SR22 pilot reported diverting to a nearby airport after noting a co level high aural alarm.

Narrative:

While climbing out I experienced a visible red alert on the panel accompanied by an aural alarm indicating co level high. Without having experienced this alarm previously I was unsure of the severity of the alert so after consulting the emergency procedure in the manual which stated 'land as soon as possible' if the alert did not extinguish I informed departure of my intent to make an expedited landing straight ahead on the runway I had in sight. This runway was at a restricted air reserve base but it was directly ahead; large and unobstructed. Given that a potential consequence of high co is loss of consciousness or fire (from exhaust leak) I decided to proceed with an expedited landing and troubleshoot on the ground. After arranging access to the base for some local mechanics; their examination cleared me of the risk of significant threat of co poisoning and I departed the base and continued on an uneventful flight home after stopping at another nearby airport for additional fuel because of the second climb out. It was later determined that a contributing factor to the alarm was likely to have been the recirculation setting on the aircrafts air conditioning system during climb out (on; instead of the proper off setting per the checklist).

Original NASA ASRS Text

Title: SR22 pilot reported diverting to a nearby airport after noting a CO LEVEL HIGH aural alarm.

Narrative: While climbing out I experienced a visible red alert on the panel accompanied by an aural alarm indicating CO LEVEL HIGH. Without having experienced this alarm previously I was unsure of the severity of the alert so after consulting the emergency procedure in the manual which stated 'land as soon as possible' if the alert did not extinguish I informed Departure of my intent to make an expedited landing straight ahead on the runway I had in sight. This runway was at a restricted Air Reserve Base but it was directly ahead; large and unobstructed. Given that a potential consequence of high CO is loss of consciousness or fire (from exhaust leak) I decided to proceed with an expedited landing and troubleshoot on the ground. After arranging access to the base for some local mechanics; their examination cleared me of the risk of significant threat of CO poisoning and I departed the base and continued on an uneventful flight home after stopping at another nearby airport for additional fuel because of the second climb out. It was later determined that a contributing factor to the alarm was likely to have been the recirculation setting on the aircrafts air conditioning system during climb out (on; instead of the proper off setting per the checklist).

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1750691
Time
Date	202007
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	SR22
Operating Under FAR Part	Part 91
Flight Phase	Initial Climb
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning Distribution System
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 14 Flight Crew Total 1870 Flight Crew Type 138
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy