Fault Finding - andrews 10/105 Installation And Service Manual

7

Fault Finding

7.1 Fault Finding
Fault
NO IGNITION
AT PILOT
FLUE FAN RUNS NO
IGNITION SPARK
FLUE FAN DOES
NOT RUN
HEATER WILL NOT
LIGHT LOCKOUT
ALARM ILLUMINATED
MAIN BURNER
OUTAGE AT
PERIODIC INTERVALS
WATER
TEMPERATURE
TOO HIGH
WATER
TEMPERATURE
TOO LOW
NOT ENOUGH
HOT WATER
WATER DRIPPING
FROM BASE OF
HEATER
RUMBLING NOISE
Action
(a) Power to unit interrupted
(b) Thermostat faulty
(c) Spark ignition control module faulty
(a) Faulty air pressure switch
(b)
Faulty spark ignition lead
(a)
Power to unit interrupted
(b) Faulty fan motor
(c)
Flue fan ECO actuated
(a) Check gas service cock is open Press reset button Check action of flue fan ECO. If this switch is
Actuating check:
(a) Sufficient ventilation is provided
(b)
The resistance of the flue system is to high
(c) The burner pressure is to high
(d)
The flue fan ECO is faulty
(a) Reset thermostat to lower temperature.
(b)
Thermostat faulty. Check and replace if necessary.
(c) Main gas valve not closing. Clean or replace.
(a) Reset thermostat to higher temperature.
(b)
Check gas pressures at burner and at gas inlet to heater.
(c) Thermostat faulty. Check and replace if necessary.
(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.
Fault Finding 7
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