Liftmaster K24-24-03 replacement Relay (3PDT, 24V, 10A) Commercial Operators
The LiftMaster K24-24-03 relay is a control-circuit replacement part used in select LiftMaster commercial door and gate operator assemblies. It is a 3PDT relay, meaning it provides three-pole, double-throw switching for circuits that need multiple contacts to change state at the same time. In the field, relays like this are often replaced when an operator no longer responds correctly to control commands, a circuit does not transfer as expected, or the relay contacts are worn, burned, or mechanically sticking.
This part should be treated as an electrical-box component, not a universal relay for every LiftMaster operator. The safest way to identify it is by the number printed on the existing relay or by the LiftMaster parts diagram for the specific operator. Many commercial door and gate operators have similar-looking relays with different coil voltages, amperage ratings, or contact layouts, so matching the K24-24-03 / 24-24-03 number matters.
Use this relay only in compatible operator circuits that call for a 24V, 10A, 3PDT relay. If the operator has burned wiring, repeated fuse failures, chatter, or visible heat damage around the relay socket, the circuit should be diagnosed before replacing the relay.
Compatible With
- Select LiftMaster commercial door operators using relay K24-24-03
- Select LiftMaster commercial gate operators using relay K24-24-03
- Commercial operator electrical boxes where the parts diagram calls for 24-24-03
- Control circuits requiring a 3PDT, 24V, 10A LiftMaster relay with matching socket and wiring
- Not interchangeable with 115V, 230V, DPDT, or different amperage relays unless the parts diagram confirms it
Features & Specifications
| Manufacturer | LiftMaster |
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| Product Type | Replacement relay |
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| Part Number | K24-24-03 |
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| Relay Type | 3PDT |
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| Voltage | 24V |
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| Contact Rating | 10A |
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| Application | Select commercial door and gate operator control circuits |
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| Notes | Match original relay number, coil rating, and contact arrangement before installation |
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Also Known As / Related Part Numbers
- K24-24-03
- 24-24-03
- LM-K24-24-03
- LiftMaster 24-24-03
Technician Note
A relay can fail because of age, heat, contact wear, moisture, or a problem elsewhere in the control circuit. If the replacement relay fails quickly, chatters, or shows heat discoloration, look for a wiring, accessory, transformer, or control-board issue instead of repeatedly replacing the relay.
Before Ordering
- Match K24-24-03 or 24-24-03 on the existing relay or parts diagram
- Confirm the relay is 3PDT, 24V, and 10A
- Compare terminal layout and socket style before powering the operator
- Do not substitute a 115V, 208/230V, or DPDT relay by appearance only
Professional Advisory
Relay replacement may expose high-voltage wiring inside commercial door and gate operators. Disconnect power at the proper source and use a qualified technician when electrical diagnosis is required.
Important Ordering Warning
Similar LiftMaster relays can look close but have different coil voltages or contact arrangements. Ordering by appearance alone can cause wrong operation or equipment damage.
Product Q&A
Is K24-24-03 a universal LiftMaster relay?
No. K24-24-03 should be used only where the LiftMaster parts diagram or original relay identifies a 3PDT, 24V, 10A relay with this part number.
What symptoms can point to a bad relay?
Possible signs include intermittent operation, a relay that does not click, burned contacts, control circuits that do not transfer, or an operator that works only part of the time. The circuit should still be diagnosed before replacing parts.
Can I replace K24-24-03 with a 115V or 230V relay?
No. The relay coil voltage and contact arrangement must match the operator circuit. A different voltage relay is not a safe substitute unless the manufacturer parts diagram specifically calls for it.
Where is this relay usually located?
It is typically found inside the operator electrical box or control compartment on compatible commercial door or gate operators.
Should a technician install this part?
Yes, a qualified gate or commercial door technician is recommended when the relay is inside a high-voltage control box or when the cause of failure is not clear.
