M3 Sterilizer General System Error Codes: C981 to C987 Troubleshooting

Items Not Sterile message will be displayed if an error occurs in any of the following modes: Close mode, Heat Up Mode, or Sterilize Mode. Otherwise, message will not appear. This message is intended to indicate to the user that the items in the chamber may or may not be sterile, and must be reprocessed.

Display / Symptom Cause Check Action

C981: SELECT MODE BOILER HI-LIMIT OPEN

ITEMS NOT STERILE TURN POWER OFF/ON

Boiler overheat thermostat has opened for at least 0.25 seconds & needs to be manually reset.

 Water pump not primed. Water pump priming instructions. Prime water pump.
Boiler temperature sensor not functioning properly. Temperature Sensor Resistance Test. Replace boiler temperature sensor.
Boiler overheat thermostat disconnected at PC board. Check wire connections at J3 on PC board. Secure wire connections.
Loose or broken wire connections at boiler overheat thermostat. Check wire connections at boiler overheat thermostat. Secure wire connections.
Boiler overheat thermostat tripped open prematurely. Check if overheat thermostat can be manually reset with a cooled boiler. Replace overheat thermostat.
Display / Symptom Cause Check Action

C982: CLOSE MODE BOILER HI-LIMIT OPEN

ITEMS NOT STERILE TURN POWER OFF/ON

Boiler overheat thermostat has opened for at least 0.25 seconds & needs to be manually reset.

 Water pump not primed. Water pump priming instructions. Prime water pump.
Boiler temperature sensor not functioning properly. Temperature Sensor Resistance Test. Replace boiler temperature sensor.
Boiler overheat thermostat disconnected at PC board. Check wire connections at J3 on PC board. Secure wire connections.
Loose or broken wire connections at boiler overheat thermostat. Check wire connections at boiler overheat thermostat. Secure wire connections.
Boiler overheat thermostat tripped open prematurely. Check if overheat thermostat can be manually reset with a cooled boiler. Replace overheat thermostat.
Display / Symptom Cause Check Action

C983: HEATUP MODE BOILER HI-LIMIT OPEN

ITEMS NOT STERILE TURN POWER OFF/ON

Boiler overheat thermostat has opened for at least 0.25 seconds & needs to be manually reset.

 Water pump not primed. Water pump priming instructions. Prime water pump.
Boiler temperature sensor not functioning properly. Temperature Sensor Resistance Test. Replace boiler temperature sensor.
Boiler overheat thermostat disconnected at PC board. Check wire connections at J3 on PC board. Secure wire connections.
Loose or broken wire connections at boiler overheat thermostat. Check wire connections at boiler overheat thermostat. Secure wire connections.
Boiler overheat thermostat tripped open prematurely. Check if overheat thermostat can be manually reset with a cooled boiler. Replace overheat thermostat.
Display / Symptom Cause Check Action

C984: STERILIZE MODE BOILER HI-LIMIT OPEN

ITEMS NOT STERILE TURN POWER OFF/ON

Boiler overheat thermostat has opened for at least 0.25 seconds & needs to be manually reset.

 Water pump not primed. Water pump priming instructions. Prime water pump.
Boiler temperature sensor not functioning properly. Temperature Sensor Resistance Test. Replace boiler temperature sensor.
Boiler overheat thermostat disconnected at PC board. Check wire connections at J3 on PC board. Secure wire connections.
Loose or broken wire connections at boiler overheat thermostat. Check wire connections at boiler overheat thermostat. Secure wire connections.
Boiler overheat thermostat tripped open prematurely. Check if overheat thermostat can be manually reset with a cooled boiler. Replace overheat thermostat.
Display / Symptom Cause Check Action

C986: OPEN MODE BOILER HI-LIMIT OPEN

ITEMS NOT STERILE TURN POWER OFF/ON

Boiler overheat thermostat has opened for at least 0.25 seconds & needs to be manually reset.

 Water pump not primed.

Water pump priming instructions.

 Prime water pump.
Boiler temperature sensor not functioning properly. Temperature Sensor Resistance Test. Replace boiler temperature sensor.
Boiler overheat thermostat disconnected at PC board. Check wire connections at J3 on PC board. Secure wire connections.
Loose or broken wire connections at boiler overheat thermostat. Check wire connections at boiler overheat thermostat. Secure wire connections.
Boiler overheat thermostat tripped open prematurely. Check if overheat thermostat can be manually reset with a cooled boiler. Replace overheat thermostat.
Display / Symptom Cause Check Action

C987: DRY MODE BOILER HI-LIMIT OPEN

ITEMS NOT STERILE TURN POWER OFF/ON

Boiler overheat thermostat has opened for at least 0.25 seconds & needs to be manually reset.

 Water pump not primed. Water pump priming instructions. Prime water pump.
Boiler temperature sensor not functioning properly. Temperature Sensor Resistance Test. Replace boiler temperature sensor.
Boiler overheat thermostat disconnected at PC board. Check wire connections at J3 on PC board. Secure wire connections.
Loose or broken wire connections at boiler overheat thermostat. Check wire connections at boiler overheat thermostat. Secure wire connections.
Boiler overheat thermostat tripped open prematurely. Check if overheat thermostat can be manually reset with a cooled boiler. Replace overheat thermostat.