Resmed CPAP Error 4 Error Code

Updated 2026-08-29 · review status: manual-verified Last verified: 2026-08-29

Quick answer

Main PCB over temperature / Motor over temperature (Triptych blower only); hot environment, blocked filter, blocked tubing or water in tubing - allow to cool, replace filter, power-cycle

Severity: high · DIY difficulty: intermediate

Safety

TBD - must be written per-code before publish

What Error 4 means

Main PCB over temperature / Motor over temperature (Triptych blower only); hot environment, blocked filter, blocked tubing or water in tubing - allow to cool, replace filter, power-cycle

Code meaning varies by series

  • AirSense 11 - service and technical guide doc 398011/2 (manufacturer): Main PCB over temperature / Motor over temperature (Triptych blower only); hot environment, blocked filter, blocked tubing or water in tubing - allow to cool, replace filter, power-cycle
  • AirSense 11 - ResMed official user guide: Device may have been left in a hot environment (allow to cool), air filter may be blocked (replace filter), or water may be in the air tubing. Disconnect then reconnect the AC adaptor to restart the device.

Causes, ranked

  1. Causes not yet documented — verify against the service manual.

Parts & supplies for Resmed CPAP: filters, control boards, sensors, and common replacement parts.

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Sources

  • ResMed AirSense 11 Series Service and Technical Guide (doc 398011/2), Troubleshooting guide - numbered error messages — verified 2026-08-29
  • ResMed AirSense 11 User Guide (Americas, official): Error 4 = hot environment/blocked filter/water in tubing - cool, replace filter, power-cycle; all other numbered Errors = unrecoverable device fault, contact care provider, do not open — verified 2026-08-29