CA
3" HIGH LIMIT SWITCH L190-40F 3 High Limit Control Switches
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Not sure this fits your furnace? Call us — we're happy to help
This 3-inch high limit switch is a vital safety component for residential gas furnaces and HVAC systems. Designed to monitor the internal temperature of the heat exchanger, this limit control acts as a safeguard against overheating. If the furnace reaches a temperature of 190°F, the switch automatically opens the electrical circuit to the gas valve, halting the heating process to prevent equipment damage and ensure home safety. Once the system cools down by 40°F, the switch automatically resets to allow for normal operation. Replacing a faulty high limit switch is essential for maintaining reliable performance and preventing frequent furnace cycling or total system lockout.
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–9PM PST · Or email parts@bcfurnace.com
Compatible parts and related replacements
Yes, the 543-037 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 (543-037) 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 543-037 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 543-037 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.
2 more not shown. Check your own model number above.
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