The door is closing too fast or too slowAdjust the closing and latching speed valves to achieve a suitable door closing speed. The door closer is not latching the lock properly First, ensure the door is swinging and latching freely with the door closer disconnected from the door. Check if the door closer is the correct power for the door Check if the door closer is installed correctly Check if the door closer is adjusted correctly (power, closing, latching) My parallel arm door closer is lacking powerNeed to factor in power loss of approximately 20% when using parallel arm configuration. Additionally, arm must be pre-loaded per the instructions. My slide rail door closer will not let the door open all the way.Slide rail door closers have limitations on how far the door may open. This should be assessed prior to installation of the door closer, for suitability of the closer to the door. A door stop should be used to prevent opening the door past the closers’ limit. Does temperature affect the hydraulic valve settings?Yes, it can and its affect may be noticeable at extremes of heat and cold.