How to troubleshoot "The instrument encountered a thermal coolant error" on the NovaSeq X/X Plus

Error message: "Critical System Error: The instrument encountered a thermal coolant error. Please shutdown the instrument and contact Illumina Technical Support".

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Troubleshooting steps:

1. Contrary to the error statement, do not immediately power cycle the instrument.

2. Collect the following Logs depending on error context:

   1. If during a sequencing run, collect the Logs.zip file from /usr/local/illumina/runs/[RunID]/Logs

   2. If during initialization or instrument idle, collect the novaseq-x-series-control-software folder in the /usr/local/illumina/logs directory.

3. Contact Illumina Tech Support for next steps to troubleshoot this issue.

For any feedback or questions regarding this article (Illumina Knowledge Article #8271), contact Illumina Technical Support [e-mail].