The display shows E15; the heater may not start or may shut down when the internal temperature is high.

Safety: Turn off the power before removing covers.

Steps:

• Check installation: Ensure the Eldom heater has adequate clearance around it, as specified in the manual. Do not enclose it in a sealed cabinet without ventilation.
• Remove heat sources: Make sure there are no heaters or hot air ducts blowing directly onto the unit.
• Inspect internal sensor: Some models have a small NTC or thermal switch on the control PCB or inside the control housing. Check that it is not covered with insulation or debris.
• Clean dust: Gently remove dust from the control compartment to improve heat dissipation.
• Replace sensor or PCB: If E15 appears even at normal ambient temperature, the internal sensor or PCB may be defective and require replacement.