A5 Daikin — Damper actuator stuck
At a glance
- Severity
- WARNING
- Domain
- air_handling_unit
- Reference standard
- UNI EN 13053, UNI EN 1751, ASHRAE 90.1
- Product / context
- Freeze-up protection
What it means
An AHU damper actuator (outdoor air, recirculation air, mixing, or free-cooling damper) is stuck in one position and does not respond to the command. This compromises airflow control and thermo-hygrometric conditions. If the outdoor air damper is stuck open in winter, there is a risk of coil freezing.
Probable causes
- Electric actuator with burned motor or broken gears
- Damper mechanically stuck due to corrosion or debris
- Actuator wiring broken or connector disconnected
- Command signal from controller absent
- Actuator return spring broken (for spring-return actuators)
Where to start
Check the damper position visually. Try to move it manually (with actuator disconnected). If mechanically stuck, look for corrosion or debris. If it moves freely, the problem is in the actuator.
Full guided diagnosis in the app
The diagnostic tree for this fault has 5 guided steps with measurements, checks and resolutions. You'll find it in HVACIQ, one of the four IndexOS apps: free, works offline.
Printable sheet + Daikin updates
Leave your email: get the link to the printable Daikin error-code sheet and a heads-up when we add new codes and guides.
Double opt-in, zero spam, one-click unsubscribe.