Boiler displays E14: condensate fault, causing the boiler to shut down to protect against flooding or flue blockage.

Safety first: Isolate power. Condensate is mildly acidic; wear gloves and eye protection.

• Inspect condensate trap: Locate the plastic condensate trap under the heat exchanger. Remove and clean it, flushing out any sludge and debris. Refill with clean water before refitting.
• Check discharge pipe: Follow the condensate pipe to its termination. Ensure it is not frozen, kinked, or blocked. Thaw frozen sections gently with warm cloths, not an open flame.
• Verify pipe slope: Ensure the pipe runs with a continuous fall to the drain. Correct any sagging sections that could trap water.
• Test level sensor: If fitted, check the condensate level sensor or float switch for free movement and clean it. Replace it if stuck or damaged.

When to call a professional: If the condensate system is internal to the boiler or requires re-routing, contact a heating engineer.