Glow-worm Energy Saver 80 - 100 and Gave Valve - Manual (Page 32)

32 221564F
14.1 General
Replacement of parts must be carried out by a competent
person.
Before replacing any parts the boiler should be isolated from the
mains electric supply and the gas should be turned off at the
service cock on the boiler, see diagram 8.1.
Unless stated otherwise parts are replaced in the reverse order
to removal.
After replacing any parts always test for gas soundness and if
necessary carry out functional test of the controls.
For replacement of parts the front casing of the boiler will need
to be removed, see section 12.1.
14.2 Spark Electrode
Replace the spark electrode as described in section 12.4.
14.3 Ignition Lead
Pull the spark plug style connector off the spark electrode and
the spade connector connected to the top of the grey ignition
coil.
14.4 Automatic Control Module
Pull the spark plug style connector of the ignition lead off the
spark electrode.
Carefully remove the ribbon wire from the display connection on
the front face of the unit.
Undo and remove the retaining screw from the top corner of the
module.
Pull the Automatic control module forwards and upwards out of
its bracket and remove the electrical connections from the
underside of the module.
Remove the ignition lead from the module and push onto
replacement unit.
Note that the electrical connections are unique to prevent
incorrect fitting.
The Ribbon wire connection must be fitted to the lower socket
on the module marked ‘DISPLAY’.
14.5 Three Way Valve Head
Refer to diagram 14.1.
The three way valve head can be replaced as a separate item
to the body if necessary.
Depress the location button on the front of the unit.
Twist the valve head top towards the front of the boiler and
remove from the body.
Remove the electrical plug.
The replacement unit must be offered to the body in a rotated
position and pushed to the upright position on the valve body.
14.6 Three Way Valve
Refer to section 12.9 and drain the boiler heating circuit.
Remove the three way valve head as described in section 14.4.
Disconnect the Central Heating return pipe from the water cock
and loosen the clamp, see diagram 8.1.
Remove the two screws from the return pipe flange beneath the
boiler.
Remove the gas pipe.
Remove the domestic hot water pipe.
Undo the left hand nut from the bypass valve, see diagram 4.3.
Remove the pump. See section 14.14.
Undo the compression fittings on the three way valve body, pull
the return pipe down and remove the valve.
Fit the replacement valve and replace pipework.
Open the isolating valves on the flow and return connections
and refill, vent and pressurise the boiler.
Check for leaks.
14.7 Domestic Hot Water Thermistor
Refer to diagram 14.2.
Remove the three way valve head as described in section 14.5.
Remove the thermistor retaining clip.
Pull the thermistor downwards and out of its pocket.
Unclip the connecting plug and remove the thermistor.
Fit replacement thermistor ensuring that it is pushed fully into
the pocket and secure with the retaining clip.
Note that the use of a heat sink compound is not required.
Carry out a functional test of the controls.
14.8 Heating Flow Thermistor
Refer to diagram 14.3.
The heating flow thermistor is situated on the front of the
combustion chamber directly above the spark electrode.
Remove the electrical connections from the thermistor.
Undo and remove the screw and securing bracket.
Fit the replacement thermistor using the heat sink compound
supplied.
Note that the polarity of the wiring to thermistors is unimportant.
14.9 Heating Return Thermistor
Refer to diagram 14.4.
The heating return thermistor is located on the pipe running
from the pump to the heat exchanger.
Remove the thermistor clip by pulling it forwards from beneath
the pipe.
If this thermistor clip is tight it may be necessary to remove the
pump for easier access. See section 14.14.
Remove the thermistor and clip from the boiler.
Disconnect the electrical connections from the thermistor.
Push the thermistor out of its clip.
Push the replacement thermistor into the clip and apply heat
sink compound supplied.
Ensure that the thermistor is correctly located on the flat on the
return pipe and push the thermistor clip into place.
Note that the polarity of the wiring to thermistors is unimportant.
14.10 Gas Injector
Remove the injector pipe as described in section 12.3.
Undo and remove the injector from the outlet of the Gas valve,
see diagram 12.2.
Fit replacement injector into gas valve using a suitable sealant.
Do not over tighten.
14 Replacement of Parts