andrews CSC 39 Installation Manual, Operation And Service Manual page 38

FAULT FINDING
FAULT
RUMBLING NOISE
CONTINUOUS
IGNITION
NO PILOT FLAME
PILOT LIGHTS BUT
MAIN BURNER
DOES NOT
NO IGNITION AT
PILOT
ACTION
(a) Scale formation in heater, consult water treatment
specialist. Heater must be descaled and suitable water
treatment provided to avoid re-occurrence.
(a) Check gas service cock is open.
(b) Check gas control knob is ON.
(c) Check ECO for failure.
(a) Main gas valve not energised. Check for loose contacts.
(b) Check for 24V AC at intermittent pilot ignition.
Replace control if faulty.
(c) Check for 24V AC at main gas valve terminals. Replace
valve if faulty.
(a) Electrical ON/OFF switch is not ON.
(b) Thermostat set too low.
(c) Power to unit interrupted.
SECTION 7
33