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I Have a Bad HVAC Actuator

Tyler Lacoma

HVAC — heating, venting and air conditioning — refers to a bundle of systems that perform different duties to heat or cool spaces. Complex HVAC systems are used in houses, while simple versions are found in cars. Divide the system down into base components and you may find a number of small actuators, basic electrical components designed to turn electrical signals into basic force. If these actuators fail, they need to be replaced to restore efficiency to your system.

HVAC Actuator Jobs

HVAC actuators control solenoids, valves, fans and many other parts of HVAC systems, depending on the design. Most frequently, they are associated with vents and vent control. Actuators open or close vents for the system so air flow can be created for either warming or cooling. This is seen most on smaller HVAC systems, rather than large residential versions, which have permanently open vents for more precise control.


Symptoms of bad actuators can be a variety of nonresponsive systems. Fans that won't turn, valves that will not open to let refrigerant through, motors that will not open are all potential signs of actuator issues. However, for the common vent actuator, a noticeable sign is lack of air flow, even when the HVAC system is turned on and working correctly. Examination of the vent or testing of the wiring can narrow the issue to a failed actuator.


Because actuators are such simple components, the best way to fix the problem is to replace them entirely. This means buying a new valve, solenoid or other part of the system and installing it, removing the old part entirely. This may require professional work, which also gives you the ability to be more sure of the actuator causing the trouble. The repair professional should be able to test the system thoroughly and inspect actuators for performance issues.

Other Solutions

If the actuator appears to have failed but is actually undamaged, the problem may lie in other components your system uses. For example, many heating systems only activate the actuators when a certain temperature is reached. If the sensors have failed, the signal may never come to the actuator, keeping the vents closed. Replacing thermistors or wiring may be the real solution to your problem.