Furnace Repair Downriver MI.: How to Know If the Furnace Control Board is Bad - Downriver HVAC


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Furnace Repair Downriver MI. How to Know If the Furnace Control Board is Bad

Is it a burning plastic or electronic equipment that you smelled recently from your furnace? Immediately contact your furnace repair Downriver MI. Consequently, the malfunctioning furnace control board could cause the smell. Many factors can cause control boards to malfunction. Often, a board will fry as a result of a short circuit. Sometimes an electrical component will act strangely due to a problem. Or if your furnace completely refuses to turn on.

Furnace Repair Downriver MI: Learn How to Identify Faulty Furnace Control Board  

Here are tips from experts in furnace repair Downriver MI. on things to consider to know if your control board is bad. Most of the time, problems with a furnace stem from something other than the control board. Determining whether your control board was already bad is crucial because of this.

Remove the Access Panels on the Furnace

Remove the furnace’s front access panels. Usually, the control board is next to the blower in the bottom access.

Examine the Control Panel

Check out the control panel. Are there any burn traces on it? Is there a strange odour emanating from it? A control board may have blown up occasionally. Your control board needs to be fixed in that situation.

Check the Diagnostic Light on the Control Board

The diagnostic or indicator light on the control board should be checked next. Depending on what is occurring in the control board, the diagnostic light may often blink repeatedly. For instance, three flashes can indicate that the inducer pressure switch is not triggering on the furnace.

The light won’t be on if your control board is powered off. You can determine precisely what is wrong with the furnace by checking the diagnostic light on the control board.

Most of the time, there won’t be an immediate problem with the control board; instead, it will be with one of the furnace’s other parts.

Examine the Power as It Enters the Control Board

Check for power entering the control board if the diagnostic light on the control board isn’t blinking.

Locate the wire that the control board is powered by. The wire typically has a 120VAC Hot label and is black. It would be best if you made sure the door switch on your furnace is pressed in. To keep the control held down, use some tape.

If your control board receives 120 volts of AC, it is powered. If your control board is powered on but not illuminated by the diagnostic light, it is likely damaged and has to be replaced. To check the electricity in your furnace, you’ll need a multimeter. This is why you need a professional furnace repair Downriver MI. to handle this. 

Thermostat Terminals Must Be Jumped

You will do some tests after ensuring that the control board receives electricity.

Turn off your furnace first. Next, use a wire to connect the “R” and “G” connections. Restarting your heater should turn on the blower.

Instead, connect the “R” and “W” connections to test the heating (see pictures below). Jump the “R” and “Y” terminals to test cooling.

The furnace control board is not malfunction if your furnace starts up after you jump the terminals. The thermostat is more likely to be the issue.

Check the Control Board’s Power Supply

Next, make sure that your control board is getting electricity. Because you must understand what each terminal on the control board is for, this is challenging.

Start by checking the outputs from the control board with your multimeter. Control boards typically use relays to turn on and off various components, including the blower, ignitor, and gas valve.

A wiring diagram is printed inside a furnace’s door or control panel. Using the wiring schematic, you may determine which points need testing.

The order of the furnace’s activities must also be known. Sometimes, a pressure or high-limit switch will prevent a control board from turning on your furnace.


Not every homeowner can handle this process. So you need an expert furnace repair Downriver MI. to check this out for you. Your control board is probably broken if your furnace has no other problems and there is no voltage output to the furnace’s internal parts. Therefore it calls for immediate repair. 


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