Burnham Apex APX399 Installation, Operating And Service Instructions page 107

Xii. Troubleshooting
F.
Troubleshooting problems where a Soft Lockout Code is displayed. When a soft lockout occurs, the boiler will shut
down, the display will turn red and the "Help" button will "blink". Select the "blinking" "Help" button to determine the
cause of the soft lockout. The boiler will automatically restart once the condition that caused the lockout is corrected.
Soft Lockout Codes Displayed
Lockout
number
1 Minimum time between starts has not been reached.
Anti Short Cycle Normal delay used to avoid excessive cycles.
Boiler Safety Limit wired to terminals J6-1, 2 or 3
OPEN:
• Condensate Trap Float Switch
contact open.
2
• Thermal Link Switch contact open.
Boiler Safety Limit
Open • Burner Door Thermostat with manual reset
contact open.
• Air Pressure Switch contact open.
• Auto Reset High Limit contact open.
Boiler Safety Limit, or External Limit wired to
terminals J5-1 OPEN:
• Jumper for External Limit wired to terminals 11
3
and 12 or device connected to it open.
Boiler Safety Limit
• Jumper for Low Water Cutoff (LWCO) Switch or
Open
device connected to it open.
• Jumper for Low Gas Pressure Switch or device
connected to it open.
7
Shorted or open return temperature sensor.
Return sensor fault
8
Shorted or open supply temperature sensor.
Supply sensor fault
9 Shorted or open Domestic Hot Water (DHW)
DHW sensor fault temperature sensor.
10
Shorted or open flue gas (stack) temperature sensor.
Stack sensor fault
11
Flame failure after 5 tries to restart.
Ignition failure
13
Flame rod Flame rod shorted to ground
shorted to ground
14 Temperature rise between supply and return is too
DT inlet/outlet high high.
The Control is reading a return sensor temperature
15
higher than the supply sensor temperature. Condition
Return temp higher
must be present for at least 75 seconds for this error
than supply
code to appear.
16
Supply temp has risen Supply water temperature has risen too quickly.
too quickly
17
Normal waiting for blower speed to match purge and
Blower speed not
light-off setpoint.
proved
(continued)
Condition Possible Cause
• Loose wiring to limit device.
• Auto Reset Supply high limit sensor detected temperature in excess of 200°F.
• Defective Auto Reset Supply High Limit Switch.
• Plugged Condensate Trap - also check to ensure boiler is level.
• Thermal Link Switch blown due to temperature rise above 604°F (318°C).
• Burner Door Thermostat with manual reset contact open due to temperature rise
above 500°F (260°C) - check the cause of overheating (burner door insulation, loose
mounting, etc.).
• Air Pressure Switch contact open - check for blocked vent.
• See possible causes for "Hard Lockout 4".
Block Vent Special Note
Before a call for heat the air pressure switch is closed. When there is a call for heat
with a blocked vent the air pressure switch will open (due to excessive pressure of the
blower against a blocked flue pipe) after the blower starts. The control stops the start
sequence and stops the blower. After the blower stops the pressure switch re-closes
and the cycle continues. The displays shows the cause of trip for only the time the
pressure switch is open.
• See possible causes for "Hard Lockout 4".
• Loose wiring to limit device.
• External Limit defective or jumper not installed.
• Low Gas Pressure Switch contact open (if installed).
• LWCO switch not installed and jumper missing.
• If yellow light on LWCO is on, system is low on water.
• If neither yellow or green light is on, check LWCO harness.
• Shorted or mis-wired return sensor wiring.
• Defective return sensor.
• Shorted or mis-wired supply sensor wiring.
• Defective supply sensor.
• Shorted or mis-wired DHW sensor wiring.
• Defective DHW sensor.
• Shorted or mis-wired stack sensor wiring.
• Defective stack sensor.
• No gas pressure.
• Gas pressure under minimum value shown on rating plate.
• Gas line not completely purged of air.
• Defective Electrode.
• Loose burner ground connection.
• Defective Ignition Cable.
• Defective gas valve (check for 24 Vac at harness during trial for ignition before
replacing valve).
• Air-fuel mixture out of adjustment - consult factory.
• Shorted or mis-wired flame rode wiring.
• Defective flame rod.
• Inadequate boiler water flow. Verify that circulator is operating and that circulator
and piping are sized per Section VI of this manual.
• Flow through boiler reversed. Verify correct piping and circulator orientation.
• No boiler water flow. Verify that system is purged of air and that appropriate valves
are open.
• Sensor wiring reversed.
• Supply or return sensor defective.
• See possible causes for "Hard Lockout 4".
• Inadequate boiler water flow.
• Verify that circulator is operating and that circulator and piping are sized per
Section VI of this manual.
NOTE
107