Mitsubishi Electric · R410A Systems
The mechanism designed to prevent drain pan overflow in the indoor unit is not functioning correctly. This could be due to a faulty drain sensor, a malfunctioning condensate pump, or a clogged drain line, leading to water damage.
Click steps to track your progress.
Verify the drain sensor (P4) is operating correctly by checking its resistance or output.
Inspect the condensate drain line for blockages, kinks, or improper slope that could impede water flow.
If a condensate pump is installed, verify its operation and check its float switch for proper activation and deactivation.