27
British Gas 4100 & 4125 RD2 -
Installation & Servicing
INSTALLATION
42 COMMISSIONING AND TESTING
WARNING.
Whilst effecting the required gas soundness test and purging air from the gas installation,
open all windows and doors, extinguish naked lights and
DO NOT SMOKE.
A.
ELECTRICAL INSTALLATION
1.
Checks to ensure electrical safety should be carried
out by a competent person.
2.
ALWAYS carry out preliminary electrical system
checks, i.e. earth continuity, polarity, resistance to
earth and short circuit using a suitable test meter.
B.
GAS INSTALLATION
1.
The whole of the gas installation, including the meter,
MUST be inspected and tested for soundness, and purged
in accordance with the recommendations of BS. 6891.
2.
Purging air from the gas installation may be expedited by
loosening the union on the gas service cock on the boiler
and purging until gas is detected.
3.
Retighten the union and check for gas soundness.
43 INITIAL LIGHTING
LEGEND
A.
Gas control valve.
B.
Burner pressure test point.
C.
Main burner pressure
adjuster.
D.
Inlet pressure test point.
E.
Gas service cock.
F.
Boiler thermostat knob.
G.
'Burner 'On' neon.
H.
Overheat thermostat reset
button.
J.
Lock out reset button.
TO LIGHT THE BOILER
1.
Check that all the drain cocks are closed and any valves
in the flow and return are open.
2.
Check that the gas service cock [E] is OPEN and the
boiler thermostat [F] is OFF.
3.
Slacken the screw in the burner pressure test point [B]
and connect a gas pressure gauge via a flexible tube.
4.
Switch the electricity supply ON and check that all external
controls are calling for heat.
5.
Press the reset button (J) and the overheat thermostat
reset button (H).
6.
Set the boiler thermostat knob [F] to position 6. The fan
will start. After the fan has run for a few seconds the igniter
will be energised. The gas valve will open and the main
burner will then cross-light smoothly. The boiler may
attempt 5 ignitions. If this fails, the boiler requires to be
manually reset by pressing the reset button. If this
sequence does not occur, refer to the Fault Finding
section.
7.
Test for gas soundness around ALL boiler gas components
using leak detection fluid.
8.
Operate the boiler for 10 minutes to stabilise the burner
temperature.
9.
The boiler is preset at the factory to its nominal rating. If
adjustment is necessary remove the sealing cap and turn the
adjusting screw [C] clockwise to increase/anticlockwise to
decrease the pressure until the required burner pressure is
achieved.
Refit the sealing cap.
10.
Set the boiler thermostat to (F) OFF.
11.
Remove the pressure gauge and tube. Retighten the sealing
screw in the pressure test point.
12.
Turn ON and check for gas soundness at the pressure test point.
13.
Refit the lower front panel and secure with the 2 fixing screws.
14.
Finally stick the appropriate British/Scottish Gas logo (supplied)
in the marked area at the top LH corner of the controls panels
door.
INST
ALLA
TION
