
DOMINA 80 E
42
5.04 Adjusting maximum output for central heating system
(fig. 33)
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, consulting the diagram
(figs. 4 and 5) (page 8).
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.
Fig. 33
5.03 Adjustment potentiometers
P1
= C.H. temperature adjustment
P2
= D.H.W. temperature adjustment
P3
= C.H. output adjustment
P1
P2
P3
On the main P.C.B.
P4
P5
On Ignition Board
P4
= Ignition gas pressure adjustment
P5
= Factory set - Don't touch
5.05 Adjusting central heating flow temperature
Central heating water temperature is adjusted by rotating the control knob (fig. 2 - part 63). 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.
5.06 Adjusting room temperature
(when a room thermostat is fitted)
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.
5.07 Adjusting the central heating flow
∆
t by varying pump flow-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.