The recent steam sterilizers used in clinics, ophthalmology and dental cabinets are fully-automated, microprocessor-controlled.
Controlled parameters are constantly monitored by the internal CPU to assure proper sterilization for each program (cycle selected).

How To Fix The Alarm A258 In Millennium Series

Every time an anomalous condition occurs during the operation of the sterilizer, an alarm is generated, identified by a specific code (consisting of a letter followed by a 3-digit number).
Alarm codes are divided into three categories:
• E = ERROR
Wrong manoeuvre and/or use, or a cause external to the device.
A problem that can generally be fixed by the user.
Code format: Exxx (xxx = identifying number 000 ÷ 999)
• A = ALARM
First-level fault, not linked to safety.
A problem that normally is fixed by a specialized technician on-site.
Code format: Axxx (xxx = identifying number 000 ÷ 999)
• H = HAZARD
Second-level fault, linked to safety.
A problem generally fixed by the Technical Support Center.
Code format: Hxxx (xxx = identifying number 000 ÷ 999

Alarm during a cycle
If the alarm intervenes during a program, the display will show the message:
( A l a r m M e s s a g e )
L E V E L L I N G . . .
1 1 4 . 6 ° C X X X X
0 . 7 0 b a r 1 1 : 3 0
Whenever an alarm is generated in certain phases of the cycle, an automatic procedure is activated to clean the internal water circuit. The display
will contain the notice:
( A l a r m M e s s a g e )
C I R C U I T C L E A N I N G
1 0 0 . 6 ° C X X X X
0 . 7 0 b a r 1 1 : 4 0
At the end of what has been described and having reached safe conditions, the machine activates a special procedure, that asks the user to
manually unlock the door:
P R E S S T O
U N L O C K T H E D O O R
1 0 1 . 0 ° C X X X X
0 . 0 1 b a r 1 1 : 4 0
Press the key to unlock the door lock mechanism; the following message appears:
( A l a r m M e s s a g e )
O P E N T H E D O O R
1 0 0 . 8 ° C X X X X
0 . 0 1 b a r 1 1 : 4 2

What this means A258 ?

The lcd shows PPP TIMEOUT

Pressure rise not performed
within 7’ timeout
Pressure rise (from
0.00 to +1.12/2.15 bar)
not performed within
the preset time

Possible cause / Check Proposed solution
1*/Sterilization chamber overloaded
Advice the operator for properly loading of the sterilization
chamber
Restore the safety thermostat and repeat the sterilization
cycle.
2*/Intervention of the steam generator safety
thermostat
Replace the safety thermostat
3*/Steam leakage from the door gasket
Clean properly the gasket and the parabola board
Replace the door gasket
4*/Steam leakage from a valve
Identify the valve and clean it
Replace the valve causing the problem
5*/Steam leakage from a pipe
Replace the pipe causing the problem
6*/Steam generator clogged
Replace the lower section of the steam generator
Different distilled water must be used
7*/Fault in the board
Replace the CPU board
CPU board uncalibrated
8*/Check the continuity of the steam generator cartridge
Replace the failed cartridge.

I’ll focus on the steam generator, because in most cases this unit is clogged because the operator uses inadequate water , absence or lack of regular maintenance.
Here is the step by step how to proceed:

How To Fix The Alarm A258 In Millennium Series
Before servicing, switch off the equipment and unplug the power supply cable from the mains socket
1. Remove the covers
2. Empty both reservoirs;
3. Remove the water pump assembly
4. Disconnect the PT2 and cartridge resistor wires from the electronic boards;
5. Turn the equipment on a side, remove the plate under the chassis in order to access the steam generator;
6. Unlock the clips on the thermal insulation panel of the chamber and access to the screws fixing the heating bands; remove the screws of the heating bands
and move out the steam generator in order to disconnect the pipes;

Fixing The Alarm A258 In Millennium Series7. Remove the screws of the thermal insulation panel (1) on the steam
generator;
8. Loosen the screws and remove the thermostat probe (2). Remove the probe
PT2 (3); loosen the screws and remove the cartridge resistors (4);
repair The Alarm A258 In Millennium Series

servicing The Alarm A258 In Millennium Series

9. Remove the screws fixing the steam generator sections and clean the
surface (6)

troubleshooting The Alarm A258 In Millennium Series

checking The Alarm A258 In Millennium Series

Run a sterilization cycle
10. Replace the bottom section, mount a new O-Ring (7) between the sections
and assembly all items and restore connections proceeding in reverse order
as above;
11. Run a sterilization cycle.

 

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About

Bougrine-Professional Electronic Repairer From Morocco field:Dental Chairs & Stools , handpieces , micromotors etc.. dental supply equipments: Sterilizers,

One comment on “How To Fix The Alarm A258 In Millennium Series

  1. Daud Asi says:

    Although it is not related to our field but efforts are much appreciated.

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