Alpha Alpha 500E User manual

User's
Instructions
For use with Natural Gas only
Leave these instructions with the User
Wall Mounted, Fan Assisted, Room Sealed, Gas Fired
Combination Boiler with Unvented Hot Water Storage
Alpha 500E
Alpha 500E G.C. No. 47 532 07
Service Listed
0051
Building Regulations
Certificate No. ETC 00795
Nepicar House, London Road,
Wrotham Heath, Sevenoaks,
Kent TN15 7RS
For Technical help or for Service call ...
ALPHA HELPLINE
Tel: [phone]

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1 DESCRIPTION
The Alpha 500E boiler is a wall mounted, fan assisted room-sealed combination boiler incorporating an unvented hot water
storage cylinder. It provides both central heating and domestic hot water at mains pressure.
As supplied, the boiler is suitable for central heating systems requiring between 10.4 and 28.0 kW (35 500 and 95 550 Btu/h).
It 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.
2 USER CONTROLS
3 BOILER CONTROLS
1. CENTRAL HEATING THERMOSTAT
This thermostat controls the temperature of the water leaving the boiler for the heating system. For maximum output from the
radiators the thermostat should be left at maximum. If lower heating temperatures are required, turn the thermostat anti-clockwise.
2. DOMESTIC HOT WATER THERMOSTAT
This thermostat controls the temperature of the domestic hot water leaving the boiler. For maximum hot water temperatures the
thermostat should be left at maximum. If lower temperatures are required, turn the thermostat anti-clockwise.
3. SELECTOR SWITCH
This control allows the boiler to provide central heating and hot water or hot water only. The '0' position will turn the boiler off.
4. PRESSURE GAUGE
This indicates the central heating system pressure. It should always be within the green band when cold, increasing slightly
when hot.
If the pressure falls below the green band, ie red area, the system needs re-pressurising. Contact your Installer to have the
system checked and pressurised.
Alpha 500E
Fig. 1
Clock
(if fitted)
System
Pressure
Gauge
Central
Heating
Thermostat
Domestic
Hot Water
Thermostat
Selector
Switch
Burner
Viewing
Window
0THERMOSTAT 0THERMOSTAT 0SELECTOR
bar
04
3
2
1
Indicator
Neons
Red
Reset
Button
White
Reset
Button
RESET
RESET

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5. INDICATOR NEONS
When illuminated, the following conditions apply:-
Warning light (continuously on) - blocked flue or fan fault, contact your Service Engineer.
Overheat thermostat has operated - press white reset button (see Fig. 1) to reset.
Electrical supply to the boiler is on.
Boiler is supplying hot water.
Boiler is supplying central heating.
When the red reset button ( ) is illuminated it indicates that the burner has failed to light - Press the red reset button
(see Fig. 1) and the ignition sequence will restart.
6. OVERHEAT THERMOSTAT
This thermostat automatically switches the boiler off in the unlikely event of the boiler overheating. When the thermostat
operates, the neon is illuminated. Press the white reset button (see Fig. 1) and the ignition sequence will restart.
If this continually happens, contact your Service Engineer.
7. PRESSURE RELIEF VALVES
If the central heating or hot water system overheats and steam or water is discharged from the pipe connected to the valve or from
the tundish, turn the boiler off and contact your Service Engineer. Your Installer should have told you where these pipes terminate.
8. FROST THERMOSTAT
The boiler has a built-in frost thermostat, which automatically operates the boiler if the water temperature falls below 5°C,
providing the electrical supply neon is illuminated.
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 (flats on the spindle in line with the valves).
d. The gas and water supplies are on at the mains.
e. The heating system pressure is within the green band as shown on the pressure gauge.
2. Turn the heating and hot water thermostats fully anticlockwise to 0 and set the selector switch to 0.
3. Switch on the electrical supply to the boiler.
4. Set any room thermostats to maximum and ensure that any clock is in an 'on' position. Refer to section 8, if a clock is fitted
in the boiler control panel.
5. Set the selector switch to (hot water only). The neon will illuminate, indicating the electrical supply to the boiler is on.
6. Turn the hot water thermostat fully clockwise. The main burner will light and the hot water storage cylinder will be heated.
After approximately 12 minutes (from cold) the boiler will be ready to provide hot water and the burner will go out.
7. Set the selector switch to (central heating and hot water) and turn the heating thermostat fully clockwise. The main
burner will light and the boiler will provide central heating.
8. Set the boiler and all other controls, ie room thermostat etc, to the desired positions.
To turn the central heating off i.e. in Summer:- Set the selector switch to (hot water only).
To turn the boiler off for short periods:- Set the selector switch to (hot water only).
Note: In this position the pump will automatically operate for 5 minutes in every 24 hours. If the water temperature falls below
5°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:- Set the selector switch to 0. 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.
Alpha 500E

