
Installation and Servicing
Instructions
Alpha CombiMax
2kW Immersion Heater Kit
Suitable for use with the
CombiMax 350 and 600 Unvented Hot Water Store
Immersion heater kit - Part No. 1000462
For Technical help or for Service call ...
ALPHA HELPLINE
Tel: 0870 3001 964
Nepicar House, London Road,
Wrotham Heath, Sevenoaks,
Kent TN15 7RS
These instructions must be used in conjunction with the Installation instructions provided
with the selected combination boiler and CombiMax.
Leave these instructions with the User

1 INTRODUCTION
The Alpha Immersion Heater is for use with the Alpha CombiMax 350 and 600 unvented secondary hot water storage cylinder
and must be obtained from Alpha Therm Ltd. (Immersion heater kit Part No. 1000462). It's purpose is to deliver a limited
amount of hot water when the boiler is not working.
A 3 kW immersion heater MUST NOT be fitted.
The 2 kW heater consists of a 1¼" BSP threaded boss, with control and overheat thermostats. The control thermostat setting
has been factory set to 55°C and must not be adjusted.
Notes:1. It is only possible to fit this immersion heater to a CombiMax produced after February 1999, i.e. after Serial
No. A90600001.
2. A minimum clearance of 350 mm below the CombiMax is required for installation and servicing. A clearance
less than 350 mm will not allow the heater to be replaced.
2 ELECTRICAL SUPPLY
The Alpha immersion heater requires a 230/240 V ~ 50 Hz mains supply, fused at 10 A.
The immersion heater must be earthed.
The heater must be connected to an independent electrical supply, i.e. the supply used for the CombiMax, boiler and external
controls must not be used.
The heater should be connected to a 10 A fused double pole switch with a contact separation of at least 3 mm in both poles or
a 10 A fused 3-pin plug and unswitched socket outlet (both complying with BS1363). Ensure heat resisting flexible cable (i.e.
85°C) not less than 1.5 mm² complying with BS6141:Table 8 or Table 15, is used for connection to the heater.
All external wiring must be in accordance with the current IEE Wiring Regulations (BS7671).
3 INSTALLATION
Where possible the immersion heater should be fitted before installation of the CombiMax. If this has not been possible, then
drain the CombiMax store as described in section 8.2 of the CombiMax instructions.
To fit the heater a minimum clearance of 350 mm is required beneath the CombiMax.
Fit the heater as follows:-
1. Remove the blanking cap from the boss at the bottom of the CombiMax storage cylinder.
2. Ensure all sealing material is removed, and that there is no damage to the sealing face and thread of the boss.
3. Apply a small amount of grease to the 'O' ring seal and engage the heater into the boss and gently tighten using an
appropriate spanner.
4. Remove the nut securing the heater cover and remove the cover. Pass the electrical supply cable through the cable clamp
and connect as follows:-
Brown wire to L, Blue wire to N and Green/Yellow wire to .
Ensure correct polarity and that the cable is secured in the cable clamp as shown. See Fig. 1.
Note: Ensure that the length of the earth wire is such that if the supply cable is pulled out of the clamp, the live and neutral
wires become taut before the earth wire.
Alpha CombiMax Immersion Heater
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Fig. 1

5. Check that all screws/terminals have been tightened and replace the cover in reverse order.
Note: Do not adjust the thermostat as it has been factory set.
6. Carry out electrical system checks - short circuit, polarity, earth continuity and resistance to earth using a suitable multimeter.
Warning: DO NOT switch on the electrical supply to the heater until the storage cylinder is full of water.
4 USER INFORMATION
The User must be advised that the immersion heater has been fitted for emergency use only, in the rare situation where the
boiler/CombiMax has broken down. It must not be switched on unless the boiler cannot deliver hot water.
If the immersion heater is switched on, a limited supply of hot water will be supplied from the storage cylinder.
If the immersion heater is used when the CombiMax and boiler are operating correctly, it will not deliver extra hot water.
If the immersion heater is used when the boiler has failed, it will take approximately 1 hr for the CombiMax 350 and
approximately 1½ hr for the CombiMax 600 to heat the water in the store. This will provide approximately 30 litres of hot water
from the 350 model and approximately 50 litres of hot water from the 600 model.
5 SERVICING/REPLACEMENT OF PARTS
Before servicing or replacement of components is carried out on the boiler and CombiMax, ensure that the independent
electrical supplies to the immersion heater, boiler and CombiMax have all been isolated.
No regular servicing of the immersion heater is required.
A minimum clearance of 350 mm is required below the CombiMax to enable replacement of the heater or thermostat.
5.1 CONTROL/OVERHEAT THERMOSTAT
The immersion heater consists of a control and an overheat thermostat. If the control thermostat fails, the overheat thermostat
will operate at approximately 90°C, i.e. very hot water and stop the heater from working. If this occurs, the thermostat assembly
must be replaced as follows:-
1. Ensure all the electrical supplies to the heater, boiler and CombiMax are isolated.
2. Remove the nut securing the heater cover and remove the cover.
3. Disconnect the electrical connections and carefully lever out the thermostat from the housing.
4. Fit a new thermostat and re-assemble in reverse order.
5.2 IMMERSION HEATER
1. Drain the CombiMax as described in section 8.2 in the CombiMax instructions.
2. Remove the old heater and fit a new one as described in section 3 of these instructions.
Alpha CombiMax Immersion Heater
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Alpha Therm Limited.
Nepicar House, London Road, Wrotham Heath
Sevenoaks, Kent TN15 7RS
email: info@alphatherm.co.uk
website: www.alpha-innovation.co.uk
Manual compiled and designed by Publications 2000, Tel (01670) 356525
These 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 1999.
Part No. 0001122/2
09/99/D118