How to Troubleshoot a Trane Float Switch

A wet floor is sign that the float switch is not working on the air conditioner.

A bad float switch usually presents itself with either water on the floor or an air-conditioner that keeps shutting itself off. These problems could also happen because of a blown fuse, bad transformer or a cracked drain pan. Because the float switch rests on the outside of the air handler, it can be easily checked. A float switch either works or it does not. So, if yours is not working, it's time to replace it.

Things You'll Need

• Ohm meter

Instructions

1. Turn off the power to the air handler (the inside unit) at the circuit box.

2. Check whether the float switch is installed so that the wire comes out at the top.

3. Put the ohm meter on "beep mode." Touch two leads (the metal tips) to each end of the two wires connecting the float switch to the air handler. It makes no difference which lead touches which wire.

4. Listen for a beep sound, which will indicate the switch is closed as it should be and the float switch is working.

Tips & Warnings

• Replace the float switch if you do not hear a beep during the test.

References

• Alan Boleware, Service Technician; Complete Air and Heat, Inc.; Indian Harbour Beach, Fla.