Can You Put a Three-Way Switch on a Wood Furnace Blower?

Three-Way Switches

• Three-way switches allow for three different circuits that can be controlled by the switch. In some setups, these three terminals allow for two different switches that control the same blower. In other situations the three-way switch may control two different settings on the blower so you can switch between the two, but not use both at the same time. These switches have applications across electrical systems.

Thermodiscs

• If you're installing a blower in your wood furnace or fireplace, check the type of blower and how it activates. This can provide important clues for using three-way switches. Many blowers use thermodiscs to automatically detect temperatures and switch blowers on when the fire is hot enough to efficiently heat a room. In this case, a three-way switch can be superfluous to the system and you can probably skip installing one. But for systems that require you to flip a switch when turning on the blower, three-way switches are usually possible.

Blower Speeds

• A common use of a three-way switch in a blower is controlling the blower's speed. Turning a blower on and off from two different switches has limited applicability, but moving the blower between a low speed and a high speed can be much more useful. In this case, there is one switch with at least two speed options, connected to the blower. Your blower must have the capability of alternating between speeds before you install this type of switch.

Considerations

• If you're installing a three-way switch so you can turn your blower on and off from multiple locations, consider purchasing and installing a blower remote instead, so you can operate your blower wirelessly. This may also be an option for controlling blower speeds, and also works for more typical three-way switches that can control a gas fireplace if you want to switch fuels.