Weil-McLain Evergreen EVG 110, Manual

Page: 113 / 144

Troubleshooting
(continued)
Figure 99 Troubleshooting suggestions for EVG boilers — Fault displays, diagnostics and corrective actions
Part number 550-100-191/0917
113
®
g
as-fired water boiler —
70/110/155
Boiler Manual
Display
Condition Diagnostics Corrective Action(s)
LIMIT OPEN
Occurs if manual or automatic
reset limit opens. Automatic external limit will
reset 2½ minutes after external
limit device closes.
Manual limit fault must be reset
by choosing Manual Reset on
the display.
Is there an external safety device connected? If yes, trouble shoot the
external limit to determine and correct the cause that opened the limit.
Also check for loose wiring connections.
Inspect the connector on the control module plug P13.
Ensure a jumper is installed across the MAN LIMIT (Pins 1 & 2) terminals if
not using a manual reset external limit.
Ensure a jumper is installed across the AUTO LIMIT (Pins 3 & 4) terminals if
not using a automatic reset external limit.
HIGH TEMP
LIMIT
Boiler temperature sensor
reached High Temp Limit
setting (no higher than 200° F). Reset using manual reset screen
on display. Verify that high limit setting is at least 10° F above the maximum target
temperature plus the off diff erential .
Verify all isolation valves are open and circulators are programmed into
the control properly.
The boiler circulator output and System Pump/Aux. output can be
confi gured to turn on or off with each priority. Refer to the Control Setup
section to confi gure these properly for the system.
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.
FLAME FAULT
Occurs if fl ame is detected
when there should be no
fl ame. Reset using manual reset screen
on display. Burner may be operating too hot due to incorrect combustion. Inspect
fl ame and conduct combustion test.
Force boiler into high fi re. Check fl ue 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 fl ame at burner via fl ame current with burner off . Turn boiler
off and watch fl ame through observation port. If fl ame continues after
shut down replace gas valve.
GAS VALVE
FAULT
The control has detected
a problem with gas valve
output circuit. Control will do automatic 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.
If lockout reoccurs replace control.
BLOWER FAULT Blower unable to reach
required speed or does not
reach 0 RPM when turned off . Reset using manual reset screen
on display; Control will check
again after 1 hour and will
automatically restart if condition
is corrected. Check wire harness for loose connections and pin engagement at
blower connections, chassis mount connection through control housing,
and control. Unplug connection at blower and at control 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 then replace blower.
If blower does not rotate during ignition sequence check for 120V power
at blower connection. If 120 VAC 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. Refer to repair parts
section.