Potterton Ignition Transformer ZAG 2/230 V 972789

The Potterton Ignition Transformer ZAG 2/230 V is a mains-voltage ignition transformer used in Potterton Commercial Paramount gas boilers. It steps up the 230 V supply to produce the high-voltage spark that lights the burner at start-up. The part carries the Potterton part number 972789 and is listed against the replaced code 927789.

• The boiler attempts to fire but no spark is produced at the ignition electrode
• Repeated lockouts on start-up with no flame established
• The burner lights intermittently or fails to light at all despite a healthy gas supply
• Visible burning, cracking or arcing damage on the transformer body or its terminals
• No high-voltage output measured at the transformer secondary when the boiler calls for heat

• Confirm the boiler model and kW rating against the fit list above
• Check the part number on the existing transformer matches 972789 or the replaced code 927789
• Inspect the ignition electrode, leads and insulation for damage, as a failed lead can mimic a transformer fault
• Isolate the electrical supply to the appliance before removing or testing the transformer