Laars mascot ft MFTHW, Installation And Operation Instructions Manual

Page: 75 / 96

Mascot FT, Heating Only, Boiler Page 73
Fault Condition Diagnostic Corrective Action(s)
TEMPERATURE
SENSOR
Occurs when a
temperature
sensor has
electrically
shorted
(SHORT) or has
become
disconnected
(OPEN).
Reset using manual
reset screen on
Control Display.
(Power button)
Check all the temperature readings of
the boiler on the DIAGNOSTICS
- TEMPERATURES menu to determine
if any sensors are currently displayed
as SHORT or OPEN.
Check wire harness for loose
connections and pin engagement at
sensor Connection and Control
module.
If problem persists after checking items
above replace Control. Refer to repair
parts section for kit number.
FLAME FAULT
Occurs when
flame is
detected when
there should be
no flame.
Reset using manual
reset screen on
Control Display.
(Power button)
Burner may be operating too hot due
to incorrect combustion. Inspect flame
and conduct combustion test.
Check for flame at burner via flame
current with burner off. Turn boiler off
and watch flame through observation
port. If flame continues after shutdown
replace gas valve.
BLOWER FAULT
Blower unable
to reach
required speed
or does not
reach 0 RPM
when turned off.
Reset using manual
reset screen on
Control Display.
(Power button)
Check wire harness for loose
connections and pin engagement at
blower.
Connections.
Boiler in standby mode and blower not
running. If BLOWER SPEED is not 0
RPM then replace blower.
If blower does not rotate during ignition
sequence check for 120V power at
blower connection. If 120Vac power at
blower motor and it doesn't start
replace blower. Check power at
Control. If 120Vac is not present at
Control when boiler is powered replace
Control.
IGNITION
FAULT
Even if boiler
went through 8
ignitron
attempts, but
cannot detect
flame
Power off and on.
Dirty burner and/or heat exchanger will
cause high back pressure and poor
ignition.
Visual inspection of flue ways often will
not be able to diagnose condition.
Check incoming gas pressure with
boiler off and at Max fire. Adjust within
limits on rating label.
Check for flue pipe and intake pipe
restrictions or blockage
Check burner fasteners and gaskets
Check air intake pipe and proper
propane orifice
GAS VALVE
FAULT
The Control has
detected a
problem with it
gas valve
output circuit.
Reset using manual
reset screen on
Control Display.
(Power button)
Check wire harness connections
between gas valve and Control.
If lockout re-occurs replace Control.
7.2 Suggested Corrective Actions
(continued)