Furnace control boards can be very intimidating for newer technicians without much experience working with them. They’ll typically have many wires running to/from them, flashy lights, bulky built-in relays, resistors, and capacitors. It all looks very confusing, but it’s really not.
Ignition control boards
Ignition control boards are typical in older systems. They control the gas valve, igniter, flame sensor, and the damper (when used). With a call for heat, the board will start the sparker and light the pilot. When it senses the pilot, it will continue to light the burners.
Integrated Furnace Control (IFC)
An IFC, also known as the control board, controls everything an ignition control would and more. All safety controls, combustion blower, flame proving, gas valve, and the blower are all managed by the IFC.
Watch for burn marks on the board as they could be an indication of possible failure. The examples below are the front and backside of a relay on a control board.
Tip: Removing Plastic Mounting Pins Off a Control Board
The white plastic mounting pins holding a control board to the mounting plate can be a pain to remove easily without breaking anything or twisting back and forth with a pair of pliers over and over. Here’s a quick tip on how to remove most control board mounting pins. Below are the plastic pins that hold a control board in place.
The only thing you will need for this is a standard Bic clear pen.
Step 1: Locate 4 pins on board
Step 2: Place Bic pen over the pin and push in on the Bic while also pulling control board off the pin
Step 3: Done