Weil-McLain Series 2 Manual page 101

® S
ERIES
Troubleshooting
Figure 108 Troubleshooting suggestions for ECO boilers — Fault displays, diagnostics and corrective actions
Condition
Display
Boiler temperature sensor
HIGH TEMP
reached High Temp Limit
LIMIT
setting (no higher than
200°F).
Occurs if flame is detected
FLAME FAULT
when there should be no
flame.
The control module has
GAS VALVE
detected a problem with its
FAULT
gas valve output circuit.
BLOWER FAULT Blower unable to reach
required speed or does not
reach 0 RPM when turned
off.
NOTICE: ECO 70 or 110 only
— The blower will not rotate
without a low voltage signal.
Unplugging the low voltage
blower wire harness will not
allow or cause the blower
to rotate.
Part number 550-142-190/1218
2
-
G
AS FIRED WATER BOILER
(continued)
Diagnostics
Reset using manual reset screen
on display.
Reset using manual reset screen
on display.
Control will automatically retry;
lockout if retry unsuccessful;
retry 1 hour after lockout —
restart if condition cleared, but
lockout requiring manual reset if
condition still present.
Requires manual reset if control is
in lockout.
Reset using manual reset screen
on display; control module will
check again after 1 hour and will
automatically restart if condition
is corrected.
— Boiler Manual
Corrective Action(s)
Verify that high limit setting is at least 10°F above the supply target
temperature (DHW Boiler Supply and Heating Supply Max).
Verify all isolation valves are open and circulators are connected to the
control module properly.
Verify external controls are installed per manufacturer's instructions, all
applicable codes, and sound industry practices.
Verify water pipe is installed correctly per instructions in this manual.
Verify proper circulator sizing for boiler size and system requirements.
See message displayed TEMPERATURE SENSOR and follow procedure for
loose connections.
Burner may be operating too hot due to incorrect combustion. Inspect
flame and conduct combustion test.
Force boiler into hi-fire. Check flue gases with combustion analyzer and
correct using the maintenance and startup procedure in this manual.
Verify FLAME SIGNAL value quickly goes to zero on the DIAGNOSTICS -
INPUTS screen when the gas valve closes.
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 and venturi.
Check wire harness connections between gas valve and control module.
Check resistance between control and gas valve.
Disconnect low-voltage wires connected to the low voltage field-wired
connectors. Check all wire leads from system from system for stray
voltage. Any voltage in excess of 0.5 volts will cause gas valve fault
failures. Correct the cause of stray voltages before reconnecting wires.
After correcting problem, check to see if gas valve fault issue is corrected.
If lockout reoccurs replace control module.
Check wire harness for loose connections and pin engagement at
blower connections and control module. Unplug connection at blower
and at control module and check continuity between ends. Blower is
connected to both low voltage and line voltage harness.
Check Diagnostics - Inputs screen with boiler in standby mode and
blower not running. If BLOWER SPEED is not 0 RPM replace blower.
If blower does not rotate during ignition sequence check for 120V power
at blower connection. If 120VAC power is present at blower motor and it
doesn't start, replace blower. Check power at control module. If 120VAC
is not present at control module when boiler is powered, replace control
module. Refer to repair parts section.
101