Crown Boiler BWC151 Manual De Usuario
71
B. Trouble shooting problems where a soft lockout code is displayed. When a soft lockout occurs, the boiler will
shut down and the display will alternate between the number “9” and the letter “b” followed by a two digit
service code. The boiler will automatically restart once the condition that caused the lockout is corrected.
CODE
CONDITION
POSSIBLE CAUSES
b 08
Pressure switch circuit open.
• Blockage in intake or vent system.
• Vent and/or intake system not constructed in accordance
• Vent and/or intake system not constructed in accordance
with Part VII.
• Blocked or leaking pressure switch tubing.
• Heat exchanger or burner blockage.
• Terminals exposed to high winds.
• Blockage in condensate trap above vent.
• Heat exchanger or burner blockage.
• Terminals exposed to high winds.
• Blockage in condensate trap above vent.
b 18
MCBA supply sensor detected temperatures in excess
of 200°F.
of 200°F.
• Heating load at time of error was far below the minimum
firing rate of the boiler.
• Defective primary pump or no flow in primary loop (Piping
Method 1).
• Control system miswired so that boiler operation is
permitted when no zones are calling.
b 19
MCBA return sensor detected temperatures in excess of
200°F.
200°F.
• See possible causes for “b18”.
• Flow through boiler reversed.
• Sensor wiring reversed.
• Flow through boiler reversed.
• Sensor wiring reversed.
b 24
MCBA is reading a return sensor temperature higher
than the supply sensor temperature. Condition must be
present for at least 75s for this error code to appear.
than the supply sensor temperature. Condition must be
present for at least 75s for this error code to appear.
• Flow through boiler reversed. Verify correct piping and
pump 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.
• Supply or return sensor defective.
b 25
Supply water temperature has risen too quickly.
• See possible causes for “b18”.
• Inadequate boiler water flow. Verify that pump is
• Inadequate boiler water flow. Verify that pump is
operating and that pump and piping are sized per Part IX
of this manual.
of this manual.
b 26
Boiler safety limit, or external limit wired across terminals
3&4, is open.
3&4, is open.
• See possible causes for “b18”.
• Defective supply sensor.
• Defective supply sensor.
b 30
Temperature rise between supply and return is too high.
• Inadequate boiler water flow. Verify that pump is
operating and that pump and piping are sized per Part IX
of this manual.
of this manual.
b 61
Pressure switch circuit closed with fan off.
• Blockage in pressure switch hose.
• Pressure switch wires shorted together.
• Defective pressure switch.
• Loose or miswired fan speed harness (if “b61” error code
• Pressure switch wires shorted together.
• Defective pressure switch.
• Loose or miswired fan speed harness (if “b61” error code
is observed while fan is running).
b 65
Fan is not achieving set point speed.
• Loose or incorrect fan speed control connection.
• Defective fan.
• Defective fan.
Table 14.3: Soft Lockout Codes Displayed