Fault Finding - andrews CSC39 Installation Manual, Operation & Service Manual

FAULT FINDING

FAULT
WATER DOES
NOT GET HOT
HEATER SOOTING,
YELLOW FLAME
(POOR
COMBUSTION)
WATER
TEMPERATURE
TOO HIGH
NOT ENOUGH
HOT WATER
WATER DRIPPING
FROM BASE OF
HEATER
RUMBLING NOISE
CONTINUOUS
IGNITION
NO PILOT FLAME
PILOT LIGHTS BUT
MAIN BURNER
DOES NOT
NO IGNITION AT
PILOT
ACTION
(a) Check gas service cock is open.
(b) Check water valves are open.
(c) Check thermostat setting. (reset to higher temperature)
(a) Check gas burner. If possible, check heat input with meter
and watch.
(b) Clean burners and injectors.
(c) Flue obstruction. Clean flue ways.
(d) Check flue and termination position.
(e) Check for correct ventilation.
(a) Reset thermostat to lower temperature.
(b) Thermostat faulty. Check and replace if necessary.
(c) Main gas valve not closing. Clean or replace.
(a) Check gas pressures at burner and at gas inlet to heater.
(b) Check amount of water being used against recovery rate
given on data plate. If usage too high, more heating
capacity needed.
(a) Check if this stops when water in heater is hot. If yes, then
condensation is the problem caused by incorrectly designed
flue or by tank cooling excessively, i.e. more hot water
being used than recovery rate of heater. If so, more
heating capacity needed.
(b) If water continues to drip when heater is hot, problem is
leaking joint or storage vessel.
(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
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