October 8, 2025

Mitsubishi Error Code 2502: Drain Pump Fault

Mitsubishi error code 2502 means the indoor-unit drain pump failed to remove condensate water, triggering the float switch safety. Typical causes: clogged drain line (40 %), failed pump motor (30 %), or blocked float sensor (20 %). The unit stops cooling to prevent overflow and water damage. Average repair cost: $250 – $550; pump replacement up to $800. Fixair’s HVAC technicians clear clogs and replace drain pumps the same day to restore safe operation.

Quick Answer — Mitsubishi Error Code 2502

Error code 2502 appears when the indoor-unit drain pump fails to remove condensate water, causing the float switch to trip.

Main causes include clogged drain pipe (40 %), pump motor failure (30 %), and stuck float switch (20 %).

The system shuts off to prevent water overflow and ceiling damage.

Power off the unit, check the drain line for blockages, and verify that the pump runs freely.

Typical repair cost: $250 – $550; complete pump replacement $700 – $800.

Most cases are cleared within 2 hours by Fixair technicians.

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What 2502 Means

Error 2502 is a drain-pump safety shutdown. When the float switch detects water level above the limit, the controller stops indoor operation and flashes code 2502.

If the fault is ignored, water can overflow from the tray, causing property damage and mold growth.

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Main Causes of 2502

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  1. Clogged Drain Line (≈ 40 %) — Slime or dust blocks water flow.
  2. Failed Pump Motor (≈ 30 %) — Pump impeller jammed or motor burned out.
  3. Float Switch Stuck (≈ 20 %) — Debris or scale prevents float from moving.
  4. Wiring Issue (≈ 10 %) — Loose connector between pump and PCB.

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Immediate Safety Steps

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  1. Shut off power to the indoor unit.
  2. Remove and clean the drain tray and pump assembly.
  3. Flush the drain pipe with warm water or compressed air.
  4. Manually lift the float to check for free movement.
  5. If the pump does not run when energized, call Fixair for replacement.

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Repair Costs and Timeframes (2025)

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  • Drain line cleaning — $250 – $350 (1–2 h)
  • Pump motor replacement — $400 – $600 (2–3 h)
  • Full assembly replacement — $700 – $800 (3 h)
  • Most repairs are completed same-day, including functional testing and leak check.

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Prevention Tips

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  • Flush the drain line every 3–6 months.
  • Install an algaecide tablet in the tray during cooling season.
  • Keep filters clean to reduce condensate debris.
  • Schedule Fixair maintenance to inspect the float and pump annually.

Routine maintenance prevents ≈ 90 % of drain pump faults.

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Frequently Asked Questions

Is error 2502 dangerous?

Not electrically, but it can cause water overflow and ceiling damage if ignored.

Can I fix it myself?

You can clean the drain line and tray, but electrical testing of the pump should be done by a technician.

How much does it cost to repair?

$250 – $550 for cleaning or motor repair; $700 – $800 for pump replacement.

How long does it take?

1 – 3 hours depending on access and component replacement.

Will it come back?

Not if the drain line is kept clear and the pump is tested each season.

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Summary

Error code 2502 indicates a drain-pump fault in Mitsubishi indoor units. The unit shuts down to prevent water overflow.

Clean the drain system and verify pump operation before restart.

Most repairs cost under $600 and are completed within a few hours.

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