Potterton Promax HE Store Installation & Servicing Instructions Manual page 32

Immersion Heater
Immersion Heater Wiring
Earth Post
EARTH
(Green/
Yellow)
Conductor
LIVE
(Brown)
Conductor
1.5mm 2 HOFR 3 Core Cable
(Must be routed and secured
via Cable Gland provided)
Fig. 14
32
Promax Store
RWC
Drain
Valve
Double
Check
Valve
Thermostat
Temperature
Adjustment
Dial
Thermal
Cut-out
Reset
Button
NEUTRAL (Blue)
Conductor
2.7 Immersion Heater
The immersion heater is rated 3kW at 240V and must be wired
to a separate, suitably rated electrical supply. THERE MUST
BE NO INTERCONNECTION WITH THE WIRING TO THE
BOILER.
WARNING: THE IMMERSION HEATER MUST BE
EARTHED.
It should be installed in accordance with the current IEE Wiring
Regulations and be wired through a double pole isolating
switch or suitable controller with a contact separation of at
least 3mm in both poles. The immersion heater must be fully
immersed and not switched on dry.
2.7.1 Wiring the immersion heater
The immersion heater must be wired with 85°C rubber
insulated HOFR sheathed flexible cable with a conductor cross
sectional area of 1.5mm
Table 8.
Remove the immersion heater cover by removing the securing
nut and pulling the cap away from the cylinder. The Live
(Brown) conductor should be connected directly to the
thermostat terminal marked A. The Neutral (Blue) conductor
should be connected directly to the thermostat terminal
marked B. The earth conductor should be connected to the
threaded post on the bracket marked
The supply cable outer sheath must be routed through the
cable gland supplied and secured by tightening the gland after
fitting. Ensure the connections to the immersion heater are not
under any strain before tightening.
Re-fit the protective cover over the immersion heater assembly
and secure by the nut previously removed tightened onto the
end of the threaded post where it emerges through the cover.
2.7.2 Operation
The immersion heater is controlled by the rod type thermostat
supplied. DO NOT USE ANY OTHER TYPE OF
THERMOSTAT.
A temperature setting of 60 to 65°C is recommended and is
factory preset (between position 4 and 5 on the adjustment
dial). This should be reduced to 55°C (position 3 on dial) in
hard water areas.
The thermostat incorporates a thermal cut-out which cuts the
power to the immersion heater in an overheat situation. Should
this operate it can be manually reset by pressing the red
button to the side of the temperature adjustment dial.
Note: Investigate the cause of over-heating and rectify before
resetting.
complying with BS6141
2
.
© Baxi Heating UK Ltd 2012