gledhill GC2000/120/E-OV Design, Installation & Servicing Instructions page 41

BOILER OVERHEAT THERMOSTAT - REMOVAL
Remove screw on cover (counter clockwise) at the front of the thermostat. Remove
the central fixing nut. Remove (pull off ) the leads from the back.
Remove the split pin at the thermostat phial pocket and pull out the phial.
Remove the thermostat, capillary and phial through the top of the casing.
Exchange if necessary and re-assemble in reverse order.
Finally depress thermostat reset button before fitting cover.
Check boiler/controls operation.
PRESSURE GAUGE REMOVAL
Isolate the appliance from the heating system. Turn off supply to auto-make up
tank if fitted. Open the safety valve to release internal boiler pressure. Drain down
the boiler to below the level of the safety valve. Unscrew (counter clockwise) the
capillary at the valve. Remove the knurled nut at the back of the gauge and pull
the capillary out through the panel.
If necessary exchange and re-assemble in reverse order.
Refill the boiler ensuring all air is removed.
UNDERTAKE WATER SOUNDNESS TEST.
Check boiler/controls operation.
SAFETY (PRESSURE RELEASE) VALVE
Isolate the appliance from the heating system. Turn off the supply to any auto
make up tank if fitted. Open the safety valve to release any internal pressure. Drain
down the boiler to below the level of the safety valve.
Operate the valve once more to remove residual water and disconnect the capillary
of the pressure gauge from the valve.
Disconnect the valve discharge pipe and unscrew (counter clockwise) the valve
from its mounting. If necessary exchange the valve and re-assemble in reverse
order.
Refill the boiler ensuring all air is removed.
when full operate the valve and ensure that at normal operating pressure (1.0 -
1.2) bar cold, the valve is water tight.
Check boiler/controls operation.
EXPANSION VESSEL - REMOVAL
Isolate the appliance from the heating system.
Turn off the supply to any auto-make up tank if fitted. Open the safety valve to
release any internal pressure. Drain down the boiler to below the level of the safety
valve. Remove all residual water possible through safety valve discharge.
Disconnect the flexible pipe from the front of the expansion vessel and pull the
vessel forward out of its recess. DO NOT MISPLACE THE SEALING WASHER.
Exchange the vessel if required and re-assemble in reverse order.
Refill the boiler ensuring all air is removed.
UNDERTAKE WATER SOUNDNESS TEST.
Check boiler/controls operation.
FASCIA MOUNTED SELECTOR SWITCH PCB - REMOVAL -
SWITCH FACILITY
Remove terminal/block plugs (3) at rear of pcb.
Remove control knob - (allen key headed grub screw at back of knob).
Remove single nut fixing behind control knob and remove PCB complete with
reset button.
Replace if necessary and re-assemble in reverse order. Replace any severed
cable ties.
Check boiler/controls operation.
Supplied By www.heating spares.co Tel. 0161 620 6677
COMPONENT EXCHANGE
RESET BUTTON
Disconnect single nut fixing from reset button
and push it through hole in panel. Replace if
necessary and re-assemble in reverse order.
Check boiler/controls operation.
TIMER - REMOVAL
Pull off transparent protective cover.
Remove push on connectors at rear of timer
body.
Release screw catches at front (top LH and
bottom RH).
Pull timer forward to release from panel.
Replace if necessary and re-assemble in reverse
order.
Check boiler/controls operation.
FAN CONTROL PCB - REMOVAL
Remove the two ribbon connector plugs from
the PCB.
Lift the PCB off its supports (4).
Replace if necessary and re-assemble in reverse
order.
Check boiler/controls operation.
MAIN 'ACB' PCB - REMOVAL
Pull off the terminal/block plugs (4) at the edge
of the PCB.
Remove the ribbon connector plug in the centre.
Lift the PCB off its supports (8).
Replace if necessary and re-assemble in reverse
order. Ensure jumper positions are correct.
(see figure 23).
Check boiler/controls operation.
PHE SENSOR (PLATE RETURN) -
REMOVAL
Isolate the boiler from the heating system.
Turn off the supply to any auto-make up tank,
if fitted. Open the safety valve to release any
internal pressure. Drain down the boiler.
Identify the appropriate cable connections at
the main PCB. Disconnect the sensor cables.
Cut any cable ties necessary to strip out the
cable back to the sensor head.
NOTE:If the PHE sensor is to be replaced remove
the electric boiler cover (if fitted).
Remove fixing screws (2) at top and under side
of cover.
Unscrew sensor (counter clockwise) - replace if
necessary. Re-assemble in reverse order.
Replace cable ties.
UNDERTAKE WATER SOUNDNESS TEST.
Check boiler/controls operation.
Page 41