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5 BOILER OPERATION
The operating sequence of the boiler is controlled by the selector switch on the control panel. With the switch 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.
Setting the selector switch to (central heating and hot water) the boiler will operate to provide both central heating and
hot water.
If the boiler is operating to provide central heating and a hot water tap is opened, the boiler will give priority to provide hot water.
Such an interruption in the central heating should not 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 boiler is set to provide both central heating and hot water, it will respond to a demand for heat in the following sequence:-
The pump will start, the fan will start and the main burner will light.
The output of the burner is automatically controlled to suit the system demand.
When the temperature of the heating 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. The pump will continue to run for 3 minutes to remove any residual
heat from the boiler.
When a hot tap is opened, hot water is provided instantly. When the temperature of the water in the storage cylinder falls to
below that set by the thermostat, the pump will start, the fan will start and the main burner will light to reheat the water in the
storage cylinder.
Thesupplyofhotwaterisinstantaneousattheboiler,butthetimetakentoreachatapwilldependonthelengthofthepipebetween
the tap and the boiler.
The flow of water to the hot taps will depend on the mains water pressure.
6 IMPORTANT NOTES
1. BOILER LOCATION
Always ensure the following clearances are available around the boiler:-
Top: 200 mm, Bottom: 250 mm, L/H side: 20 mm, R/H side: 5 mm, Front: 450 mm
If the boiler is installed in a cupboard or compartment, ensure that all ventilation openings are clear. Do not store any other articles
in the cupboard containing the boiler and never place any clothing or combustible material on or near the boiler or flue pipe.
2. FLUE TERMINAL
The terminal on the outside wall must not be allowed to be obstructed. If it is damaged, in any way, turn the boiler off and
contact your Service Engineer.
In cold weather, steam may be emitted from the terminal. This is quite normal.
3. MAINS FAILURE
In the event of an electrical supply failure the boiler will not operate. When the supply is restored, the boiler will return to normal
operation. Remember to reset the clock when the supply is restored.
If the mains water supply fails, there will be no hot water from the taps. The boiler will continue to provide central heating.
4. ADDITIONAL BATHROOM FITTINGS
Any equipment such as mixing valves, showers, bidets etc. must be designed to operate at mains water pressure. Contact your
local Water Authority for advice when considering purchasing such items.
5. CLEANING
Use only a damp cloth and mild detergent to clean the boiler outer casing. Do not use abrasive cleaners.
6. SERVICING
To maintain efficient and safe operation of your boiler, routine annual servicing is essential.
For advice on servicing contact:-
The Alpha Helpline: 01322 669443 or your local Gas Region.
Alpha 500E

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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 is used or a 5 A fuse if any other type of plug is used.
To connect a plug:-
The colour of the wires in the mains lead of the boiler may not correspond with the coloured markings identifying the terminals
in your plug. In this case proceed as follows:-
The wire coloured green and yellow must be connected to the terminal in the plug that is marked with the letter E, or by the
earth symbol , or coloured green or green and yellow.
The blue wire must be connected to the terminal which is marked with either the letter Nor coloured black.
The brown wire must be connected to the terminal which is marked with the letter Lor coloured red.
THE APPLIANCE MUST BE EARTHED.
7 GAS SAFETY REGULATIONS
Gas Safety (Installation and Use) Regulations 1984 (as amended):-
It is the law that all gas appliances are installed and serviced by a competent person, ie CORGI registered personnel. Failure to
install or service appliances correctly could lead to prosecution. It is in your interest and that of safety to ensure compliance
with the law. The manufacturer's instructions must not be taken in any way as over-riding statutory obligations.
The Benchmark Log Book must be fully completed by the installer on installation of the boiler. All CORGI registered installers
carry a CORGI ID card and have a registration number. Both should be recorded in your central heating Log Book. You can
check your installer is CORGI registered by calling CORGI on 01256 372300.
8 CLOCK (if fitted)
The clock allows you to set the times at which the boiler will operate to provide central heating. It does not affect the supply
of domestic hot water, which is always available.
1. TO SET THE TIME
Turn the outer dial clockwise to set the clock hands to
the correct time.
(Ensure the time indicator corresponds with the correct
time on the 24hr dial as shown in Fig. 2,
e.g. 3.00pm = 15 not 3).
NOTE: Do not rotate the dial anti-clockwise
2. TO SET THE ON/OFF PERIODS
Select the ON times by pushing the tappets to the
outside.
Select the OFF times by pushing the tappets to the
inside.
Fig. 2 shows the clock set as follows:-
ON 3.00pm to 10.00pm (15 - 22)
OFF 10.00pm to 5.00am (22 - 5)
ON 5.00am to 8.00am (5 - 8)
OFF 8.00am to 3.00pm (8 - 15)
3. MANUAL SWITCH
The clock has a manual On/Off switch which operates as follows:-
Mid position Heating On/Off as set by the tappets
Position I(right) Heating On continuously
Position 0 (left) Heating Off continuously
Alpha 500E
Fig. 2