Carrier 20054502 Timer Board

When you are out on a service call and encounter a failed blower control, the Carrier 20054502 Timer Board is the direct OEM solution for restoring high-efficiency fan timing to gas-fired furnaces. This furnace fan timer control is manufactured by Honeywell and is technically identical to the ST9120C2010, making it a critical component for managing the combustion blower and circulating fan operations. It operates on a standard 18 to 30 Vac power requirement and features field-adjustable DIP switches, allowing you to fine-tune heat fan-on and fan-off delays to prevent cold air drafts at the start of a cycle and maximize latent heat recovery at the end. The board supports intermittent pilot ignition and SmartValve system applications, ensuring broad HVAC system compatibility across Carrier and associated Bryant or Payne equipment. Designed for durability in high-heat environments, this electronic fan timer provides precise circuit board timing, ensuring the heat-speed fan activates and deactivates exactly when the gas valve is energized or de-energized.

Key Benefits

• Direct Cross-Reference: 100% replacement for Honeywell ST9120C2010 and earlier ST9120 series models, simplifying your truck stock.
• Customizable Timing: Field-adjustable DIP switches provide selectable fan delay settings (30/60 seconds on, 60/100/140/180 seconds off) to match original equipment specifications.
• Reliable Load Management: Rated for a 15A full load at 115 Vac for heat-cool speeds, providing robust power handling for high-demand blower motor control.
• Integrated Diagnostics: Simplifies troubleshooting with a centralized wiring point for the thermostat, limit switches, and gas valve.

Common Questions

Is the Carrier 20054502 compatible with other ST9120 models?
Yes, this board is the primary replacement for the ST9120C2010 and can often replace other fixed-timing boards when configured with the correct DIP switch settings as per the appliance manual.

How do I set the fan delays on this board?
Timing is adjusted via the onboard DIP switches. Refer to the table on the protective cover or your service manual to set the "Heat Off" delay, which is vital for consumer comfort and system efficiency.

Does this board control the inducer motor?
Yes, this electronic fan timer manages both the combustion blower (inducer) and the main circulating fan to ensure proper post-purge and heat exchange timing.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.