Test the motor windings for resistance, and perform an insulation resistance (megger) test from each motor phase to earth.
Black - Primary Winding
Red - Secondary Winding
Green - Common

Resistance is lower for higher powered motors, usually a few ohms for the primary winding and about 3 times higher for the secondary winding. A zero or very high resistance is a fail.

Insulation resistance should exceed 3 megohms.
This troubleshooting guide is primarily intended for technicians and competent persons only for resolving problems with the SteelPumps range. If you do not understand any of the terms within the guide or get stuck please send an email with photographs of your installation to sales@steelpumps.co.uk. You can also contact us for advice on 01239 623506, but please be aware that we may have to call you back when an Engineer is available.
Important warranty information
Your two year Warranty is not valid if the pump has been disassembled in any way.

The Warranty does not cover malfunctioning due to a failure to properly install or commission the pump in accordance with the installation instructions. Correct installation is particularly vital in the case of automatic pumps which will run excessively if the pressure drops in the delivery network.

How to initiate a warranty claim.