Grant Spira Series - Page 66

Fault Finding
66
12 Fault Finding
Note 1 - Is the fault cleared by
pressing the reset button?
Is the pellet feed tube less than 60°C?
If not then allow it to cool before
proceeding.
When cool, remove the steel retaining
clip and disconnect the lead from the
pellet feed tube (burn back) thermostat.
Press the reset button on the
thermostat.
Note 2 - Is feed pipe thermostat
(burn back sensor) damaged or
faulty?
Check the electrical continuity and
condition of the thermostat. Replace if
necessary.
Note 3 - Is the pellet delivery hose
damaged/correctly fitted?
Check the condition of the hose. Is it
damaged? If so replace it.
Is it fitted correctly at both ends – with
an air tight fit onto both pellet feed pipe
and pellet auger outlet? Rectify as
necessary.
A damaged (or incorrectly fitted)
pellet delivery hose can allow a back
draught through the boiler, resulting
in the pellet tube (burn back)
thermostat operating and shutting
down the burner.
Note 4 - Is the ash pan overflowing?
An overflowing ash pan, and ash build-
up on the baffle, can block the passage
of the combustion gases from the
burner, causing them to back-up
through the burner into the pellet feed
tube. This will activate the pellet feed
tube (burn back) thermostat.
The ash pan must be periodically
emptied, and also any ash build-up on
the baffle removed, by the user at
MONTHLY intervals for the FIRST
THREE MONTHS. After this the ash
pan should be emptied, and ash on the
baffle removed, regularly, on at least a
monthly basis, or as indicated by the
amount of ash found during the first
three months cleaning. Refer to Section
1.5.
Note 5 - Is combustion chamber
draught correct?
Check combustion chamber draught.
Refer to Section 10.9 for procedure.
If it is incorrect, BEFORE making any
adjustment to the draught stabiliser,
carry out the following checks as per
the flow chart:
• Is condensate trap or pipework
blocked or frozen? Defrost/remove
blockage as necessary.
• Is ash pan overflowing? Empty and
clean ash pan as necessary.
• Is the flue system incorrectly
installed or blocked? Rectify as
necessary.
• Is the flue fan operational?
• Is the room ventilation adequate?
If all the above are OK, then adjust the
draught stabiliser as necessary to
achieve the required combustion
chamber draught. Refer to Section 10.9
for procedure.
Note 6 - Is condensate trap/pipe
blocked?
Thoroughly check the entire
condensate disposal system, including
all the pipework and the trap(s), to
ensure that it is not blocked or frozen
(even partially).
If the condensate backs-up into the
condensing heat exchanger, it can
block the passage of the combustion
gases from the burner, causing them to
back-up through the boiler and burner
into the pellet feed tube. This will
activate the pellet feed tube (burn back)
thermostat.
Note 7 - Is the flue correct type and
correctly installed?
Only the Grant Black flue system can
be used with the Grant Spira wood
pellet boilers. Check that the flue has
been correctly assembled and that the
terminal position complies with the
requirements of The Building
Regulations – Approved Document J.
Refer to Sections 7.2 for guidance.
Note 8 - Is flue fan operational and
clean?
If the flue fan is not running, or is
coated with ash, the draught in the
combustion will be reduced causing the
combustion gases from the burner to
back-up through the burner into the
pellet feed tube. This will activate the
pellet feed tube (burn back) thermostat.
Note 9 - Is the room ventilation
adequate?
Check that sufficient permanent
ventilation is present in the room
containing the boiler(s). Refer to Section
7.1 for guidance.
Lack of ventilation will lead to
incomplete combustion, and an
increased temperature in the pellet feed
tube that will activate the burn back
thermostat.
Note 10 - Is the wash system
operating correctly?
Check the water supply to the wash
system is connected and turned on.
Operate the CLEANING switch and
check the solenoid valve is opening and
the water jets are all clear and spraying
into heat exchanger tubes. Refer to
Section 10.3.3.
If necessary remove, clean and refit the
wash system manifold. Refer to Section
11.6.2.
In hard water areas an anti-scale device
should be fitted on the cold water
supply to the wash system to prevent
scale build-up in the manifold and jets.
Note 11 - Is the boiler cleaning
period correct?
Go to the ‘CLEAN’ sub menu of the
burner control settings and check that
both ‘TIME CLEAN PERIOD’ and
‘TIME CLEAN BOILER’ are correctly
set. If not, re-set to the correct value.
Refer to 9.7.1.3.
12.5 Pellet Tube Thermostat