The LiftMaster K001A6837 Logic Board (L4) is an OEM replacement control board for select LiftMaster commercial door operators built on the Logic 4 platform. It restores core operator functions including open/close/stop control, safety circuit management, and common Logic 4 features such as timer-to-close and service configuration options, depending on the host operator. This board is used in a range of LiftMaster commercial trolley, hoist, and gear-reduced operators from the Logic 4 era and is a direct-fit replacement when the original L4 board has failed. Compatibility varies by model; verify fitment against the operator’s model/serial and parts manual (e.g., T, H, GH, GSD and related Logic 4 series).
Designed as the central low-voltage control interface, the K001A6837 is powered by the operator’s internal transformer (commonly 24 VAC, 50/60 Hz) and provides terminals for standard three-button stations, photoelectric sensors, and other UL 325 compliant safety inputs supported by the host operator. Configuration is typically performed via on-board DIP switches and adjustment trimmers and may include settings for timer-to-close, control logic, and accessory behavior as documented in the operator’s manual. This L4 board is not interchangeable with LiftMaster Logic 5.0 or Security+ 2.0/MyQ control platforms. For safety and code compliance, installation should be performed by a qualified technician with power removed, wiring transferred one-for-one from the old board, and a complete post-installation test of all entrapment protection devices. Intended for use in commercial and industrial overhead door applications where a genuine LiftMaster Logic 4 replacement part is required.