52
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
with Part VI.
• Blocked or leaking pressure switch tubing
• 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
• 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
• See possible causes for “b18”
• 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.
• 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.
b 25
Supply water temperature has risen too quickly
• See possible causes for “b18”
• Inadequate boiler water flow. Verify that pump is
operating and that pump and piping are sized per Part
VIII of this manual
b 26
Boiler safety limit, or external limit wired across terminals
3&4, is open.
• See possible causes for “b18”
• 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
VIII 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
is observed while fan is running)
b 65
Fan is not achieving set point speed
• Loose or incorrect fan speed control connection
• Defective fan
Table 13.3: Soft Lockout Codes Displayed
Summary of Contents for CHG CHG150
Page 25: ...25 Figure 8 3 Piping Method 1 Heat Indirect Water Heater Figure 8 2 Piping Method 1 Heat Only ...
Page 29: ...29 Figure 8 8 Piping Method 2 Heat Only Figure 8 9 Piping Method 2 Heat Indirect Water Heater ...
Page 36: ...36 Figure 9 1 Wiring Connections Diagram ...
Page 37: ...37 Figure 9 2 Ladder Diagram ...
Page 38: ...38 Figure 9 3 Wiring of Isolation Relay for Control of Two Heating Circulators ...
Page 40: ...40 CHG Series Lighting and Operating Instructions ...
Page 46: ...46 Figure 11 2 Basic Menu Tree ...
Page 54: ...54 SERVICE RECORD DATE SERVICE PERFORMED ...
Page 58: ...58 ...
Page 59: ...59 ...
Page 60: ...60 ...
Page 61: ...61 ...
Page 63: ...63 ...
Page 65: ...65 ...
Page 66: ...66 ...
Page 67: ...67 ...
Page 69: ...69 SERVICE RECORD DATE SERVICE PERFORMED ...
Page 70: ...70 SERVICE RECORD DATE SERVICE PERFORMED ...
Page 71: ...71 SERVICE RECORD DATE SERVICE PERFORMED ...
Page 72: ...9EARS IN 3ERVICE 3ERVICE HARGE AS OF 2ETAIL 0RICE O HARGE ...