The service department was getting a lot of returned boiler units from customers due to power cut outs. The issue was handed to myself to investigate. I found that 2 of the wires leading from the on/off switch were bent 90° to the boiler. This created a concentrated point on the wire which was susceptible to heat build up as it was in close proximity to the heating element. The result was after a duration of use the wire melted and power was lost to the unit. To stop this, it was suggested using 90° flag terminals to prevent the bend in the wire. The prototype unit was then put on a continuing cycle to see how long if at all the wires took to fail. The wires did not fail so the change was implemented to all current and future designs.
