Service diagnostic found that the condensation drain line was clogged. Water had backed up into the secondary drain line and tripped the safety switch. I also found that the condenser fan motor showed signs of overheating. There was biological growth inside the air handler. Options for repair were presented to the homeowners. They chose to have the drain line cleared, the condenser fan motor replaced and to have system sterilizers installed inside the air handler. I cleared the drain line and flow tested the drain with two gallons of water. I also treated the drain line. I replaced the condenser fan motor and installed system sterilizers inside the air handler. I function tested the system and the system was operational. The system was running at the completion of service.