installation
The system should again be filled, cleared of air locks
and examined for water soundness.
Add inhibitor to the system if required in the specification (see 5.9 .)
6.3.2.
Sealed System Only
The whole of the system should be ffied and thoroughly
flushed out with cold water without the circulating pump
in position. Ensure that alI valves are open. (The system
must be filled with water either from a sealed system filler
pump with a break tank. or by any other method approved
by the local Water Undertaking)-
With the circulating pump fitted, the system should be
filled and air locks cleared until the pressure gauge registers
1.5 bar (21 .S Ibf/in2). (The boiler water section can be
vented if necessary by unscrewing the knuried nut on the
drain valve, see 6.6). Vent all radiators and check for water
soundness.
Manually raise the water pressure to ensure that the safety
valve lifts. This should occur within f 0.3 bar (’ 4.3
Ibf/i.n2) of the preset lift pressure. i.e. 3 bar (43.5 Ibf/in2).
Release water from the system until the initial system
design pressure is attained, taking into account any difference in height between the pressure gauge and the point at
which the pressure vessel is connected.
Light the boiler as detailed in 6.4.
The water system should be heated to maximum working
temperature and examined for water soundness. Both
gas and water should then be turned off and the water
system rapidly drained whilst still hot.
The system should again be filled, cleared of air locks
and adjusted to the initial system design pressure. Any
set pointer on the pressure gauge should be set to coincide
with the indicating pointer- Examine for water soundness.
Add inhibitor to the system if required in the specification (see 5.9.).
6.4.
Lighting the Boiler
The following procedure should be followed :
(4
(b)
Cc)
‘N.B.
(4
(e)
0-l
(ia
Check that the gas service tap is open.
Replace the gas control knob.
Turn the gas control knob in an anticlockwise
direction which will automatically light the pilot.
It may be necessary to wait a few moments for
gas to reach the pilot.
Wait 15 seconds, then turn the gas control knob
slowly, fully, in an anticlockwise direction. If
pilot is extinguished for any reason, wait 3 minutes
before lighting.
The boiler is now ready to operate and will light
when water is pumped through.
Test for gas soundness using sense of smell and
leak detection fluid.
Check and, if necessary, adjust the gas rate as
detailed in 6.5.
6.5. Gas Rate Adjustment
The
boiler is not
fitted
with a governor.
To obtain the required output, it may be necessary to
change the restrictor situated in the burner manifold
(fig. 17). To alter the heat output remove the pilot supply
tube and the two screws securing the burner manifold to
the burner assembly. Replace the restrictor with the required
size as detailed in TECHNICAL DATA. Replace the burner
manifold and pilot tube.
Since the opening of the gas valve depends upon water
flow rate, make the above adjustment when all the air
is removed from the system and all radiator valves are
fully open.
Mark the data badge in the line “SET TO” (against output)
to which the boiler has been adjusted- The data badge is
situated inside the case.
6.6.
Balancing the System By-Pass
The system by-pass should be balanced as the final part
of commissioning.
1.
A system by-Pass is not required for the safe
operation of the boiler, which will automatically
shut down if the flow rate drops below 500 l/h
(1.85 gpm). If however the system may be required
to be used with a large reduction of heat output at
certain times i. e. a reduced number of radiators,
then a 15 mm system by-pass should be used. This
should be fitted as shown in diagram 6. To set the
system by-pass, close the by-pass valve and turn
off the required number of radiators to suit the
customer’s needs then open the by-pass until the
boiler lights.
2.
Check system on hot water only. Open bypass
further if necessary to obtain correct operation.
6.7.
Draining the Boiler
Close the valves in the pipework connecting the boiler
to the system (fig. 13 or 14). Drain the boiler unscrewing
the knurled nut on the drain valve.
7) BOILER CASE ASSEMBLY
7.1. Balanced Flue Version
Fit front cover and refit securing screws at the top and
bottom and immediately under the gas control.
Push on gas control knob.
7.2.
Open Flue Version
Fit case and refit securing screw immediately under the
gas control. Push on gas control knob.
Hand the USERS INSTRUCTIONS to the user for reten-
tion and instruct in the operation of the boiler.
Advise the user of the precautions necessary to prevent
damage to the system and to the building in the event of
the system remaining inoperative during frost conditions.
Finally advise the user that, for continued efficient and
safe operation of the boiler, it is important that adequate
servicing is carried out at regular mtervais recommended
by the local Gas Region.