Troubleshooting tips in RED should be done by your local professionals at Silva Mechanical.
Ignition Failure
Flame Loss
Heat exchanger overheat
Exhaust Overheat: exhaust limit sensor shuts down the unit when the flue temperature exceeds 230 °F for more than 10 seconds.
Exhaust blockage
Abnormal Cold water inlet thermistor open or short
Abnormal circulation pump ("A" models only)
Abnormal PCB communication
Abnormal input data
Abnormal input data
Abnormal outdoor temperature sensor open or short (appears only when the outdoor reset curve is enabled)
Flushing / Service alarm
Abnormal main panel communication
Abnormal flow sensor operation