My Halstead Best 60 was working fine last night. This morning, no heat or hot water and the “Ignition Lockout” light is on. Resetting in accordance with mfr’s instructions causes fan to start…and then the lockout light comes on again after a few seconds (and the fan stops). Almost exactly a year ago the Aquastat PCB failed – presumably unrelated. Is the most likely problem a failed Ignition Device or is there something else I should check first? The fault finding chart is not over-helpful. Thanks in advance for any help/suggestions.