Fresenius 4008B
Fresenius · Model 4008B
Through continuous optimization of the treatment modalities Fresenius Medical Care always aims to offer patients the best renal replacement therapy to Our hemodialysis system 4008S guarantees safety and efficiency of all important treatment modalities within the scope of renal replacement therapies, such as Bicarbonate or acetate dialysis, Single-Needle or single-needle click-clack, Ultrafiltration and sodium profiles, Isolated ultrafiltration / Bergström treatment, Online-Hemo(dia)filtration. The hemodialysis equipment can be adapted by the modular combination of extensive options to special therapy modalities. The automated acquisition, monitoring and control of specific patient and machine parameters provide the operator with continuous and precise assessment of the current treatment situation. The 4008S machine is available with 5 functional slots for slide-in modules.
Key tips
- ·Conductivity and water-quality checks are non-negotiable before every shift - dialysate chemistry errors are a direct patient-harm mechanism.
- ·Confirm disinfection cycle completion, never assume it, after every use.
- ·Treat a blood-leak detector fault as real until proven otherwise - never silence and continue.
Typical Failure Modes
Compiled for this model from its own documentation and established engineering knowledge for this equipment class - not from a verified service record. Confirm against the manufacturer's service manual.
Conductivity / temperature / dialysate-prep alarm
HighSymptoms: Conductivity or temperature out of range, dialysate-preparation alarm, treatment will not start.
Root cause: Concentrate connection / supply, a heater fault, a conductivity-cell fault, or a proportioning-pump / valve fault.
Blood or dialysate pump fault
MediumSymptoms: Pump will not run at set speed, occlusion or flow alarms, tubing walking in the raceway.
Root cause: Worn pump rotor / rollers or a motor / control fault.
Pressure-monitoring / air-detector fault
MediumSymptoms: Venous / arterial / TMP pressure implausible, air-detector false alarms or fails to detect.
Root cause: Transducer-protector wetting, a pressure-sensor fault, or an air-detector fault.
UF / balancing-chamber fault
MediumSymptoms: Fluid-balance / UF alarms, weight loss inaccurate, balancing-chamber leak.
Root cause: Balancing-chamber diaphragm / valve wear or a flow-sensor fault.
Disinfection / rinse fault
MediumSymptoms: Heat or chemical disinfection will not complete, residual disinfectant test fails.
Root cause: Heater, a dosing / rinse valve, or a conductivity-verification fault.
Serviceable Parts & Consumables
Serviceable items for this model, compiled from its documentation and engineering knowledge for this equipment class. Service class and relative cost are estimates, not manufacturer figures; no part numbers are given. Confirm intervals and pricing against the manufacturer.
Blood / dialysate pump rotor & rollers
Class Periodic replacementRel. cost $$R&R Moderate
Conductivity cell / temperature sensor
Class Periodic replacementRel. cost $$R&R Moderate
Pressure sensors / transducer protectors
Class Periodic replacementRel. cost $$R&R Fairly easy
Balancing-chamber diaphragm / valve kit
Class Periodic replacementRel. cost $$$R&R Difficult
Proportioning pump / valves
Class Major service partRel. cost $$$R&R Difficult
| Part | Service class | Relative cost | R&R difficulty |
|---|---|---|---|
| Blood / dialysate pump rotor & rollers | Periodic replacement | $$ | Moderate |
| Conductivity cell / temperature sensor | Periodic replacement | $$ | Moderate |
| Pressure sensors / transducer protectors | Periodic replacement | $$ | Fairly easy |
| Balancing-chamber diaphragm / valve kit | Periodic replacement | $$$ | Difficult |
| Proportioning pump / valves | Major service part | $$$ | Difficult |
Relative cost: $ lowest · $$$$ highest service-part cost for this equipment class. Not a price.
PM Checklist
Preventive-maintenance tasks typical of this equipment class. Perform to the manufacturer's procedure and your facility's policy - this is general reference, not a schedule for this specific unit.
