Description Of The Product; General Description; Operation Principle - Heatrae Sadia R 45 PLUS 3KW Installation, Operation And Maintenance Manual

4. Description of the product

4.1 General description

These water heaters are a series of wall mounted units
that store and produce domestic hot water efficiently.
These vented units (unpressurized). mount securely
to the wall. Where required additional pressure safety
components may be added.
There are four models in the range:
R 25 PLUS
`
R 45 PLUS
`
R 70 PLUS
`
R 120 PLUS
`
The unit is supplied complete with safety and control
devices needed to allow connection to the cold water
supply where the pressure is below 10 bar. All these
components are preset and should not be tampered
with. The units' hot and cold pipes are situated so as
to provide ease of installation. The unit also has a
breather connection at the top that provides a visual
indication, via the tundish supplied, of overfilling should
1
16
15
14
13
11 10
12
Figure 4: Main components diagram
the unit fail. This must be vented to a suitable and safe
location, preferably an outside wall.

4.2 Operation principle

All the unit sizes produce DHW in the same way, by
heating the potable water volume via an immersion
heater. The hot water temperature programmed in the
unit is factory set to 60 degrees centigrade, but can
be adjusted to suit the installation requirements by
adjusting the temperature control at the bottom of the
unit under the access cover.
4.2.1 Temperature Control
The temperature of the stored water can be adjusted
between 38 degrees centigrade and 78 degrees
centigrade, this is achieved by adjusting the temperature
control at the bottom of the unit under the access cover,
see page 19.
4.2.2 Water inlet control
When hot water is drawn from the water heater, the unit
will detect a change in water level automatically and
request refill via a solenoid valve. The flow of potable
water is controlled via a flow restrictor, this ensures that
2
9
8 7
Number Part description
3
1
4
2
3 Level sensor assembly
4
5
5
6 Main electronic control
7
8 22mm hot outlet pipe
9 15mm water inlet (push fit elbow)
10
11
12
13 Power cable clamp assembly
14
15 Immersion heater
16
6
Table 4: Main components list
Product bracket
Breather gasket
Sensor cover
Tank assembly
Base cover
Potentiometer
Securing bracket
Drain valve
Inlet assembly
Wall bracket
9