Supplied By www.heating spares.co Tel. 0161 620 6677
22
7.1
CHECKING APPLIANCE OPERATION
When carrying out any repairs or servicing to the
appliance, the relevant commissioning procedure must
be undertaken to ensure the continued safe operation
of the appliance. Particular attention should be made
to ensure gas soundness, water soundness, and the
electrical integrity of the appliance.
7.2
APPLIANCE MODES OF OPERATION
NOTE
There must be sufficient system water pressure
(min. 0.5 bar) to ensure the water pressure switch
is activated. If there is insufficient system pressure
the pump and fan will be prevented from operating
and the low-pressure fault code will be displayed.
The 2-digit display can show several different
modes of operation:
OFF mode
Frost protection mode active
Combustion analysis mode active
Autostop function active
Normal heating request (example 60
o
C).
7.2.1
SELECTOR SWITCH IN THE OFF/STANDBY
POSITION
When the selector switch is in the OFF/STANDBY
position, the following functions are active.
Active functions:
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Frost-protection system
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Pump anti-block
7.2.1
ON-BOARD FUNCTIONS
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THERMOREGULATION: when an external
sensor is connected to the appliance, the
electronic circuitry will automatically adjust the
flow outlet temperature to suit local weather
conditions in order to maintain comfort and
efficiency. A specific operating curve that is most
suited to the system type and geographical area
can also be selected.
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OPE: OT+ is a communication
protocol that enables the boiler to be linked or
connected to other OT+ controls. These controls
have been designed to further increase fuel
economy by ensuring the boiler remains in the
modulation phase during any heating requests.
This reduces the amount of ON/OFF periods
and therefore increases fuel efficiency.
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AUTOSTOP: further information on the AUTO-
STOP function, can be obtained from your local
Vokera Sales Representative.
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CO FUNCTION: the CO function when
activated, will allow the appliance to run at
maximum and minimum output whilst a
combustion analysis check is being carried out.
Whilst the CO function is active, all other
functions are disabled (minimum power
operating period, anti-cycle, set-point, etc).
Once enabled, the CO function will remain active
for a 15-minute period, or until the function is
manually deactivated
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FROST-PROTECTION: this function is only active
when there are no requests for heating or HW. If
the temperature drops below 6°C, the boiler will
operate on minimum power until the temperature
of the primary thermistor reaches 35°C. Thereafter
the pump & fan will over-run for 30-seconds.
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ANTI-CYCLE FUNCTION: the anti-cycle
function ensures the burner remains switched
off for at least 3-minutes after the set-point
hysterisis (set-point + 5-deg).
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PUMP ANTI-BLOCK FUNCTION: when there
has been no heating or HW request for 24-hours,
the anti-block cycle is activated. The pump will
be activated for a period of 30-seconds.
6.20
FLUE COLLECTOR REMOVAL (fig. 31)
Carry out component removal procedure as
described in 6.4. Unclip and remove the air
chamber front and left side covers. Locate and
remove the screw (A) that secures the flue gas
analysis test point cover (B). Gently pull down
and to the left and ease the flue collector from its
location. Replace in the reverse order.
B
A
Fig. 31
SECTION 7 CHECKS, ADJUSTMENTS AND FAULT FINDING