- ·Disinfection cycle verification
- ·Conductivity and water-quality check
- ·Blood-leak detector test
- ·Scheduled tubing / filter replacement
- ·Annual full PM
Error Codes
Extracted directly from this unit's own service manual.
F01 HPUPresent options and DIP switch settings do not match. CPU1 system status (MST), HPU status and DIP switch/Array2 changed during the test running time. – ONLINE plus: CPU 2: Array 2, DipSw2 not set to OFF CPU 2: Array 2, DipSw3 not set to ON – DIASAFE plus: CPU 2: Array 2, DipSw2 not set to OFF CPU 2: Array 2, DipSw3 not set to OFF – MST transmitted by CPU1 not matching with the set DIP switch of array 2. – DIP switch/Array2 changed while the test was in progress. – HPU logged off. F34 ONLINE plus F34 DIASAFE plus Pressure holding test not passed. Max. number of treatments exceed- ed? –
F02 HPUDialysate outlet pressure (DA1) outside the permissible range (10s). DA1 test range: –125mmHg ≤ P_dial ≤ 55 mmHg – Acknowledgement DA 1 (P_DIAL, X633L/B6) → X632/A29 – Acknowledgement line DA 2 (see HPU diagram) F03 ONLINE plus F03 DIASAFE plus
F03 HPUCross comparison of both pressure transducers (DA1 / DA2) is outside the acceptable tolerance (10s). P(DA2) == P(DA1) ±20mmHg – Acknowledgement DA 1 (P_DIAL, X633L/B6) → X632/A29 – Acknowledgement DA 2 (see HPU diagram) F41 ONLINE plus F41 DIASAFE plus
F41 HPUThe test valve V183 is leaking. Pressure increase in the system of ΔP(DA2) > 30 mmHg within 4s. – V183 open, contaminated, or mechanically defective – HPU, output stage etc. defective F42 ONLINE plus F42 DIASAFE plus
F42 HPUNo pressure increase of ΔP(DA2) > 200 mmHg within 4s after opening the test valve V183 in the system. – V183 fails to open or mechanically defective. – Air pump defective, is not running – HPU, V183 and/or air pump output stage etc. defective Fresenius Medical Care 4008 5/03.09 (TM) 1-49 F43 ONLINE plus F43 DIASAFE plus
F43 HPUThe lower pressure test range of ΔP(DA2) > 300 mmHg failed to be achieved within 1s after closing the test valve V183. – HPU, output stage etc. defective – ONLINE filter leaking F44 ONLINE plus F44 DIASAFE plus
F44 HPUThe upper pressure test range of ΔP(DA2) 750 mmHg was exceeded within 4s after closing of the test valve V183. – HPU, output stage etc. defective F04 ONLINE plus F04 DIASAFE plus The air pump is running although valve V43 is closed. – HPU, output stage etc. defective F05 ONLINE plus The door on the Online Sys module is open during the rate test. – Close module door. F06 ONLINE plus Port 1 is open during the first pressure build-up phase. – Close port 1 (substituate port). F07 ONLINE plus Port 2 is open during the first pressure build-up phase. – Close port 2 (rinse port). F08 ONLINE p
F11The interval between the strokes of the UF2 pump was less than 220 ms. Correct delivery of the required volume is not safeguarded because the stroke return travel is too short. – A pump rate which was too high was signalled by the CPU 1.
F12The pulse time for the UF2 pump is less than 180 ms. Correct delivery of the required volume is not safeguarded because the discharge time is too short. – Monoflop on LP 634 defect (IC 42/R65/C45).
F13The pulse for the UF2 pump is longer than 500 ms. A maximum rate of 5000 ml/h is not possible. – Monoflop on LP 634 defect (IC 42/R65/C45).
F14UF2 pump not active during the test (4 s). – Acknowledgement (UF_P2, X637/B26) → X632/C7 no LOW pulse – Control line (UF_P2, X634L/A–C24) → X637/B26 no LOW pulse
F15The UF2 pump cannot be stopped by the CPU2. – Control line (UF_P_EN, X632/C28) → X634R/A22 no 5 V. – Reset input to IC 42/pin 13 on LP 634 defect.
