Below is a transcription of this video, which was created by the Hager Companies.
Hager’s 5100 door closer comes in adjustable sizes 1 through 6. This is directly related to how much force is needed to open a door and the resulting force the closer is exerting to close the door.
If the door seems too heavy, you will need to adjust to a smaller size. If the door seems too light, you will need to adjust to a larger size. The closer comes factory preset to size 3. To change the size, you will need to use an Allen wrench or hex wrench in the springboard located at the end of the closer body. You will need to turn 4 revolutions per size. Turn clockwise to increase size, which increases spring power, and counterclockwise to decrease spring power.
Backcheck is the cushioning that you feel at 65 to 80 degrees during the opening cycle. For the 5100, if mounting the closer in the parallel arm configuration only, you will need to ensure that the back check selector valve is fully tightened in the clockwise direction. This will allow for adjusting the back check function. If the valve is not fully tightened, you will not get proper adjustments. The function is adjusted with the valve shown using an Allen wrench. Tightening the valve turning clockwise will increase the back check. Loosening the valve turning counterclockwise will decrease the back check. It is extremely important not to back the valves all the way out as this will ruin the closer. Do not force.
Closing or sweep speed is also adjusted by using an Allen wrench on another valve as indicated. Turning clockwise slows down the closing speed of the door. Turning counterclockwise will cause the door to close at a faster speed.
Latch speed is the last 7 to 10 degrees during closing, speeding up the door just enough to overcome weather stripping, building air pressure, wind conditions, etc. This adjustment is also made by using another valve indicated. Turning the valve clockwise will slow the door, whereas turning the valve counterclockwise will increase the latch speed.