Replace Furnace Circuit Board – Gold Coast, Chicago, IL

Purpose of a Circuit Board

A furnace circuit board controls every major function of a modern heating system. It is commonly referred to as a control board. It serves as the system’s central processor and directs each component in the correct sequence. When the thermostat calls for heat, the board immediately begins the ignition cycle. It sends power to the inducer motor to establish proper draft and checks the pressure switch to confirm safe venting conditions.

The control board also energizes the igniter or pilot assembly. Once ignition occurs, it opens the gas valve to release fuel. It verifies flame presence through the flame sensor circuit. After confirming a stable flame, it activates the blower motor to distribute heated air throughout the ductwork. The board continuously monitors safety circuits and manages system lockouts when necessary. If it detects a fault, it shuts the furnace down to prevent damage or unsafe operation. Many boards display diagnostic codes that help technicians quickly identify system issues.

How to Replace a Circuit Board

When a circuit board fails, we replace it carefully. First, we shut off power to the furnace at the breaker panel. We then use a tool called a multimeter to confirm that no voltage is present. Next, we remove the furnace access panels to reach the control compartment. We take clear photos of all wiring connections before disconnecting anything and label each wire to ensure accurate reinstallation.

We then disconnect the thermostat wires, line voltage leads, etc. After removing the mounting screws, we carefully lift out the old board without damaging surrounding wiring. We install the replacement board in the same orientation and secure it using the original mounting points.

Finally, we reconnect all wiring and restore power to the furnace. We start a heating cycle and observe the full ignition sequence. During testing, we confirm proper inducer operation, ignition, gas valve function, and blower startup. We also check for diagnostic codes and verify safe, consistent system performance.

Sound complicated? Leave it to the experts. Call Service Pro Titans at (312) 312-7312 to schedule professional furnace repair or circuit board replacement.