E16 error, unit may lock out; often associated with condensate or blocked heat exchanger.

Safety: Turn off power before working on the condensate system. Condensate is mildly acidic; wear gloves and eye protection.

• 1. Locate condensate trap: Find the plastic condensate trap at the base of the Triangle Tube heat exchanger or cabinet.
• 2. Inspect for blockage: Disconnect the drain tubing and check for slime, debris, or scale blocking the trap or line. Clean the trap with water and a small brush.
• 3. Flush drain line: Run water through the condensate drain line to ensure it is clear to the termination point. Remove any kinks or sags that can hold water.
• 4. Check for freezing: In cold climates, ensure the drain line is not routed outdoors where it can freeze. Thaw and reroute or insulate as needed.
• 5. Reassemble and test: Reconnect all tubing securely, restore power, and run the unit. Verify that condensate flows freely during operation and that E16 does not return.
• 6. Professional service: If the internal heat exchanger passages are blocked with scale or debris, a technician should perform a chemical cleaning following Triangle Tube guidelines.