset PA once
Capture the PA pattern, then stop the unit if water is leaking or the drain pan looks full. Power-cycle once only if the area is dry.
Send these to us
PA error code and blinking light, a clear display photo and blinking-light video if the unit shows one, Mitsubishi Electric model stickers, affected rooms, reset result, and where water appears

Source-specific guidance

These diagnostic-reference notes help match the code to the exact model. Electrical, refrigerant, wiring, resistance, and component checks are technician work, not DIY steps.

Source detail	What it says
Source repair action	Stop operation and check drain overflow or water-leak conditions before clearing the fault.
Singapore / model note	Official Mitsubishi Electric Singapore Mr Slim PDF page 3, Output pattern A. Use only for the listed PLY cassette, PEY ceiling-concealed ducted, and PCY ceiling-suspended indoor models; confirm the paired outdoor model before parts replacement.

What to check before repair

Use this split to separate safe evidence capture from the tests a technician should prove before quoting parts.

You can check	Technician should confirm
Before resetting PA, take a clear display photo and blinking-light video if the unit shows one.	Confirm whether PA is drain overflow, float switch, pump, or water-level protection.
Capture the Mitsubishi Electric indoor and outdoor model stickers so the correct family row is used.	Clear and flow-test the drain route, then check pan level and float operation.
Note whether one room, several rooms, or the whole system is affected, plus whether it returns after one reset.	Test pump power, pump discharge, and slope on cassette or concealed units.

What changes the next step

These clues decide whether the first check is room-side, shared outdoor-side, refrigerant-side, source-table, or model-family confirmation.

What you see	What it points to
Only one indoor unit shows PA.	The affected room, indoor board path, wiring route, or local component should be checked first.
Several rooms or the outdoor unit show the same PA fault.	The shared outdoor side, power path, communication trunk, or refrigerant circuit needs priority checking.
Water appears at the indoor unit or ceiling area.	Drain flow, float switch, pump, and pan level should be checked before running again.
The model family is different from the row you found online.	Use the model or series filter first; same-looking codes can still belong to different diagnostic tables.
The model belongs to Ceiling Cassette, Ceiling Concealed Ducted, Ceiling Suspended rows such as PLY-ZM / PLY-M cassette, PEY-M JAL ceiling-concealed ducted.	The loaded row is source-backed by official diagnostic material. Use the matching source row before quoting parts.

Drain clearing or pump decision

Mitsubishi Electric PA normally stays in repair scope: clear the drain, test the float or pump, and check slope before discussing replacement.

A blocked drain is usually a service-level repair if flow returns after clearing.
Pump or float-switch work needs part testing before replacement is approved.
Concealed drainage problems become labour-heavy because access decides the repair path.

Mitsubishi Electric PA questions

What does the Mitsubishi Electric PA error mean?

Can I fix a Mitsubishi Electric PA error myself?

No. PA needs a technician's measurement before parts are decided. Before resetting PA, take a clear display photo and blinking-light video if the unit shows one. Capture the Mitsubishi Electric indoor and outdoor model stickers so the correct family row is used.

Is it safe to keep running the aircon with a PA error?

Stop using the unit if PA returns, water leaks, or the drain pan keeps filling.

What causes a Mitsubishi Electric PA error?

Blocked drain pipe, trap, or concealed drain route. Float switch or drain-level protection triggered by water in the pan. Drain pump, drain slope, or pan-level issue after clearing is attempted.

Will a Mitsubishi Electric PA error need a repair or a full replacement?

Mitsubishi Electric PA normally stays in repair scope: clear the drain, test the float or pump, and check slope before discussing replacement.

What should I send a technician about a Mitsubishi Electric PA error?

Before booking, send: PA error code and blinking light, a clear display photo and blinking-light video if the unit shows one, Mitsubishi Electric model stickers, affected rooms, reset result, and where water appears.

Confirm the fault

Share the error code, model number and symptoms so we can assess the likely cause.

Not the right code?

Browse the full Mitsubishi Electric list or check a few codes in the same fault category.

Ready to get started?

Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.

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