7
At any point during the start-up, running and shutting down of the burner, the burner operational mode is shown scrolling across the bottom of
the display screen. This can be one of several modes, depending on the operation of the boiler at the time it is viewed, as follows:
•
WAIT BOILER THERMOSTAT: boiler is in standby mode awaiting either a signal from the heating system controls and/or for the burner ON/
STANDBY switch to be set to ON to start the boiler, OR the temperature to fall to the Restart Temperature (5°C below the set temperature)
•
WAIT PRELOAD BRAZIER: initial loading of pellets into the burner brazier to enable the burner to be lit.
•
WAIT LIGHTING: period of time taken for the pellets to light, for the flame to stabilise and then for small amounts of pellets to be added to
build up the flame in the brazier.
•
PELLET BURNER FIRING – Power 100%: flame is fully developed and boiler is operating on full power.
•
PELLET BURNER FIRING – Power 99% - 25%: boiler output is being modulated down.
•
PELLET BURNER FIRING – Power 25%: boiler is operating at minimum output.
•
TURNING OFF BRAZIER: burn-down period to remove any pellets remaining in the brazier.
•
WAIT POST PURGE: period of time after burn-down is complete to ensure no unburnt pellets ignite.
5.2 Error Messages
The burner control panel display can also indicate that a fault has occurred with the boiler. In the event of a fault, one of the following error (fault)
messages may be seen scrolling across the bottom of the display screen:
•
FAILED PELLET LIGHTING
•
SERVO MOTOR BLOCKED
•
PROBE FAULT
•
AIR PRESSURE ERROR
5.3 Service Indicator
The burner will indicate when a service is required by showing the word ‘SERVICE’ on the control panel display.
This will occur after a preset period (500 hours of pellet auger running time) has elapsed. This equates to the consumption of 6 tonnes of pellets.
The boiler must be serviced either annually, or when you see the ‘SERVICE’ message on the burner control panel display, whichever comes first.
Contact you Grant Approved Installer and arrange for your boiler to be serviced.
5.4 Active Symbols
There are eight symbols on the left hand side of the burner control panel display.
These are the ‘active symbols’ that, when they have a cursor displayed next to them in the screen area, indicate what functions the burner is
operating at any point when the boiler is running.
Figure 5-4: Burner control panel display – active symbols
The function indicated by each of these ‘Active Symbols’ is as follows:
Symbol
Function
Heating demand (from heating system controls)
Burner fan operational
Air pressure switch closed
Ignition element operational
Pellet feed auger operational
Flame on
Not applicable
Fault
Table 5-5: Active symbols
