Marley Engineered Products 410143000 Limit Switch 30067439-890 The FT rating indicates the

The FT rating indicates the thermal class of the insulation system

which is critical for clearance planning within the mechanical room or crawlspace

or producing excessive humming/chattering during operation

When you're troubleshooting a York furnace that isn't hitting temp or is cycling on a limit switch

Marley Engineered Products 410143000 Limit Switch 30067439-890 The FT rating indicates theThe Marley Engineered Products 410143000 Limit Switch is an essential OEM replacement part engineered for precise thermal regulation in electric baseboard heaters and forced air units. This heavy duty high limit safety control operates within a fixed 180 220F range, providing critical protection against overheating in residential and commercial heating systems. Unlike manual resets, this automatic reset temperature switch simplifies maintenance by