LiftMaster 03-35711 Contactor Relay, 24V, 2NO + 2NC

LiftMaster 03-35711 Contactor Relay, 24V, 2NO + 2NC

The LiftMaster 03-35711 contactor relay is a replacement relay for commercial operator electrical boxes. It is used in the control side of select LiftMaster commercial door operators where the electrical schematic calls for a 24V relay with the correct normally open and normally closed contact layout.

Most supplier references identify this part as a 24V, 2NO + 2NC contactor relay. Some older product titles may show the contact arrangement differently, so the safest match is the actual relay label, operator wiring diagram, and LiftMaster replacement parts list.

This part is normally ordered when the contactor relay in the electrical box is worn, damaged, sticking, or no longer switching as intended. It should not be used as a general-purpose substitute relay unless the coil voltage, contact rating, terminal layout, and control circuit function match the original part.

Compatible With / Common Applications

Commonly used in select LiftMaster commercial door operator electrical boxes where the diagram calls for 03-35711 or K03-35711.

• Select LiftMaster commercial overhead door operator electrical boxes
• Logic commercial operator control circuits that call for a 24V 2NO + 2NC contactor relay
• Commercial door operators using the K03-35711 / 03-35711 relay service part
• Electrical-box relay replacement applications where coil voltage and contact arrangement match
• Not a replacement for transformer kits, receiver boards, logic boards, or low-voltage wall controls

Features and Specifications

Also Known As / Related Part Numbers

• 03-35711
• K03-35711
• LIF-K03-35711
• LiftMaster 03-35711 Contactor Relay
• LiftMaster K03-35711 Contactor Relay Kit
• 24V 2NO + 2NC contactor relay

Technician Note

The source title in some catalogs may show the contact arrangement as 2NC + 2NC, but multiple supplier references list this relay as 2NO + 2NC. Match the physical relay and wiring diagram before upload or order fulfillment.

Before Ordering Checklist

• Confirm the old relay label or parts diagram calls for 03-35711 or K03-35711
• Confirm 24V coil voltage
• Confirm the contact arrangement and terminal layout match the original relay
• Inspect for burnt terminals, loose wiring, or upstream control faults
• Do not replace this part to bypass a safety or stop circuit problem

Professional Advisory

Commercial operator electrical boxes can contain hazardous voltage. Relay diagnosis and replacement should be performed by a qualified technician, especially when motor control or stop-circuit symptoms are present.

Product Questions and Answers

Is 03-35711 the same as K03-35711?

Yes, K03-35711 is commonly used as the kit or service part reference for the 03-35711 LiftMaster contactor relay.

What does 2NO + 2NC mean?

It refers to two normally open and two normally closed contacts. The contact layout must match the original relay and operator wiring diagram.

Can this relay fix an operator that will not run?

It may if the original relay has failed, but no-run issues can also be caused by power, stop circuit, safety device, logic board, limit, or motor problems.

Is this part used in residential garage door openers?

No. This relay is for select LiftMaster commercial door operator electrical boxes, not standard residential opener wall controls.

Should I replace this relay without testing the circuit?

No. A failed relay can be a symptom of another issue. Check the control circuit and wiring before installing the replacement.