Cooling fan
Common VFD, drive, UPS, and cabinet overheating failure point.
Tuttnauer Autoclave Fault Codes - Quick Reference
Tuttnauer autoclaves (2340, 3870, Elara, Valueklave, and EZ10 series) display fault codes on the digital or LED display panel. Common in dental, veterinary, and laboratory settings.
| Code | Model | Meaning | Quick Fix |
|---|---|---|---|
| E1 | All | Temperature sensor fault | Check sensor wiring and resistance |
| E2 | All | Pressure sensor fault | Check transducer signal |
| E3 | 2340/3870 | Temperature not reached in time | Check steam supply and door seal |
| E4 | All | Overpressure safety fault | Check safety valve |
| E5 | All | Door not closed or locked | Check door and locking mechanism |
| E6 | Electronic | Memory/EEPROM fault | Contact service |
| E7 | Elara | Water level fault | Check water reservoir |
| E8 | Elara | Conductivity fault | Check water quality (use distilled) |
| E9 | EZ10 | Printer fault | Check printer paper/connection |
| LO | Display | Low water level | Refill with distilled water |
Most Common Faults
E1 - Temperature Sensor Fault
Tuttnauer uses PT100 temperature sensors in the chamber. An E1 fault means the sensor is reading out of range - either a broken wire (reads too high) or a short (reads too low). Disconnect the sensor and test resistance: 100 ohms at 0°C, approximately 138 ohms at 100°C. Replace the sensor if values are incorrect.
E3 - Temperature Not Reached
If the autoclave doesn’t reach the target temperature (121°C or 134°C) within the preset time, E3 aborts the cycle. This is commonly caused by: door not sealing fully (check gasket), low steam generation from a scaled heating element, or insufficient water. Descale the unit if limescale buildup is visible.
E5 - Door Fault
Tuttnauer door faults indicate the door locking mechanism didn’t complete. On manual-lock models, ensure the door handle is fully rotated to the locked position. On automatic-lock models, check the door solenoid and locking cam. A worn door gasket that lets steam escape also prevents the door from locking under pressure.
E7 / LO - Water Level Fault
Elara and EZ10 models have internal water reservoirs with level sensors. Always use distilled or RO water - tap water causes mineral scaling that damages the heating element and clogs the strainer. Clean the water reservoir and level sensor if false water level alarms occur with a full reservoir.
E8 - Conductivity Fault (Elara)
Elara models test water conductivity to prevent mineral buildup damage. If tap water or inadequately treated water is used, E8 triggers and the cycle is aborted. Use only distilled or deionized water with conductivity below 15 µS/cm.
Parts Often Needed
| Part | Notes |
|---|---|
| PT100 temperature sensor | Replace on E1 |
| Door gasket (silicone) | Replace on E5 / poor sealing |
| Heating element | Replace on slow heat-up |
| Safety valve | Replace on overpressure fault |
| Level sensor | Replace on false LO alarm |
Need Replacement Parts?
Before ordering, match the commercial equipment part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
Tuttnauer autoclave spore testing, cycle validation, and annual PM require trained biomedical technicians. In dental and medical practices, sterilizer validation records are required by regulatory bodies.