When your Goodman furnace isn’t getting power, your home will freeze on rough winter days. A few different reasons can cause your Goodman furnace not to get any power. Let’s see what they are.
Your Goodman furnace isn’t getting power because of a faulty power supply, dead thermostat batteries, a faulty control board, or a blown fuse. You can restore power to your furnace by checking the power supply, swapping the thermostat batteries, and replacing the control board and blown fuse.
If you’re stuck with an unpowered Goodman furnace and nothing works, this article will help you get to the root of the problem. We’ll explore the most common causes behind a power failure and how to fix each issue.
Faulty Power Supply
The most common reason a Goodman furnace isn’t receiving power lies with the power supply. There are a few reasons why your power supply isn’t working as intended. With this in mind, it’s time you grab your toolkit and diagnose the power supply.
When it comes to checking the power supply, there are a few areas that you want to take a look at. The wiring that connects with the building’s power supply may be at fault. The problem may also lie with the wires that run from the fuse box to the main furnace unit.
How To Fix
To determine if the main power supply is the problem at hand, get your hands on a multimeter or a voltage meter. They’ll help you determine if there’s any current going through the wires.
You need to test the wires on both sides of the fuse box. This will allow you to determine exactly where the power failure occurs.
Here’s a quick step-by-step guide:
- Use the voltage meter to check the electrical wires from your building’s power supply.
- Check the electrical wires that come out of the fuse box. They usually come out at the bottom. The fuse box has a single switch in most cases. The switch is used to turn the power to the furnace on or off. Ensure it’s turned on when monitoring voltage in the cables with your voltmeter.
- Make sure the voltage remains stable throughout the wiring. Measure up to the furnace. See if the voltage drops at any point.
If you find that there’s no or low voltage at a specific point, check the wires. You might need to replace a few broken wires.
Dead Thermostat Batteries
While the power supply is one of the main culprits behind the issue, dead batteries in your thermostat can also cause problems.
When the thermostat’s batteries are dead, the device won’t turn on. The thermostat is crucial for controlling the furnace.
The thermostat can’t send signals to the furnace if the batteries are dead. It might seem like the furnace isn’t getting power when this happens.
How To Fix
You should first determine if your thermostat runs on batteries. Thermostats either use batteries to stay powered on or get their power from the HVAC using the C-wire. If you take the thermostat off its mounting bracket, you can take a look at its rear side.
If the thermostat is attached to the furnace and can’t be removed, it probably uses the C-wire to get its power. If you can remove it, see if there’s a battery compartment on the rear.
Double-check that the thermostat isn’t coming on when you press the power button. Take the batteries out and replace them.
The video below offers full guidance on how to replace the batteries in a thermostat:
Faulty Control Board
Electricity goes from the main power supply to the control board in your furnace. The control board then distributes both signals and electricity to other parts of the system. If something is wrong with the control board, your furnace can’t fire up.
If the control board is dead, it can’t power any part. The thermostat may turn on if it runs on batteries, but turning the furnace on will yield no reaction.
How To Fix
You’ll have to check a few things on the control board to determine if it’s faulty. A visual inspection is a great place to start, but you should use a multimeter if you have one. It’ll help you check specific points on the board to see what’s causing the power failure.
If the control board is damaged or broken, you should see some physical signs. For example, if your furnace suffered a power surge recently, the control board may have black burn marks on it.
If there are problems with the board’s voltage readings or signs of significant damage, replace the complete board. If it’s just a blown capacitor or two, you can probably replace it, and you’ll be fine.
Here’s a video that guides you through the troubleshooting steps for the control board:
The fuse box controls the power supply for your furnace. The box holds fuses and the main power switch. When you switch it off, the power supply stops at the box.
If a fuse in the box is blown, your Goodman furnace won’t get any power.
How To Fix
Thankfully, fuses are dirt cheap. After opening the fuse box, it’s time to identify and replace the broken fuse. Inspect each fuse individually to see if the wire inside is still intact.
If the wire inside is broken or you see burn marks, replace the fuse. Ensure the replacement fuse has the same rating.
Problems with the power supply are a common reason why a Goodman furnace isn’t getting power, but other issues can be at play too. Check the power supply, thermostat batteries, control board, and fuse box to ensure everything is working correctly.
If you’re experiencing any other Goodman furnace issues, make sure to check our Complete Goodman Furnace Troubleshooting Guide.