Ideal Detection Lead 174787

The Ideal 174787 is a detection lead, listed by the manufacturer under the HT leads part group. It is the wiring lead that links the flame detection electrode to the appliance control board, carrying the small ionisation current the board uses to confirm a flame is present.

It is an Ideal spare supplied for the Esprit HE range of domestic gas boilers and for Ideal Commercial appliances that use the same detection circuit.

• The boiler reaches the end of its ignition sequence and then locks out, having failed to confirm a flame.
• The burner lights briefly and the appliance shuts down shortly afterwards, repeating on each attempt.
• Lockouts are intermittent rather than consistent, often appearing once the appliance has warmed up.
• The lead shows heat damage, cracked or brittle insulation, or a broken terminal at the electrode or board end.
• Continuity or resistance testing across the lead gives an unstable reading compared with the expected value.

• Match the GC number on the appliance data badge against the compatibility list, as the Esprit HE24, HE30 and HE35 use different GC numbers for the same lead.
• Confirm the part number 174787 or the alternative number 1780110 before ordering, as both identify the same lead.
• Inspect the detection electrode and its gasket at the same time, since access to the lead usually means the electrode is already removed.