Pump display shows E15, will not start, often after long idle periods

Safety first: Do not bypass insulation alarms. Risk of electric shock. Isolate power and keep area dry.

• Dry the motor: If the pump has been idle in a damp environment, allow the motor to dry in a warm, ventilated area for 24–48 hours. Do not apply external heat that exceeds motor ratings.
• Inspect cable gland: Check the motor terminal box and cable gland for cracks or loose fittings that could allow water ingress. Replace if compromised.
• Megger test (pro level): Have a technician perform an insulation resistance test between windings and earth. Compare to Lowara’s minimum acceptable values.
• Reset and test: After drying and any minor repairs, reset the alarm and test. If E15 persists, the motor insulation is likely degraded.
• When to call a pro: Motor rewinding or replacement is required when insulation resistance is too low.