Boiler casing or nearby area has a burnt smell during operation.

Safety first: If you smell burning, switch off the boiler immediately at the isolator and do not restart until inspected.

• Inspect internal wiring: After cooling, remove the front panel and look for discoloured or melted insulation, especially around the element terminals and contactors.
• Check terminal tightness: Tighten all accessible screw terminals on high-current paths using the correct screwdriver size.
• Examine contactors/relays: Look for signs of overheating or pitting. Replace any suspect devices.
• Clean dust: Carefully vacuum dust from vents and components without disturbing wiring.
• Professional check: If the source of the smell is not obvious, have a qualified engineer perform a detailed inspection before re-energising.