Drain Pan Switches

Drain Pan Switches

The Drain Pan Switches category focuses on the float and water-sensing switches installed directly in HVAC condensate pans to protect buildings from expensive water damage. Any time an air handler, fan coil or furnace is installed over finished areas, a properly wired drain pan switch becomes the last line of defense against clogged drains, failed pumps or cracked pans. These devices are designed to monitor water level in primary and secondary pans and immediately shut down the equipment when overflow conditions are detected.

Here you’ll find clip-on primary pan switches, secondary pan “edge” switches, low-profile float switches, multi-position switches and universal pan-mounted safety switches. Many models are designed to mount on the lip of an auxiliary pan, inside the primary pan, or at the outlet, using adjustable brackets to match different pan depths. Switches are typically wired into the low-voltage circuit to open the control signal on high water, stopping cooling or heating operation before the pan overflows. Some designs incorporate test levers or removable floats to simplify commissioning and future service checks.

• Primary pan float switches mounted inside the main drain pan.
• Auxiliary/secondary pan switches that protect ceilings and below-floor spaces.
• Clamp-on and edge-mount designs to fit a wide range of pan styles.
• Multi-orientation switches for horizontal, vertical or angled mounting.
• Service-friendly switches with accessible floats for periodic testing.

When selecting a drain pan switch, confirm the pan depth, mounting style, voltage rating, contact type (normally open/normally closed) and local code requirements. Equipment in attics or above finished ceilings should always have a switch in the auxiliary pan, and many manufacturers recommend or require a primary pan switch as well. Ensure the float is positioned so it reacts early enough to stop the system before water reaches the pan edge.

Pro tip: After wiring in a new drain pan switch, slowly add water to the pan and verify that the system shuts down instantly. Label the switch in the air handler compartment so future technicians know where the overflow protection is located and how to test it during seasonal maintenance.