Crown boiler troubleshooting

Below you will find Crown boiler troubleshooting chart. This is a very useful table allowing to conduct diagnostics of an appliance quickly and productively and determine the complexity of repairs during its malfunction. Refer to it every time error codes appear on the display of any Crown appliance.

Crown CRN2 boiler troubleshooting

Unit not heating but power light on.Vent thermostat open, due to over flowing or over boiling.Replace vent thermostat. If unit over boiling. Replace thermistor. If problem persists replace circuit board.
Unit not giving water from the tap.Tap broken. Water not turned on, Electric inlet valve coil burned out, circuit board faulty.Replace tap insert. Turn water on and test unit. Replace water inlet valve and test unit. Replace circuit board and test unit.
Unit not working properley.Power point not wired up correctlyCheck terminal connections.
1. Active top left terminal
2. Neutral top right terminal
3. Earth centre terminal

Crown TWZ065 boiler troubleshootings

Error CodeMeaningPossible Cause
1Temperature Sensor FaultLoose connection between sensor and control • Sensor wire damaged Defective Sensor Defective control
2Communication Fault• EnviraCOM wiring is shorted to ground or line voltage
• Field wiring to external Enviracom device is incorrect.
3Internal electronics failure• AC powrer supply frequency problem
Possible internal problem with boiler control. Cycle power to the boiler and replace control if problem persists.
4Burner Output (B1) Fault• Application of power to B1 from external source (control miswired)
• Possible internal problem with boiler control. Cycle power to the boiler and replace control if problem persists.
5Line voltage error (Supply voltage too high or low)Powrer supply voltage is incorrect (should be 120VAC nominal)
6Open fuse in L7248L or L7224A• Incorrectly wired burner primary control (See Section X).
7User settings lost (reset to factory defaults)Clear error by entering and exiting the Adjustment mode (and changing set- tings back to user values as needed). Replace control if problem persists.
8Manual Reset Lockout• Set if Err 4 was invoked four times in a row. Check wriring and clear Lockout by pressing all three user keys for 60 seconds.
StA 1
hr OFF
dh OFF
Burner and Circulator Off• Thermostat/s not calling for heat
• Loose connection in thermostat, zone valve end switch, or zone panel wiring.
• Thermostat, zone valve, or zone panel miswired
• Defective thermostat, zone valve, or zone panel
StA 1
hr 0n
Burner Off Circulator On Boiler Warm• Boiler off on high limit (normal operation)
• Boiler off on thermal purge (normal operation - See Table 12.6)
hr OnHeating Circulator Off• Heating Circulator is being forced off on DHW priority (normal operation if Pfc=<)N - see Table 12.7).
• See causes for “DHW Circulator off“ below
dh OnDHW
Circulator Off
• Loose connection in circulator wiring
• Defective circulator
• Circulator is running, but system problem is preventing circulation
StA BBurner Off No LEDs illuminated on Burner Primary control• External Limit or LWCO is open.
• Burner is unplugged
• Loose connection between B1-B2 on L7248L or L7224A and burner
• Loose or missing T-T jumper on burner primary control.
StA BBurner Off LED is illuminated on Burner Primary control• Consult burner documentation for cause of problem.

Error codes and troubleshooting