Ferroli F 24 B Instructions For Installation, Use And Maintenance Manual page 25

Ferroli F 24 B
Adjustment potentiometers
P1 = C.H. temperature adjustment
P2 = D.H.W. temperature adjustment
P3 = C.H. output adjustment
P4 = Ignition gas pressure adjustment
P5 = Minimum gas pressure adjustment
Adjusting maximum output for central heating system (fi g. 16)
This adjustment must be carried out electronically using the "P3" adjustment screw starting with a cold
central heating system. Connect a pressure gauge to the pressure test point downstream of the gas
valve. Rotate the temperature adjustment screw to maximum then regulate the pressure to the value
required. Once this operation is complete, start up and shut down the burner two or three times using
the thermostat. Check each time that the pressure values remain as adjusted and that the burner ignites
correctly. Otherwise further adjustment is necessary until the pressure remains stable on this value.
N.B. - when carrying out this operation ensure that the boiler thermostat is set to maximum otherwise
the adjustment will not be accurate.
Adjusting central heating fl ow temperature
Central heating water temperature is adjusted by rotating the control knob (B - fig. 1). Rotate the knob
clockwise to increase water temperature, anticlockwise to reduce water temperature. Temperature can
be varied from a minimum of 30°C to a maximum of 85°C. However, we recommend not operating the
boiler below 50°C.
Adjusting room temperature (when a room thermostat is fi tted)
Room temperature is controlled by positioning the room thermostat knob to the required value. The
thermostat automatically controls the boiler, temporarily interrupting the electrical supply subject to
the room heat requirements.
Adjusting the central heating fl ow t by varying pump fl ow-head
The thermal head t (the difference in temperature between the delivery water and return water in the
central heating circuit) must be less than 20° C. This is obtained by varying pump flow rate and head
using the multi-speed variator (or switch) on the pump itself. Increasing the pump speed reduces t and
vice versa. The minimum differential must not be less than 11°C.
Adjusting central heating system pressure
The pressure of water in the central heating system, read on the control panel pressure gauge, is adju-
sted as described in paragraph 3.08 page 24.
N.B. - To avoid incurring unnecessary expense, in the event of boiler shut down, check that this is not
caused by a lack of electricity or gas, or low water pressure before calling the Customer Technical
Service Helpline.
+
-
P5
+
-
P4
P1
- + CH
P2
- + DHW
+
-
P3
Fig. 16
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