17
IMPORTANT
It’s imperative that a sufficient dynamic – gas –
pressure is maintained at all times. Should the
dynamic gas pressure fall below an acceptable
level, the appliance may malfunction or sustain
damage.
5.8
FINAL FLUSHING OF THE HEATING SYSTEM
The system shall be flushed in accordance with
BS 7593 (I.S. 813 ROI). Should a cleanser be
used, it must be suitable for Aluminium heat
exchangers. It shall be from a reputable
manufacturer and shall be administered in strict
accordance with the manufacturers’ instructions
and the DWTA code of practice.
5.8.1
INHIBITORS
See Section 3 “General Requirements”.
5.9
SETTING THE FLOW OUTLET TEMPERATURE
The flow outlet temperature can be adjusted
between 40 °C - 80 °C for standard CH system and
between 20 °C - 45 °C for under-floor systems by
using the Heating thermostat knob (see fig.1).
5.9.1
SETTING THE DHW OUTLET TEMPERATURE
The DHW outlet temperature can be adjusted
between 35 °C - 60 °C via the DHW thermostat
knob (see fig.1).
5.10
SETTING THE SYSTEM DESIGN PRESSURE
The design pressure should be a minimum of 0.5
BAR and a maximum of 1.5 BAR. The actual
reading should ideally be 1 BAR plus the equivalent
height in metres (0.1 BAR = 1 metre) to the highest
point in the system above the base of the appliance
(up to the maximum of 1.5 BAR total). N.B. The
safety valve is set to lift at 3 BAR/30 metres/45
psig. To lower the system pressure to the required
value, drain off some water from the appliance
drain valve until the required figure registers on the
pressure gauge (see fig. 1).
5.11
REGULATING THE CENTRAL HEATING
SYSTEM
Fully open all radiator and circuit valves and run
the appliance for both heating and hot water until
heated water is circulating. If conditions are warm
remove any thermostatic heads. Adjust radiator
return valves and any branch circuit return valves
until the individual return temperatures are correct
and are approximately equal.
5.11.1 REGULATING THE DHW FLOW-RATE
The appliance is fitted with a flow rate restrictor
that limits the maximum flow rate that can be drawn
through the appliance.
The restrictor eliminates the need to manually
adjust the DHW flow rate. However if it is felt
necessary to further increase or decrease the
available flow rate, spare restrictors are included
in the accessory pack.
The spare flow rate restrictors can be fitted to
either increase or decrease the maximum flow
rate. The tables overleaf denote the size of restrictor
fitted and the spare restrictors supplied in the
accessory pack. Each restrictor is colour-coded
to enable identification.
5.11.2 CHANGING THE FLOW-RATE RESTRICTOR
Refer to 6.27 for detailed instruction on changing
the flow restrictor.
Unica 28HE
9-litres
10-litres 11-litres
(Orange)
(Blue)
(Beige)
Spare Fitted
Spare
Unica 32HE
11-litres
12-litres 13-litres
(Beige)
(Red)
(Olive)
Spare Fitted
Spare
Unica 36HE
13-litres
14-litres 15-litres
(Olive)
Spare Fitted
spare
5.12
FINAL CHECKS
•
ENSURE ALL TEST NIPPLES ON THE
APPLIANCE GAS VALVE ARE TIGHT AND
CHECKED FOR SOUNDNESS.
•
ENSURE THE APPLIANCE FLUE
SYSTEM IS FITTED CORRECTLY AND IS
PROPERLY SECURED.
•
ENSURE ALL PIPE WORK IS RE-
CHECKED FOR SOUNDNESS.
•
RE-FIT APPLIANCE CASING.
•
COMPLETE BENCHMARK CHECKLIST.
FOR UK ONLY
Complete details of the boiler, controls, installation
and commissioning in the Benchmark checklist
at the back of this book. It is important that the
Benchmark checklist is correctly completed and
handed to the user. Failure to install and
commission the appliance to the manufacturers
instructions may invalidate the warranty.
5.13
INSTRUCTING THE USER
Hand over all documentation supplied with this
appliance – including these instructions – and
explain the importance of keeping them in a safe
place.
Explain to the user how to isolate the appliance
from the gas, water and electricity supplies, and
the locations of all drain points. Show the user how
to operate the appliance and any associated
controls correctly.
Show the user the location of the filling valve and
how to top-up the system pressure correctly and
show the location of all manual air release points.
Explain to the user how to turn off the appliance
for both long and short periods and advise on the
necessary precautions to prevent frost damage.
Explain to the user that for continued safe and
efficient operation, the appliance must be serviced
annually by a competent person.
IMPORTANT
To validate the appliance warranty, it’s necessary
to register the appliance details with us. The
warranty can be registered in several ways:
•
By completing the warranty registration
card and posting to us using the envelope supplied
•
Online at: vokera.co.uk
•
For UK residents by calling: 0870 607
0281
•
For ROI residents by calling: 1850
221121.
