Fan Coil Part Three: Understanding Your Fan Coil’s Actuator and Why It Might Be Stuck
If your condo feels too hot in the summer or too cold in the winter—even though the fan coil is running—you might be dealing with a stuck actuator. Here’s what that means and how to fix it.
What Is an Actuator in a Fan Coil System?
The actuator is a small but critical device that controls the opening and closing of the valve or cartridge inside your fan coil unit. This determines how much hot or cold water flows through the coil—and in turn, how warm or cool your air is.
What Happens When It’s Stuck Open?
If the actuator is stuck in the open position, the system constantly allows water to flow—whether it’s hot or cold. That can result in:
- Overheating in summer
- Unwanted cooling in winter
- Constant airflow that doesn’t match your thermostat settings
This issue typically signals:
- A malfunctioning actuator
- A faulty valve or cartridge
What’s the Fix?
An HVAC technician will:
- Inspect the actuator for failure
- Test the valve or cartridge
- Replace one, two, or all three components if needed
Can You Prevent It?
Yes—by scheduling annual fan coil maintenance, especially before your building switches from heating to cooling mode (or vice versa). Maintenance helps identify worn actuators before they fail.
Final Tip:
Never block your fan coil unit with furniture. Clear space = proper airflow = fewer breakdowns.