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Alpha HE25 and HE33

The operating sequence of the boiler is controlled by the selector switch on the control panel. When the selector switch is set to 
(hot water only) the boiler will only operate to provide domestic hot water, ideal for Summer use when central heating is not required.

With the selector switch set to position (2) the boiler will operate to provide central heating and for the hot water as well.

If the boiler is operating to provide central heating and a hot water tap is opened, the boiler will automatically switch over to provide
hot water. Such an interruption in the central heating should not generally be noticed by any reduction in room temperature.

Note: If a clock is fitted to the boiler, it will only control the operating times of the central heating. Hot water will always be
available when a tap is opened.

When the selector is set to position (2), it will respond to a demand for heat in the following sequence:-
a. The pump will start, the fan will operate at full speed and the main burner will light.
b. The output of the burner is automatically controlled to suit the system demand.
c. When the temperature of the system water in the boiler reaches that set by the thermostat or the room thermostat is

satisfied, the main burner is turned off and the fan stops after 20 seconds. The pump will continue to run to remove any
residual heat from the boiler.

d. When a hot tap is opened, the boiler automatically senses a flow of water. The pump will start, the fan will operate at full

speed and the main burner will light.

e. The boiler will continue to supply hot water at the temperature set by the thermostat until the tap is closed.

5

BOILER OPERATION

6

HOT WATER USE

4

LIGHTING INSTRUCTIONS

Refer to Fig. 1 for boiler controls.

1.

Ensure the following:-
a. Electrical supply to the boiler is off.
b. All heating controls and thermostats are set to OFF or minimum position.

c. All isolation valves at the bottom of the boiler are in the open position (slot on the spindle in line with the valves i.e.   ).

d. The gas and water supplies are on at the mains.
e. The heating system pressure is within the green band as shown by the pressure gauge.

2.

Switch on the electrical supply to the boiler.

3.

Set any room thermostats to maximum and ensure that any clock is in an 'on' position.

4.

Set the selector switch to 

 (hot water only).

5.

Turn the hot water thermostat fully clockwise. Open a hot water tap, the main burner will light and the boiler will provide hot
water. Close the tap and the burner will go out.

6.

Set the selector switch to position (2) and turn the heating thermostat fully clockwise, refer to Section 3.1. The main burner
will light and the boiler will provide central heating.

7.

Set the boiler thermostats, clock, external controls i.e. room thermostat to your chosen settings and the boiler is ready to operate.

To turn the central heating off i.e. in Summer:- Set the selector switch to position (1).

To turn the boiler off for short periods:- Set the selector switch to position (1).
Note: In this position the pump will automatically operate for 5 minutes in every 24 hours. If the water temperature falls below
8°C the built-in frost thermostat will operate the boiler automatically until the temperature of the water in the heating system has
been raised.

To turn the boiler off for longer periods:- Switch off the electrical supply to the boiler. If required, all supplies i.e. gas, water
and electricity may be turned off at the mains. If there is any possibility of the boiler being left during frost conditions, then the
boiler and system should be drained and a label attached to the boiler drawing attention that the system has been drained. If
this is required, contact your Service Engineer.

The supply of hot water is almost instantaneous at the boiler, but the time taken to reach a tap and the temperature at which it leaves
the tap will depend on the rate at which the water is drawn off and the length of the pipe between the tap and the boiler.

Fully opening a hot tap may not always provide the maximum temperature as the flow rate may be too high, try closing it slightly until
the maximum temperature is achieved.

Depending on your mains water pressure, it may not be possible to operate several hot taps at the same time.

Summary of Contents for Alpha HE25

Page 1: ...e For use with Natural Gas only Leave these instructions with the User Alpha HE25 and HE33 Nepicar House London Road Wrotham Heath Sevenoaks Kent TN15 7RS For Technical help or for Service call ALPHAHELPLINE Tel 0870 3001964 Alpha HE25 G C No 47 532 41 Alpha HE33 G C No 47 532 43 British Gas Service Listed ...

Page 2: ...rs will provide central heating as required during the on times set on your clock if fitted Hot water is always available whenever a hot tap is opened and takes priority over the central heating The burner is lit electronically and the heat output is controlled by a modulating gas valve Pull the controls panel cover forward and down to gain access to the controls 2 USER CONTROLS 1 DESCRIPTION Fig ...

Page 3: ...ery slowly every 5 seconds Electricity supply to the boiler is on B Illuminated continuously Burner is alight B Flashing on and off Temperature sensor fault contact your Service Engineer A Flashing on and off Overheat or flue thermostat has operated Rotate selector switch to the reset position 3 to reset If this continues to happen contact your Service Engineer A Illuminated continuously Burner ha...

Page 4: ...The gas and water supplies are on at the mains e The heating system pressure is within the green band as shown by the pressure gauge 2 Switch on the electrical supply to the boiler 3 Set any room thermostats to maximum and ensure that any clock is in an on position 4 Set the selector switch to hot water only 5 Turn the hot water thermostat fully clockwise Open a hot water tap the main burner will ...

Page 5: ...er routine annual servicing is essential For advice on servicing contact The Alpha Helpline 0870 3001964 7 GAS LEAK If a fault or gas leak is suspected turn off the gas supply Do not touch any electrical switches do not smoke and extinguish all naked flames Contact your local Gas Region immediately 8 ELECTRICAL SUPPLY The boiler requires a 230 240 V 50 Hz supply fused at 3 A if a 13 A 3 pin plug i...

Page 6: ...ber Both should be recorded in the Checklist You can check your installer is CORGI registered by calling CORGI on 01256 372300 A B C D E Where applicable refer to the label on the inside of the hinged cover for guidance on repressurising the system Or contact your installer Or Check that the electrical supply to the boiler is on If so Check that all controls are calling for heat i e room thermosta...

Page 7: ...7 Alpha HE25 and HE33 ...

Page 8: ... instructions have been carefully prepared but we reserve the right to alter the specification at any time in the interest of product improvement Alpha Therm Limited 2007 Alpha Therm Limited NepicarHouse LondonRoad WrothamHeath Sevenoaks Kent TN15 7RS Tel 0870 3001964 email info alphatherm co uk website www alpha boilers com ...

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