Service manual

G.Fire Service Manual 28 Issue A — © Masport, March 2004
The THERMOSTAT should be mounted on a wall not too close to the heater, preferably not an
external wall which might give misleading room temperature information.
7.2 REMOVING THE CONTROL BOX.To remove the control box, extract the six pin fan
plug at the rear corner and the nine pin plug on the front of the box, withdraw one screw securing
the front of the box to the side of the firebox cabinet, pull the box toward you about 15 mm to
disengage it from the clip at its rear end. Un-clip the looms from the loom holders along the front
edge of the cabinet base and lift the control box clear. To remove it completely it is necessary to
unplug the lead to the modulator coil and take the fascia off the firebox to partially dismantle its left
lower end to release the mains cable.
TO MODULATOR
EIS WIRING DIAGRAM
REPLACEMENT
MAINS LEAD
PART No 588068
TRANSFORMER
RELAY
8
1
9
7 & 8
12
ORANGE
BLUE TO 8
NINE PIN SOCKET:
RED TO 6 PIN SOCKET
WH TO 6 PIN SOCKET
BLUE (FORK) TO 10
BRN (6.3 REC.) TO 7
BRN (4.8 REC.) TO 14
BRN (STRIPPED) TO 2
RED (STRIPPED) TO 4
Y/GN (X2) TO E
MAINS IN:
BRN TO 9
BLU TO 10
Y/GN TO E
6
5
SIX PIN SOCKET:
RED TO 9 PIN SOCKET
WH TO 9 PIN SOCKET
BROWN TO 8
Y/GN TO E
7.3 FAULT TRACING IN THE EIS SYSTEM
NOTE: These procedures carry potentially lethal risks, and they must be attempted ONLY
BY SUITABLY ELECTRICALLY QUALIFIED PERSONS.
Proceed through these steps in sequence, moving to the next after the previous ones have failed to
establish the cause of the fault.
1. NO SPARK.First check the three wires from the ignition module on the valve to the igniter
assembly. Check that they are correctly in place at both ends, and that there are no insulation faults
causing a short circuit.
2. FIRE WILL NOT LIGHT BECAUSE OF LACK OF SPARK. Isolate the heater from the mains
supply, extract the fan plug from the rear of the control box, and remove the control box from the
cabinet as detailed in 7.2.
3. Verify that the mains supply is valid and connect the heater to it.
4. Check for 230 volt supply across 9 & 10 (or across 7 & 8). If no supply, the mains lead or its
connections are faulty.
5. Turn on the FIRE switch (the top one at the left of the fascia), and check for 230 volts across 1 (or
4) and 8 (or 10). If faulty, look for fault in 9 pin socket, 5 core cable or FIRE switch.
6. Disconnect any thermostat link across terminals TS1 and TS2. Switch on at the FIRE switch and
check the voltage across TS1 and TS2. This should be approximately 24v AC. If not, the
transformer or its input or output leads are faulty.
7. Disconnect the wire on terminal 14, fit a jumper wire across TS1 and TS2, and check for 230v
across 14 and 10. If dead, the relay is probably faulty.
8. Replace the connector at terminal 14.. Switch off the mains and switch on again while checking for
230 volts across terminals 10 & 11 INSIDE THE IGNITION MODULE ON THE VALVE. If the
supply is valid but there is still no spark, the ignition module on the valve is probably faulty. If the
terminals 10 & 11 are dead, check the three core cable (and its connections) between the control
box and the ignition module on the valve.
7.4 FIRE LIGHTS BUT WILL NOT SWITCH TO HIGH FLAME.
1. Check the modulating coil resistance. This should be about 18.5k (for this model - the black one).
If open circuited, the modulating coil is faulty.