Ferroli F24
27
• Check that the gas valve modulates correctly both during the central heating phase and the domestic
hot water production phase.
• Determine the combustion efficiency and the composition of the flue gases (refer to 6.04)
• If any of the above are not correct refer to Technical Data (page 5). Adjustment (refer to 5) and Fault
finding (page 39).
5. ADJUSTMENT AND GAS CONVERSION
5.01 Adjusting the pressure and fl ow rate to the main burner
This boiler operates on the flame modulation principle. It has two fixed pressure values, minimum and maximum,
which must be as shown in the table (pages 5), whichever type of gas is used.
Note -
Because correct minimum and maximum pressures are critical to the efficient operation
of the boiler it is ESSENTIAL that the following adjustments are carried out by COMPETENT
personnel ONLY.
5.02 Adjusting minimum and maximum pressure
Honeywell V K4105G gas valve
- Connect suitable pressure gauge to burner test
point “
B
” downstream of the gas valve.
- Disconnect the pressure compensation tube
«
F
».
- Remove the protective cap «
C
».
- Adjust potentiometre
P3
(on the main board) at
minimum (clockwise).
- Operate boiler for central heating
- Adjust minimum pressure by rotating screw «
D
»
clockwise toreduce pressure and anticlockwise to
increase pressure.
- Adjust potentiometre
P3
at maximum (anticloc-
kwise)
- Adjust max pressure by rotating screw «
E
», cloc-
kwise to increase pressure and anticlockwise to
reduce pressure.
- Reconnect the pressure compensation tube «
F
».
- Replace protective cap «
C
».
M Minimum possible gas pressures are
now set. Range Rating the central heating is not
IN
OUT
C
F
E
B
A
D
Key
A =
Gas inlet test point
B =
Gas outlet test point
C =
Protection cup
D =
Min. pressure adjusting screw
E =
Max. pressure adjusting screw
F =
Balancing tube
Fig. 28
