Fault Finding; All Models - andrews OFS25 Installation Manual, Operation And Service Manual

FAULT FINDING

FAULT FAULT ACTION ACTION
1. BURNER WILL
NOT START
2. BURNER MOTOR
RUNS - BURNER
GOES TO
LOCKOUT
3. FUEL REACHES
NOZZLE BUT
FAILS TO IGNITE
4. BURNER LIGHTS
BUT RUNS TO
LOCKOUT
5. BURNER RUNS
BUT SMOKE
EMITTED FROM
FLUE
6. WATER
TEMPERATURE
TOO LOW
7. NOT ENOUGH
HOT WATER
8. WATER DRIPPING
FROM BASE OF
HEATER
9. RUMBLING NOISE
(KETTLING)
(a) Check electrical supply and ON/OFF switch is 'ON'.
(b) Check thermostat circuit is made and also time clock contacts
are closed and limit thermostat is set.
(c) Check if locked out. Re-set.
(d) Check continuity of burner motor windings.
(e) Check if fuel pump is seized.
(f) Replace faulty parts.
(a) Check for blocked fuel pipe, check filters in filter bowl, rear of
pump and rear of nozzle are clean, and suction pipework for air
leaks.
(b) Disconnect nozzle output pipe from fuel pump. Switch burner
on momentarily and check for delivery of fuel.
(c) If fuel not delivered from pump, check pump/motor
drive dog.
(d) If pump is turning and no fuel is delivered replace pump.
(e) Check solenoid valve is opening and trace supply from control
box.
(f) Check for blocked nozzle.
(g) Check fuel in tank.
(a) Check electrode adjustment.
(b) Check for dirty or cracked electrodes.
(c) Check HT leads and connections.
(d) Check electrical input to transformer.
(e) Replace faulty parts.
(a) Carry out checks 2-3 as above.
(b) Check that photo-cell is correctly located in holder.
(c) Check photo-cell is clean and not cracked.
(d) Replace photo-cell.
(e) Replace control box.
(a) Check fuel quality.
Fuel should be free from water and dissolved material such as
engine oil or anti-freeze.
(b) Check for blocked fuel filter or pick-up pipe.
(c) Check nozzle is tight in holder.
(d) Check burner settings.
(a) Reset the higher temperature.
(b) Check pressure at burner.
(a) Check pressure at burner.
(b) Check amount of water being used against recovery rate given
on Data Plate.
(a) Check if water stops dripping when water in heater is hot. If
water stops problem is condensation caused by incorrectly
designed flue or by tank cooling excessively i.e. more hot water
being used than recovery rate of the heater.
(b) If water continues to drip when heater is hot. Problem is a
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 problem re-occurring.
SECTION 7

ALL MODELS

27