V

Tip: Check the ceramic insulator is not damaged, this can cause the spark to earth, twist and pull the ceramic insulator to ensure it is not broken.
▶ Check the gas supply to the property and the inlet on the gas valve.
▶ Check for low pressure when the gas valve opens.
▶ Gas valve failing to open: check for voltage to the valve and for possible blockage on inlet filter of the gas valve.
▶ Obstruction in the air intake to the fan leading to incorrect CO2 ratio.
▶ Condensate siphon is blocked or restricted. Condensate pipe is frozen.
▶ Flue is blocked or restricted.
▶ Heat exchanger is blocked or restricted.
▶ Check the burner for damage.
▶ Check the spark electrode/lead for failure.
▶ Check the flame sense/lead for failure.
▶ Check the rectification ground (black wire to heat exchanger).