42
12.6 Range Rating
These boilers are fully modulating, therefore it is not
necessary to range rate them, however, if desired, you can
adjust the output in 1kW increments between:
18sx : 10 - 18kW
30sx : 10 - 30kW
as follows:
a) Press and hold the ‘MODE’ and “+” button for 5
seconds. The display will change to ashing ‘0’.
b) Use the ‘+’ or ‘-’ button to scroll to 96.
c) Press ‘MODE’ and hold 5 seconds to conrm.
d) The display now shows a ashing ‘d. 0’.
e) The part load setting is displayed in kW.
Press ‘MODE’ the max rate will be indicated, to
change the value to the desired setting, use the ‘+’
or ‘-’ button.
f) Press ‘MODE’ for 5 sec to conrm the new setting
has been saved.
g) Press and hold ‘MODE’ and “+” to exit.
Please refer to the table below to check the gas rates.
12.7 Testing - Heating System
Check that all external controls are calling for heat, the boiler
will re automatically. Fully open all radiator valves and ow
control valve ‘A’, if tted, see diagram 5.1.
Balance the radiators as required and if tted adjust valve ‘A’
to give the required system differential. Turn off all radiators
that can be shut off by the user and check to see if less than
the maximum differential allowed of 20°C can be achieved
across ow and return.
The pump has two speeds and can be adjusted depending on
the requirements of the central heating system, see diagram
5.2.
The appliances have an inbuilt automatic adjustable bypass
valve, see diagram 12.4. The pressure can be adjusted
between approx. 1.5 and 3.5mH
2
O.
The bypass is factory pre-set to approx. 2.5mH
2
O. The
pressure changes by approx. 0.1mH
2
O for each full turn
of the bypass screw, see diagram 12.4. Turning clockwise
increases the pressure and turning anti-clockwise decreases
the pressure.
Allow the system to reach maximum temperature then switch
off the boiler by isolating from the electrical supply.
Drain the entire system rapidly whilst hot, using the drain tap
at the lowest part of the system. Fill and vent the system as
described previously in section 12.1.
Lock or remove the handle from control valve, if tted.
12 Commissioning
12.8 Completion
Adjust the boiler temperature control and any system controls
to their required settings.
GB: It is a requirement that the “Benchmark” Installation,
Commissioning and Service Record is completed and left with
the user.
IE: it is necessary to complete a “Declaration of Conformity” to
indicate compliance to I.S.813. An example of this is given in
the current edition of I.S.813.
12.9 Instruct the User
● Demonstrate, then instruct the User about the lighting
procedure and heating system controls operation.
● Advise that to ensure the continued efcient and safe
operation of the boiler it is recommended that it is checked
and serviced at regular intervals. The frequency of servicing
will depend upon the installation conditions and usage, but in
general, once a year should be enough.
● Draw attention, if applicable, to the current issue of the Gas
Safety (Installation and Use) Regulations, Section 35, which
imposes a duty of care on all persons who let out any property
containing a gas appliance in the UK.
● The user shall not interfere with or adjust sealed
components.
● It is the Law that any servicing is carried out by a
competent person approved at the time by the Health and
Safety Executive.
● Advise the user that, like all condensing boilers this
appliance will produce a plume of condensation from the ue
terminal in cool weather. This is due to the high efciency and
hence low ue gas temperature of the boiler.
● Advise the user of the precautions necessary to prevent
damage to the system, boiler and the building, in the event of
the heating system being out of use during frost or freezing
conditions.
● Advise the user that the permanent mains electrical supply
SHOULD NOT be switched off, as the built in frost protection
and pump saver program will not operate.
● Advise the User if the mains electricity and gas are to be
turned off for any long periods during severe weather, it is
recommended that the whole system, including the boiler,
should be drained to avoid the risk of freezing.
NOTE: Sealed System: Contact your installation/servicing
company as draining, relling and pressurising MUST be
carried out by a competent person approved at the time by
the Health and Safety Executive.
● Leave these instructions and the ‘Benchmark’ Installation,
Commissioning and Service Record with the user.
kW m3/hr ft3/hr kW m3/hr ft3/hr
20 2.1 74.2
30 3.2 113 19 2.0 70.6
29 3.1 109.5 18 1.9 67.1
28 3.0 106 17 1.8 63.6
27 2.9 102.4 16 1.7 60.0
26 2.8 98.9 15 1.6 56.5
25 2.6 91.8 14 1.5 53.0
24 2.5 88.3 13 1.4 49.5
23 2.4 84.8 12 1.3 45.9
22 2.3 81.2 11 1.2 42.4
21 2.2 77.7 10 1.1 38.9
13073
Diagram 12.4