Thermal runaway error on the Prusa MK4

Source: ProductDB enrichment catalog Confidence: 85% Verified Aug 8, 2026

The printer reports a thermal runaway and shuts down to prevent a fire risk. The thermistor or heater may be faulty.

How to fix Thermal runaway error

Check the thermistor

Inspect the thermistor wiring and reseat it in the hotend. Replace if damaged.

Source: ProductDB enrichment catalog Confidence: 80% Verified Aug 8, 2026

Difficulty: ★★★ Est. 20 min

Verify the heater cartridge

Check the heater cartridge is seated and not shorting. Replace if faulty.

Source: ProductDB enrichment catalog Confidence: 80% Verified Aug 8, 2026

Difficulty: ★★★ Est. 20 min

Replacement parts for the Prusa MK4

Prusa MK4 Nozzle Prusa MK4 Hardened Steel Nozzle Prusa MK4 PLA Filament Prusa MK4 Build Plate Prusa MK4 Hotend Assembly Prusa MK4 Magnetic Bed Sheet Prusa MK4 PTFE Tube Prusa MK4 Nozzle Set

← All Prusa MK4 error codes

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