andrews 24/39, Installation Manual, Operation And Service Manual

Page: 46 / 96

46
FAULT FINDING SECTION 8
ALL MODELS
FAULT ACTION
HEATER SOOTING, (a) Check gas burner pressure and injector size. If possible,
YELLOW FLAME check heat input with meter and watch.
(POOR COMBUSTION) (b) Clean burners and injectors.
(c) Flue obstruction. Clean flue ways.
(d) Check flue design and termination position.
(e) Check for correct ventilation.
WATER TEMPERATURE (a) Reset thermostat to lower temperature.
TOO HIGH (b) Thermostat faulty. Check and replace if necessary.
(c) Main gas valve not closing. Clean or replace.
WATER TEMPERATURE (a) Reset thermostat to higher temperature.
TOO LOW (b) Check gas pressures at burner and at gas inlet to heater.
(c) Thermostat faulty. Check and replace if necessary.
NOT ENOUGH (a) Check gas pressures at burner and at gas inlet to heater.
HOT WATER (b) Check amount of water being used against recovery rate
given on data plate. If usage too high, more heating
capacity needed.
WATER DRIPPING (a) Check if this stops when water in heater is hot. If yes, then
FROM BASE OF condensation is the problem caused by incorrectly designed
HEATER 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.
RUMBLING NOISE (a) Scale formation in heater, consult water treatment
specialist. Heater must be descaled and suitable water
treatment provided to avoid re-occurrence.