3" HIGH LIMIT SWITCH L170-30F 3 High Limit Control Switches
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Pickup available at 75 Blue Mountain St #3
Usually ready in 24 hours
Not sure this fits your furnace? Call us — we're happy to help
Ensure your heating system operates safely with this premium 3-inch high limit switch. Designed as a critical safety component for residential gas furnaces and forced-air HVAC systems, this thermal limit control prevents dangerous overheating by monitoring internal plenum temperatures. The switch is engineered to automatically interrupt the heating cycle when temperatures reach the 170-degree Fahrenheit threshold, protecting your heat exchanger and home from potential damage. Featuring a 30-degree differential for a reliable automatic reset once the unit cools to 140 degrees, this high limit sensor is an essential replacement part for restoring furnace safety and efficiency. Ideal for HVAC maintenance and heater repairs, this durable limit control switch provides consistent climate control performance and equipment protection.
Our team is happy to help you verify compatibility before you order. We'll confirm it fits your specific furnace model.
1-778-759-9864Mon–Sat 8AM–5PM PT · Or email parts@bcfurnace.com
Compatible parts and related replacements
Yes, the 543-004 is a genuine OEM, or a factory replacement manufacturer approved part. We source all 3 Limit Switches from authorized distributors to ensure exact-fit compatibility. This 3 Limit Switch is backed by our 100% compatibility guarantee — if it doesn't fit your furnace, we'll make it right.
The easiest way is to match the part number (543-004) with your furnace model number. Visit the homepage and enter your model number in the search bar — our system will show all compatible 3 Limit Switches for your specific unit. You can also call our technicians at 1-778-759-9864 for free compatibility verification.
Most 3 Limit Switches including the 543-004 ship within 1–2 business days from our warehouse. We ship across Canada and the United States, and worldwide, with tracking on every order. For urgent furnace repairs, contact us at 1-778-759-9864 for expedited shipping options.
Yes! Local pickup is available at our Coquitlam, BC location: 75 Blue Mountain St #3. 3 Limit Switches orders are usually ready within 24 hours. Call us at 1-778-759-9864 to confirm the 543-004 is in stock before visiting.
Still not sure this is the right part? Call 1-778-759-9864 and we will check your model number with you.
The model number is on the rating plate inside the furnace door.
129 more not shown. Check your own model number above.
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