Laars MASCOT FT MFTCW Installation And Operation Instructions Manual page 66

Page 64
This controller is able to record information about the boiler's condition at the time of the five previous faults or
errors. Refer to the Section '5.10 Error Mode' of this manual.
Display
Nothing shown
on display control
panel and blower
running at full
speed.
Nothing is shown
in display control
panel and no
other boiler
components are
operating.
Nothing is shown
on
control panel, but
boiler is
operating.
Condition
Control is not
receiving power.
Control is not
receiving 120V power.
Occurs when the
communication is lost
from the control to the
display.
Diagnostic
Check wiring for short
circuit or incorrect
wiring.
Check transformer
connection to the
control per wiring
diagram. Check for
12V output of
transformer.
Check service switch
and/or circuit breaker
to boiler turned is on.
Is there 120 Volts at
the service switch?
Is the ON/OFF
POWER
SWITCH (inside boiler
case) turned on?
Check for 120 volts at
the line voltage
terminal block located
inside the boiler case.
Inspect the fuse.
Replace if necessary.
Check for loose
connections and
proper pin alignment/
engagement on the
Control's plug.
Cycle power off and on
using boiler power
switch and check for
operation.
LAARS Heating Systems
7.2 Suggested Corrective Actions
Corrective Action(s)
Correct wiring per wiring diagram
including connection of transformer to
the control.
Replace transformer if it is receiving
120V, but not outputting 12Vac.
Turn on service switch to power boiler.
Troubleshoot and correct the power
supply to the manual switch.
Turn ON the manual power switch
inside the boiler case.
Correct wiring inside the boiler case
using the wiring diagram in this
manual.
Replace the fuse with proper part
found in the replacement part section
of this manual. If fuse blows again
recheck wiring per diagram.
Check for continuity on the wire
harness from the display to the control.
See repair parts section for proper
replacement part.
Replace with new display module. See
repair parts section for proper
replacement part.