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Manufacturer
Model
What This Guide Helps With
Troubleshooting CPXH temperature alarms, heating concerns, over-temperature behavior, or abnormal temperature display conditions.
Step-by-Step Troubleshooting
Ensure Patient Safety First
Remove the ultrasonic cleaner from active use before troubleshooting.
Do not handle hot solution, drain the tank, or move the unit until the bath temperature is safe.
Expected outcome: No user is exposed to hot solution, electrical risk, or chemical splashing.
Why it matters: CPXH units are heated ultrasonic cleaners, and temperature-related complaints may involve hot solution, steam, or chemical exposure.
Verify the Reported Condition
Confirm what clinical staff reported:
- Temperature alarm
- Bath hotter than expected
- Unit not heating
- Temperature display abnormal
- Heat indicator active but temperature not changing
- Alarm appears only during certain cycles
Expected outcome: The exact symptom is confirmed before parts or repair are suspected.
Check the Temperature Setpoint
Review the programmed temperature setting on the CPXH control panel.
CPXH models are heated units, with listed temperature capability up to about 69°C / 156°F depending on model and configuration. Confirm the setpoint is appropriate for the cleaning process and facility procedure.
Expected outcome: The displayed setpoint matches the intended cleaning temperature.
If the setpoint was accidentally set too high, correct it, allow the bath to stabilize, verify normal operation, and stop.
Compare Displayed Temperature to Actual Bath Temperature
Using a suitable external thermometer, verify the bath temperature away from the tank wall and away from items being cleaned.
Compare the external reading to the CPXH display.
Expected outcome: The displayed temperature is reasonably close to the measured solution temperature.
Why it matters: CPXH temperature readout accuracy is listed as approximately ±3°C / ±5.4°F, so small differences may be normal.
Confirm the Tank Is Filled Correctly
Verify the solution level is at the proper operating level line.
Do not operate the unit with low solution level. Add approved solution if needed.
Expected outcome: The tank is filled to the proper level before heat or ultrasonics are tested.
Why it matters: Low solution level can affect heating performance, temperature sensing, cavitation, and tank protection.
Check for Incorrect Load Placement
Inspect the tank for baskets, trays, instruments, beakers, or containers placed directly on the tank bottom.
Items should be supported by an appropriate basket, tray, or accessory rather than resting directly on the tank floor.
Expected outcome: The load is properly suspended and not interfering with heat transfer or ultrasonic operation.
If correcting the load placement clears the alarm or abnormal behavior, document the finding and stop.
Inspect the Solution Condition
Check for heavily contaminated solution, excessive debris, incorrect chemistry, foaming, or chemical residue.
Replace the solution if it is dirty, mixed incorrectly, or not appropriate for ultrasonic cleaning.
Expected outcome: The bath contains clean, approved solution at the correct concentration.
Why it matters: Solution condition can affect temperature response, cleaning performance, and sensor behavior.
Verify Heat Operation
With the tank properly filled and the unit safely positioned, activate heat and observe:
- Heat indicator behavior
- Temperature rise over time
- Whether the display changes gradually
- Whether an alarm appears immediately or only after heating
Expected outcome: Temperature increases gradually and remains controlled near the selected setpoint.
If the unit heats normally and no alarm returns, return to service after confirming safe operation.
Check for Environmental Heat Sources
Verify the unit is not located near:
- Sterilizers
- Warming cabinets
- Direct sunlight
- HVAC discharge
- Other equipment producing heat
Expected outcome: The cleaner is operating in a normal room environment without external heat influence.
Why it matters: External heat can make the bath appear to overheat or delay cooling.
Inspect Power Source and Cord Condition
Verify the unit is connected to a properly grounded outlet.
Inspect the power cord and plug for damage, loose fit, heat discoloration, or signs of arcing.
Expected outcome: Power is stable and there is no visible electrical damage.
If cord, plug, outlet, or heat damage is found, remove the unit from service and escalate for repair.
Power Cycle and Retest
Turn the unit off, allow it to cool if needed, then restart it.
Re-enter the intended temperature setting and observe whether the alarm or temperature issue returns.
Expected outcome: The unit restarts normally and maintains the selected temperature.
If the alarm clears and does not return during a controlled test, document the test results and return the unit to service per facility policy.
Check for Repeatability
Run a short controlled test with:
- Correct solution level
- No load or a normal approved basket
- Correct setpoint
- External temperature verification
Expected outcome: The temperature display, heater response, and alarm behavior remain normal.
If the alarm repeats under controlled conditions, stop troubleshooting and escalate.
If the Problem Persists
If the temperature alarm or abnormal heating condition remains after verifying setpoint, solution level, load placement, solution condition, outlet, cord, and external temperature, the likely cause is internal.
Possible internal causes may include heater control failure, temperature sensor fault, control board issue, wiring issue, or protective temperature circuit problem.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
Knowing when to stop is proper troubleshooting. Do not bypass alarms, defeat heat protection, or continue using a CPXH unit that cannot control or accurately report bath temperature.
Clinical Use Tip
Do not troubleshoot a hot ultrasonic cleaner while staff are actively processing instruments. Let the bath cool, use PPE appropriate for the cleaning solution, and provide an alternate cleaner if workflow must continue.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Staff reported the Branson Bransonic CPXH ultrasonic cleaner displayed a temperature alarm during heated operation."
Cause
What was observed during troubleshooting.
Example:
"Verified correct outlet and solution level, but alarm returned during controlled heat test with measured bath temperature above expected range."
Resolution
What action was taken.
Example:
"Removed unit from service, labeled Out of Service, documented temperature readings, and sent for bench evaluation of heater control and temperature sensing circuit."
Helpful Details to Include (If Known)
- Temperature setpoint
- Displayed bath temperature
- External thermometer reading
- Alarm message or indicator behavior
- Whether heat indicator was active
- Solution level checked
- Solution replaced
- Basket or load placement checked
- Outlet tested
- Cord and plug inspected
- Any unusual smell, heat, steam, or discoloration
- Whether alarm occurred at startup or during heating
- Final device status
Final Thought
Temperature complaints on heated ultrasonic cleaners should be approached carefully because they involve both cleaning performance and user safety. Start with simple external causes such as setpoint, solution level, load placement, and power condition before suspecting internal failure. If the unit cannot safely control temperature or repeats an alarm under controlled testing, remove it from service and document the findings clearly.
That is successful troubleshooting.