Heatrae Sadia ElectroMax User Instructions page 2

When the Programmable Room Thermostat
is in a heating period and the room
temperature is below that set it will switch
on the Electromax boiler to heat the
radiators and raise the room temperature.
2.3 Central & Underflooring Heating
The Electromax boiler works as part of
a "sealed" pressurized central heating
system. The unit is fitted with a pressure
gauge which will indicate the operating
pressure of the system. Within the unit all
necessary safety and functional controls
are factory fitted.
The boiler is fitted with a sophisticated
electronic control which will adjust the heat
input to the water circulated around the
radiators to maintain them at an optimum
temperature. Safety functions will shut the
boiler down in the unlikely event of a fault.
2.4 Hot water
The water heater fitted in the Electromax
is an unvented cylinder which gives the
benefit of high pressure water to all hot taps
and outlets connected to the unit. It requires
no cold water feed cistern, flow from the
hot outlets is governed by the mains water
pressure.
The bulk of the hot water will be heated
by cheaper "Off-Peak" electricity. This will
generally happen over night to give a full
tank of hot water for use during the day. If
the hot water store is fully used a "Boost"
element is provided to heat a smaller
quantity of water in a quicker time, typically
in less than an hour.
The water heating function operates
independently of the central heating boiler
so the boiler can be switched off during
summer months without affecting the hot
water performance.
2 User's Instructions
3.0 ELECTROMAX CONTROL
FUNCTIONS
Refer to Diagram 1 to help you identify
the various features and functions of the
Electromax controls panel.
3.1 Hot Water "On" switch
Switches on the electrical supply to the
water heater. When in the "on" position the
switch is illuminated. With the switch in the
"on" position the water heater will heat up
whenever an "Off-Peak" electrical supply
period is available.
3.2 Hot Water "Boost" switch and
indicator
Switches on the electrical supply to the
"Boost" element when pressed. NOTE: the
switch does not latch in the "on" position.
When the supply to the "Boost" element is
switched on the indicator will illuminate. The
"boost" is timed to operate for a maximum
of one hour, this is sufficient time to fully
reheat a smaller "boost" volume of water.
The "Boost" element cannot be switched on
if the Hot Water "On" switch is in the "off"
position.
3.3 Central Heating "On" switch
Switches on the electrical supply to the
boiler to provide central heating. When in
the "on" position the switch is illuminated.
With the switch in the "on" position the
operation of the boiler will be controlled by
the times set on the Programmable Room
Thermostat.
3.4 Boiler Status Display
DEMAND / OVERHEAT
When illuminated GREEN this indicator
indicates that there is a heating demand for
the central heating from the Programmable
Room Thermostat. It will flash for