F16The UF pump acknowledgement from CPU1 is faulty. – Acknowledgement (UF_P2, X637/B26) → X633/C23 no LOW pulse
F17The change in pressure after a UF2 pump stroke less than 20 mmHg. – UF2 pump mechanically defect. – Control line (UF_P2_CRTL, X632/B24) → X634R/C11 no HIGH pulse.
F20Difference in pressure between UF pump stroke and UF2 pump stroke more than 20 %. – Stroke rate for UF pump or UF2 pump not set correctly.
F326UF1 volume-Error or UF2 volume-Error
F327UF-failure
F328UF-failure
F329UF-failure
F330UF-failure
F331UF-failure
F332UF-failure
F333UF-failure
F334UF-failure
F335UF-failure
F336UF-failure
F337UF-failure
F338UF-failure
F339UF-failure
F340UF-failure
F341UF-failure
F342UF-failure
F343UF-failure
F344HDF-failure
F345HDF-failure
F346HDF-failure
F348HDF-failure
F349HDF-failure
E.01Line diameter outside the permitted range
E.02Non-defined hexaswitch position
E.03Venous pressure transducer not balanced
E.04Failure, running time monitoring system, SN operation
E.05SN stroke volume outside the permitted range
E.06The SN pressure thresholds outside the value range of the AD converter
E.07Not defined
E.08Failure in the AD conversion
E.09Not defined
E.10Not defined
E.11Not defined
E.12Failure, speed monitoring (hall sensor)
E.13Failure, monitoring system, current sensing resistors
E.14Failure, monitoring system, current sensing resistors
E.15Failure, speed monitoring system
Troubleshooting Approach
A starting sequence for this model, compiled from its documentation and engineering knowledge for this equipment class. Follow the manufacturer's service documentation for the actual procedure.
Symptom: Conductivity / temperature / dialysate-prep alarm / treatment will not start
- Confirm the concentrate is connected, correct and not empty.
- Verify dialysate conductivity and temperature with independent calibrated meters.
- Check / calibrate the conductivity cell and temperature sensor.
- Inspect the proportioning pumps / valves and de-air the hydraulics.
- Do not treat until conductivity and temperature are verified in range.
Symptom: Blood or dialysate pump fault / occlusion or flow alarm
- Inspect the pump rotor and rollers for wear and correct the occlusion setting.
- Reseat the tubing segment in the raceway.
- Check the pressure transducers and their protectors for wetting.
- Calibrate the pressure channels.
- Replace the rotor / rollers or a faulty sensor as isolated.
Symptom: Pressure / air-detector / blood-leak alarm implausible or not triggering
- Verify each pressure channel against a reference.
- Test the air detector and the blood-leak detector per the service procedure.
- Clean the blood-leak detector optics.
- Calibrate the channels.
- Replace a sensor that fails its functional test - these are safety systems.
Symptom: UF / balancing-chamber fault / disinfection will not complete
- Check the balancing-chamber diaphragm / valves and the flow sensors.
- Run the UF calibration.
- For disinfection, check the heater, the dosing / rinse valves and the residual test.
- Replace the balancing-chamber kit as isolated.
- Verify fluid balance and a clean residual test before clinical use.
Typical Location
Where this class of equipment is typically deployed - general reference, not this unit's own placement record.
- Dialysis unit / clinic
- ICU (acute dialysis)
- Home hemodialysis
Documents & Manuals
- Fresenius 4008 HDR Tech ManualDocument · External
- Fresenius 4008 Series Technical ManualDocument · External
- Fresenius 4008B Device AlertDocument · External
- Fresenius 4008B Hemodialysis Technical manualDocument · External
- Fresenius 4008B Tech TrainingDocument · External
- 4008 Series Technical ManualDocument · External
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