Ideal Wiring Harness Mechanical Timer 175903

This is the wiring harness that links the mechanical timer to the rest of the control circuit on Ideal appliances. It is manufactured by Ideal and supplied under part number 175903, with alternative number 1781562 also used to identify the same item. The harness carries the switching signals from the timer through to the boiler controls, so the appliance responds correctly to the programmed on and off periods.

• The mechanical timer fails to switch the appliance on or off at the set times
• Heating or hot water runs continuously, or does not come on at all, despite the timer dial moving
• Intermittent operation where the appliance drops out partway through a timed period
• Visible damage to the harness, such as chafed insulation, scorching or a broken conductor
• Loose or poor contact at the timer plug or the control board connector

• Check the appliance GC number and model against the compatibility list, as the same appliance family can use different harness layouts
• Confirm the part number on the existing harness or timer assembly before ordering
• Note the alternative number 1781562, which may appear on older stock or documentation
• Work on the appliance controls should be carried out by a competent person, with the electrical supply isolated before the harness is disconnected