Supplied By www.heating spares.co Tel. 0161 620 6677
39
221474C
Diagram 4.7
PRESSURE
GAUGE
CONNECTION
SAFETY
VALVE
SEALING
WASHER
SECURING
SCREW (2)
PRESSURE GAUGE
PRESSURE
GAUGE
BRACKET
2831
4 Replacement of Parts
Diagram 4.6
ELECTRICAL
CONNECTORS
BOILER
PROTECTION
THERMOSTAT
SECURING
SCREW (2)
6377
4.12 Boiler Protection Thermostat
Remove the pump, see Section 4.11.
Disconnect the electrical connectors at the domestic hot water high
limit control, see diagram 4.6.
Remove the high limit control from the flow pipe, secured with two
screws.
When refitting the electrical connections to the high limit control the
polarity is not important, see diagram 4.11.
Use the heat sink compound supplied, between the mounting plate
and the control.
4.13 Pressure Gauge
Remove the control housing assembly, see diagram 4.1.
Release the water pressure and drain the central heating circuit of
the boiler, refer to Section 1.3 and 1.6.
Remove the pressure gauge bracket.
Disconnect the pressure gauge connection from the safety valve,
discard the washer, see diagram 4.7.
Remove the pressure gauge secured with the retaining tabs.
Locate the supplied new washer under the pressure gauge
connection when refitting the safety valve.
4.14 Control Boards
CAUTION. Great care must be taken when handling any control
board.
THE MAIN CONTROL BOARD MUST BE KEPT IN THE ANTI
STATIC HOLDER UNTIL NEEDED.
Note. Timer/clock may be removed to improve access, see Section
4.32 or the control housing bottom half can be removed.
Main Control Board
Remove control housing cover securing screw, see diagram 4.8.
Remove the control housing assembly as shown in diagram 4.1.
Lift the control housing cover to gain access to the board.
Disconnect all multipin connectors, see diagram 4.8.
Remove the control board from the support posts.
To reconnect the multipin connectors correctly, see diagram 4.11.
When replacing the main control board check and adjust the main
burner gas pressure in both the domestic hot water and central
heating modes. Check also minimum burner pressure. Refer to
“Commissioning” in the Installation Instructions.
Fan Driver Board
Remove the fan driver control housing assembly securing screws.
Remove the multipin connectors, see diagram 4.9.
Release the board from its support posts then remove the nut and
screw securing the board to the cover, see diagram 4.9.
User Control Board
Remove the fascia, see diagram 4.8.
Remove the multipin connector.
Remove the control board from the supports posts.
