Thermal Solutions APEX APX425C Installation, Operating And Service Instructions page 123

12
Troubleshooting
C. Soft Lockout (Hold)
From the Help menu, select the blinking Soft Lockout (Hold) icon to determine the cause of the soft lockout. See
Figure 12-2. The boiler will automatically restart once the condition that caused the lockout is corrected.
The Soft Lockout (Hold) screen will display the hold number, name, condition that caused the hold, possible
causes, and a basic description of corrective actions that may be taken to fix the problem. An in-depth guide to
possible soft lockouts is provided in Table 12-3.
Table 12-3: Soft Lockout (Hold) Codes
Lockout
Number
Minimum time between starts has
1
not been reached. Normal delay
Anti-Short Cycle
used to avoid excessive cycles.
2
Boiler Recycling
LCI safety limit input not energized.
Limits Open
(LCI OFF)
3
Burner Interlock ILK safety limit input not energized.
Open (ILK OFF)
4 Supply temperature exceeds
Outlet/Supply Preferred Supply High Limit minus
High Limit Stepped Modulation Recycle
Offset, default 200°F (93.3°C).
Flue temperature exceeds
6
Preferred Stack High Limit minus
Stack High Limit
Stepped Modulation Recycle
Offset, default 194°F (90°C).
106308-05 - 3/23
(continued)
Figure 12-2: Example Soft Lockout
Condition
Faulty contact provided by the EMS system.
Limit Control Input (LCI) is not ON. Refer to Limit String Status screen
for list of limits.
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•
•
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Lockout input (ILK) is not ON. Refer to Limit String Status screen for
list of limits.
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•
•
•
•
•
•
•
•
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APEX Installation, Operating, & Service Instructions
Possible Cause
Auto Reset Ext. Limit device open or jumper not installed
Low water condition (if using 24V LWCO)
Flow switch open. Check boiler pump and flow switch wiring.
Sump pressure switch open. Check for vent or combustion air
pipe blockage.
Condensate float switch open. Check for condensate drain
blockage.
Loose or defective limit string wiring
Man Reset Ext. Limit device open or jumper not installed
High or low gas pressure switch open or jumper not installed
Thermal link open
Burner door thermostat open
Loose or defective limit string wiring
Heating load much less than boiler minimum firing rate.
Defective system pump or no flow in primary loop.
Defective boiler pump, no flow or insufficient flow in boiler loop.
Control system miswired so that the boiler operation is permitted
when no zones are calling.
Heat exchanger needs to be cleaned
Boiler over-fired
Air-fuel mixture out of adjustment
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