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MRCOOL / DIY 5th Generation

MRCOOL PC 10 error code

PC 10 means outdoor low AC voltage protection from the outdoor voltage detection circuit. The manual trigger fits the inverter, voltage, or compressor-drive category.

Urgency
advisory
Verified
Jul 18, 2026
Fix path
Technician

What it means

PC 10 means outdoor low AC voltage protection from the outdoor voltage detection circuit. The manual trigger fits the inverter, voltage, or compressor-drive category.

Urgency

advisory

Treat it as a service call if it returns after one reset; do not open the outdoor cabinet.

Likely causes

  1. Brief power event, brownout, or unstable supply voltage
  2. Loose power connection, reactor, or outdoor electrical component problem
  3. Inverter/IPM protection or current-detection fault
  4. Compressor winding, drive, or outdoor board fault after power checks pass

Homeowner fix

Turn the system off for 2 minutes, note any storm, brownout, generator, or breaker event, then restore power once if the breaker is stable. If the code returns, write down the exact display and stop there.

When to call a pro

Call a licensed HVAC technician if PC 10 remains or returns. Tell them the manual trigger is "Outdoor low AC voltage protection from the outdoor voltage detection circuit" and point them to 4.3 Error Display; 4.7 TS10-S.

This code points to electrical or inverter work - get repair quotes from contractors in your area.

Get repair quotes

Repair vs replace

Inverter, IPM, compressor-drive, and voltage faults can become expensive. A power correction is usually repairable; confirmed compressor, IPM, or major outdoor board failure on an older unit should be priced against replacement.

See MRCOOL mini-splits

Your MRCOOL model

DIY 5th Generation model pages in the MRCOOL catalog help compare this repair path with current replacement options.

Parts for this line

The parts catalog for MRCOOL DIY 5th Generation lists 10 sourced replacement parts for this product line.

Open parts page

For your technician

Technician note: follow 4.3 Error Display; 4.7 TS10-S. The sourced steps start with Check the power supply; if it is not working, turn off the unit. Page context: MRCOOL maps this display to the DIY 5th Generation line; source: MRCOOL R454B DIY-5 service manual.

Which systems show it

  • MRCOOL DIY 5th Generation single-zone 9k, 12k, 18k, 24k, and 36k D25 indoor/outdoor models listed in manual section 1.1.

Related troubleshooting

Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.

Manual trigger

Outdoor low AC voltage protection from the outdoor voltage detection circuit.

Related codes

Source

MRCOOL R454B DIY-5 service manual
Section
4.3 Error Display; 4.7 TS10-S
Page
37, 71

Short quote: "PC 10 ODU Low AC Voltage Protection TS10-S."

Sourced Jul 2026

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