28
SECTION 3 - SERVICING
1.
Refer to Frame 3.8.
2.
Drain the heating system. Refer to Frame 3.21.
3.
Unscrew the pressure gauge and discard.
4.
Fit new pressure gauge using a suitable jointing
compound.
5.
Refill the boiler with specified anti-freeze.
6.
Check operation of the boiler.
3.23 PRESSURE GAUGE RENEWAL
3.21 DRAINING THE BOILER
DOMESTIC HOT WATER CIRCUIT
1.
Refer to Frame 3.8.
2.
Close the DHW water isolating valve on the boiler inlet.
3.
To drain the domestic hot water circuit: As there is no direct drain for the domestic hot water circuit, depending on the
location of the boiler, opening the lowest hot water tap may drain this circuit. However it must be noted that some residual
water will be experienced during replacement of components.
4.
After replacing any component on the boiler, close tap, close the drain valve and open all system isolating valves (re-
pressurise as appropriate)
5.
Check operation of the boiler.
CENTRAL HEATING CIRCUIT
1.
Refer to Frame 3.8.
2.
Close all the CH water isolating valves on the boiler inlet.
3.
To drain the primary heat exchanger circuit: Open the drain
valve and attach a length of hose to the CH drain point.
4.
After replacing any component on the boiler, remove the hose,
close the drain valve and open all system isolating valves (re-
pressurise as appropriate).
5.
Refill with specified antifreeze.
6.
Check operation of the boiler.
CH
Flow
DHW
Inlet
DHW
Outlet
Gas
CH
Return
CH
Circuit
Drain
3.22 DHW FLOW TURBINE SENSOR REPLACEMENT
1.
Refer to Frame 3.8.
2.
Drain the DHW system. Refer to
Frame 3.21.
3.
Pull off the electrical connection.
4.
Using a suitable tool, lift and
remove the retaining clip.
5.
Use the clip to ease the turbine
sensor from its housing.
6.
Re-assemble in reverse order.
7.
Check operation of the boiler.
4
3
5
Summary of Contents for GB24
Page 43: ...43 NOTES ...
