Remedy
▶ Check the gas supply to the property and the inlet on the gas valve (check drop on inlet) and replace if required.
▶ Check the flame sense probe and the ignition transformer to the heat exchanger.
▶ Check the voltage to the gas valve and the continuity of harness and replace if required.
▶ Check the condition of the bearing plate and back-flow prevention valve between the fan and the burner.
▶ Check the flame sense plug is connected and the continuity of harness and replace if required.
▶ Check the condensate trap and the discharge route.
▶ Check the flue integrity (→ Chapter 9.6, page 54).