NEW! TROUBLESHOOTING THE TUTTNAUER WATER PUMP

Troubleshooting Guides for all Tuttnauer "E" Series Autoclaves - Including Models 1730E, 1730EK, 2340E,2340EA, 2340EK, 2340EKA, 2540E, 2540EA, 2540EH, 2540EHS, 2540EK, 2540EKA, 3870E, 3870EA, 3870EH, 3870EHS, EZ9 & EZ10)

How To Troubleshoot The Tuttnauer Water Pump

This Troubleshooting Guide Is For Those Tuttnauer Autoclaves With A Water Pump. Tuttnauer Autoclaves with Microprocessors that have a date code containing the letters "WP" will have a Water Pump installed

Tuttnauer Water Pump Symptom Testing Procedure/Solution
Pump Does Not Turn On
  • Check the Water Pump Fuse with an ohm meter, if needed replace with a 1.2 amp fuse.
  • The Water Pump Fuse is located above the two line voltage Fuses or the Circuit Breaker at the back of the autoclave.
  • Check for a pinched wire or other open in the power leads going from the Water Pump Solid State Relay to the Water Pump. The Water Pump Solid State Relay is located in the Electronic Box, terminals 3 and 4 are connected to JP15.


  • Turn the power off, remove the wires connected to terminals 1 and 2 of the Water Pump Solid State Relay. Connect these two wires together and turn the power back on.
    • If the pump runs then the problem is with either the Water Pump Solid State Relay or the control circuit
    • If the Water Pump does not run the problem is with the pump and it should be replaced.


  • Check if the Water Pump Solid State Relay is being told to turn off.
    • With a Volt/Ommeter read between TP13 and TP1, a 10 to 12 volt DC signal tells the Water Pump Solid State Relay to turn off and 0 to 1 volts tells it to turn on.
    • An incorrect signal would indicate a problem with the control circuit
    • If the control signal is correct at the test point then check if the signal is at the Water Pump Solid State Relay
    • A reading across terminals 3 and 4 should show 10 to12 volts DC for the Water Pump Solid State Relay to be turned on and 0 to 1 volt if it should be off
    • If the control signal is not correct at the Water Pump Solid State Relay then the problem is with the Ajunc board and it should be replaced
Pump Does Not Turn Off
  • Check if the Water Pump SSR is being told to turn off.
    • With a Volt/Ohmmeter read between TP13 and TP1, a 10 to 12 volt DC signal tells the Water Pump Solid State Relay to turn off and 0 to 1 volts tells it to turn on.. An incorrect signal would indicate a problem with the control circuit
    • If the control signal is correct at the test point then check if the signal is at the Water Pump Solid State Relay. A reading across terminals 3 and 4 should show 10 to 12 volts DC for the Water Pump Solid State Relay to be turned on and 0 to 1 volt if it should be off
    • If the control signal is not correct at the Water Pump Solid State Relay then the problem is with the Ajunc board and it should be replaced
Water Pump Blows Fuse
  • Check for a pinched wire or other ground short in the power leads going from the Water Pump Fuse to the Water Pump.
    • Turn off the power and disconnect the wires from terminals 1 & 2 on the Water Pump Solid State Relay.
    • Turn the power back on , if the fuse blows again the problem is with the Water Pump or the pump capacitor and both should be replaced.
Pump Makes Noise
  • Check if Water Pump mounting bracket is loose or broken. Replace the pump bracket If the pump bracket is not loose or broken then replace the Water Pump
Pump Does Not Pump Water
  • Is the Pump Strainer clogged? Clean the Pump Strainer and run the Water Pump using the Water Inlet Key.
    • If water is now being pumped then the problem was a clog in the Pump Strainer
    • Check if the Fill Solenoid is being activated.
      • Place a steel object like a screwdriver on the center post of the Fill Solenoid to detect a magnetic field. If a magnetic field is detected then the solenoid has been turned on.
      • If no magnetic field is detected then Listen for a click at the Fill Solenoid when the Water Pump turns on. A click will indicate that the solenoid should be open.
      • If there is no click then Open the Fill Solenoid Valve, remove the plunger and reinstall the housing only. Press the Water Inlet Key. If water is pushing through to the Chamber then the problem is with the Plunger. Replace The Plunger
      • If not then remove the housing. Again press the Water Inlet Key if water is pushing through to the valve base then the problem is in the tubing from the valve base to the Chamber.
      • If the water is not pushing through to the valve base then the problem is with the tubing from the base to the pump or the Water Pump itself.
      • Replace the pump if necessary.
Water Flows In The Wrong Direction Reverse the two silicone tubes connected to the Water Pump

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