Heater shows E20 and shuts down; may be associated with condensate around base of unit

Safety: Turn off power. Condensate is mildly acidic; wear gloves and eye protection.

• Inspect condensate trap: Locate the Condensate Trap Assembly at the base of the heat exchanger. Remove and flush it with clean water to clear slime or debris.
• Check drain hose: Ensure the condensate hose slopes continuously downward to the drain and is not kinked or submerged in standing water.
• Test float switch: If equipped, disconnect the Condensate Float Switch and test for continuity with the trap empty and full. Replace if it does not change state correctly.
• Neutralizer maintenance: If a condensate neutralizer cartridge is installed, check for blockage and replace media if saturated.
• Test operation: Reassemble, restore power, and run the heater. Verify that condensate flows freely to the drain and that E20 does not recur.