40
– isolate the gas cock
– loosen the screw of the "mains pressure" point (6) and con-
nect a pressure gauge
6
Fig. 40
– open the gas cock
– power the boiler by setting the main switch to "ON"
– press the button
s
until "SUMMER" mode
l
has been se-
lected
– press and hold down the buttons
o
and
>
at the same time
for approximately 10 seconds until the message “Hi” appears
on the display together with the flashing symbols
l
and
n
– press the button
>
to make the boiler operate at maximum
power "Hi" and check that the mains gas pressure value on
the pressure gauge is correct.
– press the button
<
to make the boiler operate at minimum
power "Lo". The message
"Lo"
will appear on the display to-
gether with the flashing symbols
l
and
n
– press the button
s
to exit the "Chimney sweep Procedure”.
The boiler water delivery temperature will appear on the dis-
play
– disconnect the pressure gauge, carefully close the pressure
point (6), test for gas tightness, put the control panel back to
the original position and refit the front panel (2). Now conduct
a flue gas analysis as detailed in APPENDIX 2
– ensure the required information is recorded in the Gas Boiler
System Commissioning Checklist( Benchmark).
Gas supply pressure
Type of gas
G20
G31
Pressure (mbar)
19
36
NOTE: There are negligeable losses of working gas pressure
attributable to the boiler as the gas cock is connected directly
to the gas valve.
7.7
Gas conversion
Murelle Pro HE MkII
models can work with G20 or G31 without
the need for any mechanical conversion. Simply select parame-
ter
"0.3"
(see "Parameter setting and display" page 37) and set
the type of gas to be used.
If changing the type of gas to be used, carry out the entire ap-
pliance
"COMMISSIONING"
m
CAUTION
If the gas supply is changed from G20 to G31, mark
the box on the TECHNICAL DATA PLATE.
X
G31 - 36 mbar
7.8
Heating power output adjustment
To comply with Building regulations, the heating output must
be set according to the requirements of the installed heating
system.
This is done by adjustment of "parameter 15" (tS 1.5).
Calculate the heating requirements of the heating system in
kW. Determine what that value is, as a % of the nominal heat
output of the boiler, see table "Technical features" page 19.
Access the parameters as shown in "Parameter setting and
display" page 37, and adjust the parameter 15 (tS 1.5) to that
% value
Example:
–
Heating system with 8 radiators, average 1.5 kW per radiator
total heat
–
Requirement 12 kW (8 x 1.5)
–
Maximum nominal heat output of boiler = 23.6 kW
–
Parameter 15 (tS 1.5) = 12/23.6 = 50.8%. Set tS 1.5 to 51%.
m
CAUTION
As a condition of the warranty and to ensure correct
operation and efficiency, it is important that the boiler
is serviced every 12 months, within 30 days of the an-
niversary of the installation date ensure the required
information is recorded in the Gas Boiler System Ser-
vice Interval Record (page 46) (Benchmark).
