LiftMaster Q018 / K20-1050B-1RL Replacement Gate Motor — 1/2 HP, 115V AC, Single Phase

The LiftMaster Q018 is a replacement gate-operator motor identified by the supplier as manufacturer part K20-1050B-1RL. LiftMaster’s part schedule describes this motor as 1/2 HP, 115V, single phase. Select it for equipment whose exact service documentation calls for that complete reference, including the suffix. It is a motor service component, not a complete operator or a universal replacement for every 1/2 HP LiftMaster drive.

Compatibility — Models, Versions and Exclusions

Confirm the Motor Fault and the Exact Replacement Configuration

A stalled or inconsistent gate is not proof that the motor has failed. A technician should check the electrical supply, control output, connections and mechanical drive before recommending replacement. A damaged transmission component or binding gate may keep a correct motor from operating normally. The repair should address the original cause as well as any resulting damage.

Photograph the motor nameplate and its mounting arrangement, together with the operator model label. Previous service may have changed components inside an older enclosure. The complete part number is more useful than a general description such as Elite motor or half horsepower. Confirm mounting, shaft and attached drive parts from the service documentation instead of selecting on outward appearance.

Specifications and Product Identification

Before Ordering

• Read the complete existing motor number, including every suffix.
• Confirm the operator model and applicable parts diagram.
• Have the supply, control circuit and mechanical drive inspected.
• Identify any separate belt, pulley, capacitor or mounting parts required for the documented repair.

Package Contents and Separate Requirements

This listing identifies the replacement motor. A gearbox, drive belt, pulley, capacitor or complete wiring assembly should not be assumed included unless the current supplier offer expressly lists it. Check the kit inventory against the required repair so nearby components in an exploded drawing are not mistakenly treated as part of this motor shipment.

Safety Warnings — Read Before Installation or Service

• WARNING: Mains voltage and unexpected gate movement can cause serious injury or death. Motor replacement requires a qualified gate-systems technician.
• Isolate and secure every applicable power source and the gate before opening the drive or touching motor wiring.
• Do not connect this motor to a different voltage, phase or DC supply based on approximate nameplate similarity.
• Restore the required mechanical guards and verify travel, direction and all protection devices before normal operation resumes.

Related Products and Important Differences

• LMRRUL monitored photo eye — a separate safety component to evaluate only against the repaired operator’s approved accessory list.
• LMWEKITU monitored wireless edge kit — a safety-edge communication system for compatible controls; it is not part of this motor kit or a universal retrofit for older operators.

Frequently Asked Questions

Why does this use both Q018 and K20-1050B-1RL?

The supplier uses Q018 as the item reference and identifies K20-1050B-1RL as the manufacturer part number.

Will it replace any 1/2 HP gate motor?

No. Electrical characteristics, mounting and the approved service reference must match.

Is it the same as the 24V DC K76-36398 motor?

No. This listing is for the 115V AC single-phase Q018 motor. The two electrical platforms must not be confused.

Will a motor replacement fix a binding gate?

No. Mechanical problems require correction. The motor should not be used to overcome a damaged or improperly supported gate.

Need Help Confirming the Right Product?

Contact Garage-DoorParts.com before ordering. Send the full equipment model, readable part labels and photographs of the installed assembly. Include the dimensions, electrical configuration or accessory details relevant to your project so the listing can be checked against the actual installation.