Applicable Systems
Wilo Circulator Pump
Symptoms
The Wilo pump displays alarm W009, indicating excessive motor temperature. The motor windings are operating above their insulation class limit, risking thermal degradation and failure.
Possible Causes
- Inadequate ventilation or ambient temperature exceeding motor rating
- Motor running continuously at overload current
- Blocked cooling fan or clogged cooling fins on the motor
Troubleshooting Steps
- Step 1: Measure motor winding or housing temperature
Temperature is below the insulation class limit, typically 105C for Class F - Step 2: Check motor cooling fan for damage or blockage
Fan spins freely and draws air through the motor without obstruction - Step 3: Verify the ambient temperature around the motor
Ambient temperature is within the motor's rated operating range
How to Reset
To reset: 1) Improve ventilation or reduce ambient temperature. 2) Correct any overload condition. 3) Clean the cooling system. 4) Allow the motor to cool and restart.
Source: Wilo Pump Installation and Operating Manual, Wilo SE
Category: Pump