Circuit Breakers

Lennox replacement circuit breakers are OEM-designed electrical protection components built specifically for Lennox furnaces, air handlers, heat pumps, and electric heat kits. Every circuit breaker in a Lennox HVAC system serves one critical function: interrupting current flow the moment an overload or short circuit occurs, protecting both the equipment and the wiring connected to it. A properly matched replacement breaker, like the 97W36 2-pole, 60-amp unit, carries the same trip characteristics and physical fit as the original, keeping the system within its designed electrical envelope. When a breaker trips repeatedly or fails to reset cleanly, it's a signal worth taking seriously. Lennox replacement circuit breakers make a like-for-like swap straightforward, with no guesswork on amperage ratings or form factor.

Standalone circuit breakers and electric heat kits with integrated circuit breakers cover the two main scenarios an HVAC technician encounters on a Lennox job: replacing a failed protection device in an existing system, or adding electric heat capacity to an air handler that needs it.

KEY SUBCATEGORIES / PRODUCT TYPES

Standalone Lennox Replacement Circuit Breakers

Standalone Lennox replacement circuit breakers cover a range of amperage ratings for different protection points inside an air handler or furnace cabinet. The 97W36 is a 2-pole, 60-amp molded case breaker used in higher-draw circuits. The 17K70 handles 30-amp single-circuit applications. The 26W34 and 37J56 both operate at 3 amps, 250 volts, and protect the low-voltage transformer and control circuit. The 37J56 is a push-to-reset fuseholder-type thermal breaker for panel-mount installations where manual field reset matters. Matching the replacement to the original part number is the most reliable way to confirm the trip curve, pole configuration, and mounting style align with the existing installation.

ECB47 Electric Heat Kits with Integrated Circuit Breakers

The ECB47-9CB-P electric heat kit (SKU 27A27) is a 9 kW, 208/230V, single-phase heat kit with an integrated circuit breaker, designed for field installation inside compatible Lennox air handler cabinets. The ECB47-12.5CB-P kit (SKU 27A28) steps up to 12.5 kW and includes two circuit breakers: one 30-amp and one 45-amp, matched to the dual-element heater configuration. For larger load requirements, the ECB47-15CB-P kit (SKU 27A23) delivers 15 kW at 240V and includes a 35-amp and a 60-amp circuit breaker. Each kit uses helix-wound nichrome heating elements exposed directly in the airstream, transferring heat instantly at low element temperatures. ETL-listed for field installation internal to the unit cabinet, the ECB47 series installs alongside CBX and compatible air handler families.

BUYING GUIDE / HOW TO CHOOSE

Choosing between a standalone circuit breaker and a heat kit with integrated breakers depends on what the system needs. If a breaker in an existing heat kit has tripped and won't reset, or has failed entirely, the standalone replacements cover the most common protection points without requiring a full kit swap. If the goal is adding electric heat capacity or replacing a full heat section, the ECB47 kits arrive pre-assembled with matched breakers and heating elements, reducing field assembly time.

When specifying a replacement heat kit, confirm the air handler model series against the kit's application table before ordering. ECB47-series kits are application-specific. For the standalone low-voltage breakers, the 37J56 replaces older Lennox part numbers including 10K63 and 10K6301 and fits Allied, Armstrong, Concord, and Ducane equipment, making it a practical stock item for technicians servicing multiple brands in the same product families.

For the high-amperage breakers, amperage rating and pole count are the two non-negotiables. The 97W36 is a 2-pole, 60-amp breaker. The 17K70 is a single-circuit 30-amp breaker. Installing the wrong amperage rating can leave circuits under-protected or cause nuisance tripping, so confirming against the original part number before pulling the trigger is always the right call. For the low-voltage control circuit breakers, the 26W34 and 37J56 are both 3-amp, 250-volt devices, but differ in design and mounting style. When replacing Lennox circuit breakers in any of these applications, always de-energize the unit and follow lockout/tagout procedures before beginning work.

FAQs

What amperage is the Lennox 97W36 circuit breaker?

The Lennox 97W36 is a 2-pole, 60-amp molded case circuit breaker used in Lennox air handlers and heat pump systems requiring high-draw circuit protection. The 97W36 replaces earlier Lennox part numbers including 17K72 and QOU260.

What is the difference between the Lennox 26W34 and 37J56 circuit breakers?

Both the 26W34 and 37J56 are 3-amp, 250-volt low-voltage circuit breakers for Lennox HVAC control circuits, but the 37J56 is a push-to-reset fuseholder-type thermal breaker designed for panel mounting that replaces older Lennox part numbers 10K63 and 10K6301. The 26W34, catalog number 100597-01 at LennoxPros, is a standard circuit breaker for transformer and control circuit protection. Selecting between the two depends on the original part installed in the system.

How many circuit breakers are included in the Lennox ECB47-12.5CB-P kit (27A28)?

The ECB47-12.5CB-P electric heat kit includes two circuit breakers: one 30-amp and one 45-amp, matched to the dual heating elements in the 12.5 kW, 240V configuration. At 208V, the same kit delivers 9.4 kW.

What air handlers are compatible with the Lennox ECB47-15CB-P heat kit (27A23)?

The ECB47-15CB-P is a 15 kW electric heat kit designed for field installation in compatible Lennox air handler cabinets. Compatibility should be confirmed against the specific air handler model series application table in Lennox documentation before ordering, since ECB47-series kits are application-specific.

When should the Lennox 17K70 30-amp breaker be used instead of the 97W36 60-amp breaker?

The Lennox 17K70 is a 30-amp breaker suited for lower-capacity circuits, while the 97W36 is a 2-pole, 60-amp breaker for higher-draw applications like larger electric heat sections and air handler main circuits. Matching the replacement to the amperage rating and pole configuration of the original is required to maintain proper overcurrent protection for the system.