Unit shows E18; condensate may be visible around the base of the heater.

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

• Inspect condensate trap: Locate the Weishaupt condensate trap at the base of the unit. Remove the cap or trap body as per the manual and clean out sludge or debris. Refill with clean water before refitting.
• Check condensate pipe: Follow the pipe to the drain. Ensure it slopes continuously downward with no sags that can trap water. Clear any visible blockages.
• Frozen pipe: In cold climates, check outside sections for ice. Thaw gently and insulate the pipe to prevent recurrence.
• Leak check: After reassembly, run the heater and check for leaks around the trap and connections.