Operation; General - Heatrae Sadia HI-MAX INSTANT ID 5-60 Installation, Operation And Maintenance Manual

8. Operation

8.1 General


Please note that this product has been
designed to make the operation of the unit and its
subsequent generation of heating and hot water
as simple for the end user as possible. The factory
settings that the HIU is delivered with are suitable
for most systems.
As the unit is designed to be installed on a sealed
heating system, from time to time the system will
lose pressure and need to be topped up using the
fi lling loop inside the HIU. This can be done by
following a simple procedure laid out later in this
section of the instructions.
DANGER
Disconnect the
opening the cover.
8.1.1 Benchmark
The heat interface unit is covered by the Benchmark
Scheme, which aims to improve the standards of
installation and commissioning of domestic heating
and hot water systems in the UK and to encourage
regular servicing to optimise safety, effi ciency and
performance.
Benchmark is managed and promoted by the Heating
and Hot water Industry Council. For more information
visit www.centralheating.co.uk.
Please ensure that the installer has fully completed
the Benchmark Checklists on pages 52 to 53 of this
manual and that you have signed it to say that you have
received a full and clear explanation of its operation.
This product should be serviced regularly to optimise
its safety, effi ciency and performance. The service
engineer should complete the relevant Service Record
on the Benchmark Checklist after each service. The unit
must be serviced annually by a competent engineer to
maintain the warranty.
The Benchmark Checklist may be required in the event
of any warranty work.
8.1.2 Domestic hot water fl ow performance
When initially opening hot outlets a small surge in
fl ow may be noticed as pressures stabilise. This is
quite normal with unvented systems. In some areas
cloudiness may be noticed in the hot water. This is due
to aeration of the water, is quite normal and will quickly
clear.
8.1.3 DHW temperature controls
The hot water temperature is controlled by a PID
controller within the Heatrae Sadia HI-MAX INSTANT
HIU. A factory set Stv acts as a high temperature
protection device in the event of a component failure
or controls malfunction.
Once the PID controller is set there is no need to reset
the hot water temperature set point in the HIU.
electrical supply before
8.1.4 Heating temperature controls
The heating system fl ow temperature supplied from
the HIU is controlled by the PID controller within
the Heatrae Sadia HI-MAX INSTANT HIU. Once the
PID controller is set there is no need to adjust this
temperature.
The room temperature and the demand for heat from
the HIU is controlled by the programmable room
thermostat on a radiator system or the underfl oor
heating controller on an underfl oor heating system.

For details on the space heating system
controls refer to the separate controls instructions.
CAUTION
The heating system is set up by the installer
to suit the conditions and limitations of the
installation. It is imperitive that these settings
are not adjusted by the end user, as this could
result in damage to the system or property.
8.1.5 Operational faults and errors
Operational faults and their possible causes are
detailed in the Fault Finding section on pages 40 to
43 of this book. It is recommended that faults should
be checked by a competent installer. These can be
identifi ed with a code beginning with an "F".
Operational errors occur from time to time and are
perfectly normal. As mentioned earlier, one such error
is that of a heating system low pressure condition as
indicated in Figure 48 below.
Figure 48: Low pressure fault condition
If the heating system pressure drops below the minimum
setting (approx 0.7 bar g) the controller will prevent the
heating pump from operating. This is to prevent any
damage to the pump, in this case the heating system will
need to be topped up by following the system top up
procedure.
Figure 49: Error or fault with the heating system
C
If there is an issue (either a fault and/or an error) with the
heating system, the hot water system is still allowed to
operate. In which case you will see the screen as detailed
in Figure 49 or the two dashes for the standby mode
display. Simply press the OK button to scroll through the
faults / errors. The number below the fl ashing triangle
indicates the number of faults / errors logged.
O
O
35