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Furnace Parts DIY
Carrier 3 Limit Switch 543-037 replacement part for Carrier furnaces

Furnace Parts DIY

543-037

$72.00

+5% Tax • Shipping calculated at checkout.

U.S. Duties/Taxes, if applicable, may be due at time of delivery.

Name

3" HIGH LIMIT SWITCH L190-40F

Low stock — only 1 left

Pickup available at 75 Blue Mountain St #3, Coquitlam

Usually ready in 24 hours

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Not sure this fits your furnace? Call us — we're happy to help

Product Details

Description

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.

Specifications

Type
HVAC High Limit Control Switch
Size
3-inch
Dimensions
3 inches
Application
Used in high-efficiency gas furnaces and central heating units to provide thermal overload protection and system safety monitoring.
Specifications
Open Temperature: 190°F; Close/Reset Differential: 40°F (Resets at 150°F); Circuit Configuration: Normally Closed (NC); Reset Type: Automatic.

Not sure this is the right part?

Our team is happy to help you verify compatibility before you order. We'll confirm it fits your specific furnace model.

1-778-759-9864

Mon–Sat 8AM–5PM PT · Or email parts@bcfurnace.com

Common questions

Is the 543-037 a genuine Carrier part?

Yes. The 543-037 is a genuine Carrier OEM part, sourced from an authorized Carrier parts distributor. This 3 Limit Switch is backed by our 100% compatibility guarantee — if it doesn't fit your furnace, we'll make it right.

How do I know if the 543-037 is compatible with my furnace?

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.

How fast can I get the 543-037 shipped?

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.

Can I pick up the 543-037 at your store?

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.

Where usedFits 14 furnace models

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