Fan running but no ignition at electrodes Fault Fix air pressure switch hoses loose check ports and firmly fix split / kinked hoses remove kink / replace hose water in hoses (condensation) dry hoses / replace hoses reversed pressure connections (hoses wrong way around) correctly connect hoses split/punctured air pressure switch diaphragm replace air pressure switch damaged combustion chamber seals replace entire seal cracked pilot window or damaged seal replace glass / seal faulty air pressure micro switch replace air pressure switch flue / airway ducts blocked at terminal clear restrictions/blockages faulty fan (not at full capacity) check/ lubricate bearings | clear debris build up blocked / melted venturi replace fan assembly ignition electrodes cracked check / replace electrodes ignition wiring harness damaged / loose check wiring / connections faulty spark generator on p.c.b. replace p.c.b. ignition electrodes gap too far apart check gap (as per manufacturer’s instructions)…