Sime FORMAT SYSTEM 25 HE Installation And Servicing Instructions page 18

clockwise.
7) Go to maximum power by turning
clockwise trimmer (6) as far as it will
go.
8) Adjust the trimmer (2) and check that
the Hertz value of the fan is between
172 and 176.
9) Check that C0 value is approx. 9.0%
2
for natural gas or 10.0% for propane. In
case the value would not be correct,
repeat calibration procedure as men-
tioned in point 4.
4.5 CALIBRATION PROCEDURE
IN HEATING PHASE
USING MBAR
1) Adjust air pressure (fan speed)
Connect the positive of the manometer to
the positive test point of sealed chamber (7
fig. 3).
Disconnect the SM sensor and connect a
loose one free in air, or activate the chimney
sweep function (4. 1 1).
Sequence (Fig. 20)
- Turn the heating output potentiometer to
maximum output.
- Turn the heating output trimmer B to mini-
mum.
- Adjust the minimum air pressure using
fan speed trimmer A.
- Fully open a domestic hot water tap.
- Adjust the maximum air pressure using
fan speed trimmer D (2 fig. 20).
AIR PRESSURE
Minimum
(mm H O)
2
13
2) Adjust gas pressure
Connect the positive of the manometer to
the gas test point (6 fig. 3).
Sequence (Fig. 20)
– Turn heating output potentiometer to
maximum output.
– Turn the heating power trimmer B to
minimum.
– Fully open the gas valve shutter (7).
– Adjust the gas pressure using the OFF-
SET (8) to obtain the figure in mmH
shown in the table:
GAS PRESSURE
G20
(mm H O)
2
12
– Close the gas valve shutter (7) to
obtain the figure in mmH
the table:
GAS PRESSURE
G20
(mm H O)
2
10.5
18
KEY
2
4
6
7
8
CO VALUE %
2
Minimum output
Maximum output
- To adjust CO
gas valve OFF-SET.
- To adjust CO
gas valve shutter.
Maximum
Very important: It's not necessary to adjust
(mm H O)
2
the gas pressure or the fan speed should
93
the boiler be converted to another gas (ie
natural gas to LPG) only the injector will
require changing.
4.6 GAS CONVERSION
A kit complete with instructions for transforma-
tion is supplied for G31 propane gas conversion.
O
2
G31
(mm H O)
2
13
O shown in
2
G31
(mm H O)
2
12.5
MAX fan speed trimmer
MIN fan speed trimmer
Heating power trimmer
Shutter
OFF-SET
7
Natural gas LPG
8.7/9.3 9.7/10. 1
8.7/9.3 9.7/10. 1
at maximum output adjust the
2
at minimum output to ajust the
2
1
2
6 4
8
4.7 DISASSEMBLY OF
EXPANSION VESSEL
To disassemble the expansion vessel, pro-
ceed as follows:
– Make sure that the water has been emp-
tied out of the boiler.
– Unscrew the connection and the locknut.
– Remove the expansion vessel.
Before refilling the system, using a pres-
sure gauge attached to the valve make sure
that the expansion vessel is preloaded at a
pressure of 0.8 to 1 bar.
4.8 REMOVAL OF OUTER
CASING
It is possible to completely disassemble the
shell for an easy maintenance of the boiler
as showed in fig. 21.
2
Fig. 20
Fig. 21