Carrier Circuit Board Kit 325878-751

Carrier / Bryant / Payne 325878-751 Main Control Board Kit | OEM

The Carrier 325878-751 is a genuine factory-authorized main control board kit designed for Carrier, Bryant, and Payne gas furnaces. This Original Equipment Manufacturer (OEM) kit is the designated service replacement for a wide range of legacy control boards, providing the most up-to-date logic and safety protocols available for your heating system.

This kit features the current HK42FZ034 circuit board. Because newer boards often have different wiring configurations than older versions, this kit includes a necessary wiring harness and detailed installation instructions to ensure a safe and successful upgrade.

Compatibility & Cross-Reference

The 325878-751 service kit is engineered to replace the following legacy part numbers:

• Replaces P/Ns: HK42FZ004, HK42FZ007, HK42FZ008, HK42FZ009, HK42FZ011, HK42FZ013, HK42FZ016, CEPL130438-01, and HK42FZ034.
• Common Model Series: Found in many popular units, including 58PAV, 58RAV, 58MCA, 58MXA, 350MAV, 383KAV, 395CAV, and PG9MAA series furnaces.
• Fitment Note: If your existing board matches any of the part numbers above, this specific kit is required to ensure proper mounting and electrical connection.

Why Choose a Genuine Carrier OEM Board?

Using a genuine Carrier board over an aftermarket alternative is critical for the long-term health of your furnace:

• Heat Exchanger Protection: OEM boards are programmed with specific blower "on-delay" and "off-delay" timings tailored to your furnace’s efficiency rating (80% vs 90%+). Aftermarket boards with fixed timings can cause stress cracks in the heat exchanger due to improper cooling.
• Enhanced Safety: This board utilizes a proprietary internal safety algorithm for flame sensing that generic boards lack, ensuring the gas valve closes immediately if a safe flame is not detected.
• Superior Component Ratings: The cooling relay on this OEM board is rated for 20 amps, doubling the capacity of many 10-amp aftermarket versions, which prevents relay failure during high-demand summer cooling.
• Igniter Reliability: The software ensures the Hot Surface Igniter (HSI) is de-energized the moment a flame is sensed, significantly extending the life of your igniter.

Shipping & Order Details

• Continental US Shipping: We offer reliable shipping rates for all orders delivered within the Continental United States.
• International & Other Locations: Please contact us directly for current shipping rates to locations outside the continental US.
• Authenticity: We only stock brand-new, genuine Carrier, Bryant, and Payne parts.

Technical Specifications

There is a replacement board on the market for this board that is made by ICM. I have been asked repeatedly why the Carrier replacement is more expensive. The following is cut and pasted from an email from Carrier Corp and explains the difference in the 2 boards

Thanks for the note.  I must inform you that our Engineering community has reviewed the specs on ICM boards, and have determined the following issues:

This control has 60 second on-delay only. If used on an 80% product it will have major HX (heat exchanger failure issues.

Since they do not detect furnace type or backward compatibility they will probably have one post purge timing. They may not have pre-purge or post purge at all. 

The cool relay is rated for 10 amps only and ours is rated for 20 amps.

We have an unpublished internal safety algorithm that this control does not have. It relates to flame sense.

If running continuous fan or heat pump mode they may not shut the blower  off when the igniter is energized. If not this could cause nuisance circuit breaker trips.

The control has higher resistance load resistors and may have compatibilty problems with some thermostats. (Based on photo)

The control may not shut off the HSI the moment that flame is sensed. This will give reduced reliability on a Power Heat igniter.

When replacing one control in twinned furnaces both controls must be changed.

Carrier's flame sense software is quite extensive in regards to checking the circuitry and how it detects flame. This control may not supply the same level of safety as theiir software.

These controls may not be UL or CSA listed