Furnace Failures: What You Need To Know About Troubleshooting The Draft Inducer

Your furnace functions by drawing air into the system, passing it through a heat exchanger and then routing it out to your home through a vent pipe into your air ducts. A small fan component, called a draft inducer, pulls the air into the furnace to start this cycle. Since this inducer plays such a vital role in the operation of your furnace, it's important to know the early signs that it's failing and the basics of how to address it. With this information, you can spot and correct problems before they lead to failure.

Potential Inducer Trouble Signs

There are a few key warning signs that your inducer fan needs attention. For example:

The inducer motor runs and the fan is turning, but there's no response from the furnace – this is a sign that the vent pipe may be clogged or you have condensate in the inducer. In either case, this is an easy repair for a furnace technician.

The inducer motor isn't running at all – if the motor on the draft inducer isn't running at all or is only starting up part of the time when it should, it may need to be replaced. To find out for sure, feel the case around the inducer. If the case around the motor is hot to the touch, that's an indication that it's time to replace it.

Tips to Replace the Inducer Motor

Start by turning off the power to your furnace. It's typically best to do this at the breaker panel so that you can be sure that there are no surprises as you work. Then, let the furnace cool for a little while so that you can work safely.

Removing the Old Unit

Start by marking each hose and wire connected to the inducer using tape that you can write on. Then, assign a number or letter to every one of them. Make a note of each number assignment and where that number connects on the new inducer so that you can reattach them properly.

Then, disconnect the vent pipe and the drain tube by pulling them out of their connections. Use a screwdriver to take the mounting screws out. Set them aside and pull the draft inducer off the furnace.

Installing the New Unit

Line up the new inducer in the same place where you removed the old one. The new inducer may come supplied with a high-temperature silicone or rubber gasket. If so, place this gasket between the inducer assembly and your furnace before you secure the inducer in place. Replace the mounting screws, turning them until they are hand-tight. Don't overtighten them so you don't damage the screw.

Follow your labels and diagram to reconnect the wiring, hose and drain tube. Finally, reattach the vent pipe and restore power to the furnace.

If the inducer assembly was the source of the problem, this should restore your normal furnace operation. Talk with a furnace technician if this doesn't correct the issue and he or she can help you narrow things down. It could be that furnace replacement is necessary.