What to check if the solar pump is not operating?

If the pump station on a Grant Solar Thermal System is not operating, heating engineers should check for the following:

1. No electrical supply to the pump

• Controller is not calling for pump to operate
• Check power supply to controls (at fused spur)
• Check wiring to controller and pump is correct
• Check for any loose connections

2. Controller is not calling for pump to operate:

• Check controller settings and correct if necessary (please refer to instructions supplied with the Solar Controller for further support)
• Collectors may be in stagnation mode - if so, wait for the system to cool down
• Collector temperature may be too low (caused by insufficient solar radiation)
• Cylinder temperature setting may be satisfied

3. Pump is stuck

Turn off the power, locate the de-blocking screw on pump motor and rotate the motor using a screwdriver.

4. Motor capacitor failed

If this has failed, please replace the capacitor or pump motor.