How To Fix It

How to Adjust HVAC Automatic Dampers?

The main advantage of automatic dampers is the fact that you might not have to ever manually change their position. But you may have to override the damper if it ever goes bad or adjusts the angle of the damper’s plate.

To manually open an automatic damper, you’d have to disconnect the motor from the shaft. With adjustable automatic dampers, you can change the position of the damper plate to make it less open or less closed – simply detach the spring, loosen the screw, and rotate the plate. 

How to Adjust HVAC Automatic Dampers?

Typically, the motor inside the damper will start rotating the element until a certain position is reached. In adjustable automatic dampers, you are able to customize this position.

To make the damper more open or more closed when power is applied, change the plate position. To change the initial or final position of the damper plate, you would have to:

  1. Detach the element’s spring from the motor bracket.
  2. Loosen the screw.
  3. Rotate the plate to the intended position.
  4. Tighten the screw once the outer ring is seated on the inner ring.
  5. Reattach the spring.

How Do I Manually Open My HVAC Damper?

If you have manual dampers, then all you would have to do is turn the lever in the right direction. In the absolute majority of cases, automatic dampers cannot be manually opened unless the component gets fully detached

Read: Why HVAC Zone Damper Not Working? Troubleshooting Guide

How Are Motorized Dampers Controlled?

Actuators are the parts of the damper that control the movement of the adjustable louvers and blades

These elements can be customized for specific systems. Usually, you’ll either have an actuator that will close when power is applied to it and then open up with the help of a spring or vice versa.

How Does a Motorized HVAC Damper Work?

Dampers can sometimes get confused with vents, but these components are not the same. 

The main difference is that HVAC dampers can be placed at any point between fully closed and fully open thanks to actuators that utilize a low-voltage signal

Read: Honeywell Humidifier Damper Position On Winter/Summer

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How Do You Adjust Dampers for Winter?

During the colder time of the year, what you would want to do is force more air onto the floor (or the area) that gets used the most. As heat naturally rises, you should adjust the dampers in such a way, so that less air gets to travel upstairs and more – downstairs.

Before changing the position of the dampers, however, you would have to figure out what damper controls what zone and label the components.

  1. You’ll need a permanent marker and a family member who is going to be helping you.
  2. Open all the registers around the house and switch the fan setting to ‘on’.
  3. Choose one damper that you want to start with, close it, and ask your assistant to check where in the house the airflow got affected.
  4. Using the marker, label each damper with the area that it’s responsible for.
  5. In winter, simply adjust the dampers on the first floor to be open as the warmed air is going to rise to the second floor anyway.

How Do I Know If My Automatic Damper Is Open?

It is relatively easy to figure out whether the dampers are opened or closed if you have manual dampers. Simply take a look at the level – if it’s parallel to the duct, then the damper is open.

When it comes to automatic dampers, the only way to check if the elements are open is to stand next to the air register and take note of the airflow. If you can feel air coming out, then the damper is open.

Some automatic dampers also have a gauge on the motor to tell if the element is open or closed.

Read: What Are 4 Basic Categories Of HVAC Systems?

How to Locate Dampers in Ductwork?

The easiest way to find a manual damper is to look for a lever on the ducts – the damper would be located right under the metal level, inside the ductwork.

Typically, HVAC dampers are located in the main trunk line. Search before and after the major junctions.

In multiple system ducts, the dampers can be usually found on every main line.

Is It OK to Close HVAC Dampers?

HVAC dampers can be either open or closed, depending on what exactly you want your house temperature to be like. In a multi-zone system, you can easily adjust the temperature in your home by simply closing or opening the dampers that are responsible for certain areas.

Keeping the dampers closed in a properly installed multi-zone system with two-stage HVAC equipment will not cause any damage to the equipment as the extra air will get distributed.

Read: What Are Zoned HVAC Systems?

How Do You Override a Damper?

In some cases, you might be able to disconnect the motor from the shaft and then manually open the damper. There are also motors with a manual release button; you can push it and turn the shaft by hand.

In any case, you should switch the power to the element off before attempting to override the damper.

Read: What Are Zoned HVAC System Problems?


How Do You Balance HVAC Dampers?

  1. If you live in a two-story building, you would want to close the upstairs dampers in the winter to balance out the temperature.
  2. You can also try to program the upstairs thermostat to 2 degrees higher than the downstairs thermostat.
  3. Turn the fan setting to ‘on’, so that the HVAC system gets to work its magic.

What Is an Automatic Damper?

Unlike manual dampers, automatic dampers have a small motor that can open or close the damping valves and plates

Such automatic systems can be controlled remotely and, in an ideal case scenario, you would never have to think about manually changing your dampers position as the system is going to do that for you.

What Sets the Damper Position?

Manual dampers have special levers or handlers that can be used to manually set the damper’s position. In an automatic damper, the thing that changes the element’s position is the damper motor and the actuators.

How Do You Tell If an HVAC Damper Is Working?

Usually, all you would have to do is turn your HVAC system on and check for airflow at the air registers. If there is no air coming from the vents, you can try opening the damper, and if there is still no airflow, then the damper might have gone bad.

How Do You Balance Upstairs and Downstairs Temperature?

Keeping the upstairs dampers in a closed position during winter can help balance out the temperature throughout the house.

You should also not forget to turn the fan setting to ‘on’ and if you have any ceiling fans – use the things strategically. In the summer, for example, the fan direction should be counterclockwise (to create a downdraft).

What Are the 3 Types of Dampers?

There are plenty of different variations of dampers:

  • Butterfly flat dish dampers
  • Blade dampers
  • Guillotine dampers
  • Louver dampers
  • Inlet vane dampers

Should HVAC Damper Be Open or Closed?

In a multi-zone system, the position of the dampers will depend on what room you want to heat or cool. However, it is generally recommended to keep the dampers responsible for the upper floor closed in the winter and open in the summer