The LiftMaster 33LM is a three-button Open/Close/Stop remote transmitter engineered for commercial and industrial door operators that use 390 MHz radio control. Designed to provide dedicated commands for raising, lowering, and halting a door, it’s commonly used with sectional and rolling steel doors, shutters, and commercial gate systems that accept three-wire radio control. As a direct replacement remote in the LiftMaster 390 MHz family, it offers straightforward handheld or visor-mounted control for dock doors, warehouses, and other commercial applications where precise, separate functions are required.
Operating at 390 MHz, the 33LM works with compatible LiftMaster/Chamberlain receivers that use code-switch (DIP switch) programming and are wired to the operator’s Open/Close/Stop inputs. Setup typically involves matching the remote’s internal code switches to the receiver’s code and, where applicable, assigning the three buttons to the receiver channels that control open, close, and stop—refer to the operator or receiver manual for channel wiring and logic. This model is not compatible with Security+ or Security+ 2.0 rolling-code systems, MyQ, or 315 MHz equipment. For best performance, ensure the receiver antenna is properly positioned and test range on site. Use only where the door or gate is in full view, and follow UL 325 and site safety procedures so the Stop function can immediately halt movement if needed.
