VOKERA Hydra Installation & Servicing Instructions Manual - page 19
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however the remaining parameters (5 – 42) can
only be accessed after entering the relevant
service code, and should only be adjusted by
qualified service personnel.
5.10
PARAMETERS 1 - 4
Parameters 1 - 4, are used to alter or adjust the
settings for central heating and domestic hot
water. Use the following table and procedure to
check or adjust the relevant parameters:
●
Press the
mode
button until “PARA” appears
in the display.
●
Press the
S
button until the appropriate
parameter is shown in the left side of the
display.
●
Use the
+
or
-
buttons to adjust the value
of the paramater as shown in the right side of
the display.
●
Press the
M
button to store the new setting.
●
Press the
reset
button to return to the
stand-by mode.
IMPORTANT
Under no circumstances should any parameters
- other than those shown above - be changed or
adjusted by non competent personnel.
5.11
INFORMATION MODE
The appliance keypad can be used to display
certain information on the working status of the
boiler. Information such as flow & return
temperature, and temperature rise can be viewed
using the following table and procedure:
●
Press the
mode
button until “INFO” appears
in the display.
●
Press the
S
button until the appropriate step
number is shown in the left side of the display.
●
The measured value of each step is shown on
the right side of the display.
●
Press the
mode
button until “Stby” appears
in the display to return to the stand-by mode.
5.12
SETTING THE SYSTEM DESIGN PRESSURE
The design pressure should be a minimum of 1
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, pull lever on head of safety valve to release
water until the required figure registers on the
pressure gauge (fig. 1).
5.13
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.
5.14
CHECKING DYNAMIC GAS PRESSURE
Isolate the appliance from the electrical supply
and remove the appliance casing as described in
section 4.10. Unclip and remove the front air
chamber cover.
Attach a suitable manometer to the inlet test
nipple of the gas valve.
Restore the electrical supply to the boiler and
generate a request for central heating via the
room thermostat and/or timer.
Press the
mode
and
+
buttons at the same
time, the boiler will now run at full power for 15
minutes.
The dynamic gas pressure will now be shown on
the manometer, and should be 20 mbar +/- 1 mbar.
If the dynamic gas pressure is out-with the
tolerance range, you should contact the gas
supplier for advice.
Press the
+
and
-
buttons at the same
time to return to the normal operating mode.
Isolate the appliance from the electrical supply,
remove the manometer from the inlet test nipple,
tighten the test nipple screw, and check for
soundness.
Refit the air chamber cover and appliance casing
in the reverse order.
Parameter
Description
Range
1
2
3
4
Hot water outlet temperature
Hot water mode
Heating mode
Heating outlet temperature
40
°
C - 65
°
C
00 = off
01 = on
02 = N/A
03 = N/A
00 = off
01 = on
03 = off
(pump on continuously)
04 = on
(pump on continuously)
20
°
C - 90
°
C
Step number
Information displayed
1
Temperature at flow sensor
2
Temperature at return sensor
3
Temperature at cold water inlet sensor
4
Temperature at external sensor (if present)
5
Unused
6
Required temperature (as set at parameter 1 or 4)
7
Temperature rise of flow sensor (measured in
°
C
per second)
8
Temperature rise of return sensor (measured in
°
C per second)
9
Temperature rise of hot water (measured in
°
C
per second)
A
Unused