Alpha InTec 26C Installation And Servicing Instructions page 25

Frost Thermostat
The boiler incorporates a built in frost thermostat which automatically turns on the boiler and pump if the water in the boiler
falls below 4°C, providing the electrical supply is on and the boiler is in standby mode. The boiler will operate until the water
temperature in the boiler reaches 30°C.
Any other pipework outside of the boiler must be protected from the risk of freezing and insulated. Additional protection from
an external frost thermostat and pipe thermostats should be considered.
Pump Cycle
If the electrical supply is on and the boiler has not operated for 24 hours in heating or hot water, the pump will operate
automatically for thirty seconds every 24 hours.
5.6 CHECK THE BURNER PRESSURES - Figs. 26 and 27
Press and hold in the reset button for eight seconds and the boiler will fire at a fixed output depending on the position of the
boiler central heating thermostat knob.
Turn the boiler central heating thermostat to maximum to check the maximum central heating burner pressure.
With the boiler central heating thermostat set to maximum fully open a hot tap to check the maximum domestic hot water
burner pressure. In this mode the inlet gas supply pressure and CO/CO
Refer to Technical Data, Section 2.1 and 2.2 for the required differential burner pressure values.
Note: The burner pressure settings have been factory set and should not require adjusting.
Outlet
pressure
test point
Min. CO
2
adjustment
(under cap)
Inlet
pressure
test point
Fig. 26
5.7 FINAL COMMISSIONING
1. Allow the heating system to heat up, then balance the system to achieve the necessary temperature difference across
the heating flow and return pipes at the boiler and check the system volume and pressure. (Refer to Technical Data,
Sections 2.1, 2.2 and 2.3).
2. Seasonality valve (C models only) - The valve can be adjusted to the User's requirements, i.e. to the required
temperature of hot water from the tap. This is achieved by fully opening a hot water tap and turning the adjusting screw
(refer to Fig. 13a) with a screwdriver. Anticlockwise to increase the temperature and clockwise to decrease.
3. Turn off the boiler.
4. Thoroughly flush out the water pipework (refer to Section 3.9) and with no pressure in the boiler heating circuit, empty the
cyclone (if applicable) at it's drain point (see Fig. 13) of any debris. Clean the mains water inlet filter (see Fig. 13).
5. Re-pressurise the system as described in Section 5.1.
Max. CO
2
adjustment
+
ratio can be checked.
2
-
P2 P1
-
+
Fig. 27
Alpha InTec C and X - Commissioning
25