Checking The Expansion Vessel; External Faults - Riello Vokera VISION PLUS 20 S User Instructions

ƒ activate the combustion control function by pressing
buttons 2+3 for at least 2sec
+
ƒ the display shows the scrolling text CO and the icons Fig. 39
, and come on:
ƒ using the , keys it is possible to change the fan
speed
ƒ set the max value (rpm) and confirm the choise with
The display shows for 10 sec. the number of revs set, together
with the rpm icon.
ƒ The boiler will function at max power.
ƒ Check on the analyser that the max CO
what indicated in the table, if data are different proceed
with the calibration of the gas valve - see paragraph ""8.11
Gas valve calibration"" .
NATURAL GAS
CO max
2
20 S
25 S
30 S
ƒ Set the min value (rpm) and confirm the choise with
ƒ The display shows for 10 sec. the number of revs set,
together with the rpm icon.
ƒ The boiler will function at min power.
ƒ Check on the analyser that the min CO2 complies with
what indicated in the table, if data are different proceed
with the calibration of the gas valve - see paragraph ""8.11
Gas valve calibration"" .
NATURAL GAS
CO min
2
(G20)
20 S 9,0
25 S 9,0
30 S 9,0
ƒ by pressing button it is possible to stop function in
advance
When the checks are completed:
ƒ exit the function by pressing the button
ƒ remove the analyzer probe and close the combustion
analysis sockets with the appropriate plugs and relative
+
RESET MENU
2 3
complies with
2
LPG
(G20) (G31)
9,1 10,0
9,0 10,0
9,1 10,0
LPG
(G31)
10,0
10,0
10,0
screw
ƒ replace and store the analysis probe adapter supplied with
the boiler, in the documentation envelope
ƒ set the boiler in the desired operating mode according to
the season
ƒ adjust the required temperature values according to custo-
mer requirements.
b
When the combustion analysis is in progress all heat
requests are inhibited and a message is shown on the
display.
IMPORTANT
The combustion analysis function is active for a maximum time
of 15 minutes; the burner shuts down if an outlet temperature
of 95° C is reached. It will ignite again when the temperature
, falls below 75° C.
b
With OTBus device connected it is not possible to
activate the combustion control function. To perform flue
gas analysis, disconnect the OTBus connection wires
and wait 4 minutes, or disconnect the power supply and
re-power the boiler.
b
The combustion analysis function is normally performed
with the three-way valve positioned in heating mode.
8.5

CHECKING THE EXPANSION VESSEL

Carry out the component removal procedure as described in
7.9. You must ensure that the boiler is completely drained of
water. Using a suitable pressure gauge, remove dust cap on
.
expansion vessel and check the charge pressure. The correct
charge pressure should be 1.0 bar ± 0.1 bar. If the charge
pressure is less, use a suitable pump to increase the charge.
NOTE
You must ensure the drain valve is in the open position whilst
re-charging takes place. Replace the dust cap and carry out
the relevant commissioning procedure (section 6).
8.6

EXTERNAL FAULTS

Before carrying out any faultfinding or component replacement,
ensure the fault is not attributable to any aspect of the installation.
8.6.1 INSTALLATION FAULTS
Symptom
No ignition
No hot water
% No heating
%
% Fault
Fault code
.
%
%
%
Possible cause
Check wiring/check electrical
supply
Check external controls
Check external controls
Possible cause
Check gas supply, check flue
system, check polarity
37