This page lists the most common problems that can occur when using the device. If your issue isn't listed here or you have further questions, feel free to contact Zeitz-Instruments. We will answer your messages as quickly as possible.


ATTENTION: Please read the PRECAUTIONS first, before attempting any repairs!

The puller makes a very loud noise, when moving the filament in or out

The spindle that moves the heater (Fig. 5, 1) needs greasing. You will find the spindle by opening the right-hand cover to which the acrylic glass cover is attached (Fig. 1, 14). The grease for the spindle is located in the box supplied with the puller, although any machine grease is suitable.

  • Spread the grease over the spindle in front of and behind the rectangular brass piece (Fig. 5, 5). To spread the grease behind, make a few turns on the spindle with a screwdriver. After that turn the spindle with the screwdriver to about the heater's middle-position, close the cover (tighten it with all four screws) and switch on the puller. The heater will then retract into its resting position.
  • Should the noise reoccur after a short period, please inform Zeitz-Instruments. We will send another brass piece.

The heating clamps produce sparks / The filament breaks early
The filament and especially the clamps are corroded over time due to too weak tightening which caused an isolating black stain. To fix this remove the black stain from all contact points of the clamps (removable sleeves as well as fixed parts) and from the filament using fine emery paper. When installing the filament again, be sure to tighten the screws well. For the lower clamp use the hex-key to tighten the knurled screw by another 60-90 degrees. Tightening just by hand is not enough!

A glass clamp won't open again

There are three possibilities:

  • The fuse has burnt out: You will find the fuse when you open the big cover in which the keyboard is integrated. The fuse is located right on the middle board of the three big boards in the upper region. There are two fuses, one each for the right- and left-hand motors. The fuses are round and normally black or brown. They have a diameter of about 8 mm and are rated at 500 mA (should be visible on the fuse). Next to the fuses there are located the connectors and the wires that lead directly to the motors, so you can find easier the fuses. The fuses can be pulled out from the socket. If the fuse has been burnt out, replace it with a fuse from the set in the spare-parts box supplied with the puller. Provisionally you can replace it with a common, commercially available fuse (500 mA).
  • There is a mechanical blockade in the holder. If this appears to be the case, try to move the brass element by turning the small screw with a screwdriver. The puller should be switched off for this attempt. When the brass element is in the front position, turn the screw (spindle) counter-clockwise to free the block. When the brass element is in the rear position, turn it clockwise to free the block.
  • The gear is broken. Contact Zeitz-Instruments. We will send a new holder.

The glass tube does not appear to be vertically centered inside the filament

There is a screw mounted right on the bottom of the heater tower (Fig. 5, 3). The centring can be adjusted by turning this screw slightly:

  1. Insert a glass blank in the glass holder.
  2. When the glass has clamped and the heater comes out, switch off the puller by MAINS, disconnect the power cord from the socket.
  3. Open the lower right-hand cover.
  4. Loosen the screw mounted on the bottom of the heater tower slightly. Lift the heater tower slightly and observe the position of the glass in the heater filament, ensure that it is centred in the middle position of the filament.
  5. Tighten the screw and close the cover.
  6. Switch on the puller. The heater moves back. Press the BREAK button so the puller releases the glass.

Electrodes do not seperate

The puller’s reproducibility derives basically from the settings and characteristics of the heater, including shape, position, age and minor, unavoidable variations in the installation. Whilst in our puller these problems are compensated for mostly by the initial pull, which indicates when the glass has melted, this compensation is not complete. Since the pulling rod has been cleaned and the heating filament renewed without the problems being resolved (error messages still displayed e.g. the BREAK light), following remedies are suggested:

  • Reduce the time delay P(B) t(F1) a little (about 5 points)
  • Alternatively raise the strength of pull F2 (about 20 points). Since the F2 light is illuminated, the puller has reached the endpoint of pull F2, but this pull is apparently not strong enough.
  • A further alternative is increase pull F1 (also about 20 points), so that the velocity of the pulling rod is somewhat higher when pull F2 is turned on.

The glass clamp does not open automatically

You have initiated the polish mode. To switch off the polish mode press P(B). Press AD, insert 000 and press ENTER.

Electrodes are asymmetric

A mechanical problem is indeed possible.

  • Check the alignment by clamping a piece of glass in the left-hand holder and one in the right-hand holder, so that the ends of the glass pieces touch each other at the position where the heater appears. The two pieces of glass should form a straight line from the left-hand end of the left-hand glass to the right-hand end of the right-hand glass.
  • Should this not be the case please contact Zeitz-Instruments.

To avoid the right-hand glass holder releasing the glass while the glass is being mounted in the left hand holder (or vice versa), pull out the connector on the rear big middle board with the twin blue/white cable leading to the right-hand glass clamp motor. Conversely, pull out the connector with the twin red/white cable to prevent the left-hand glass holder releasing its glass. Hold the glasses by hand straight in the holder while pressing START. TAKE CARE not to burn your fingers when the heater appears!!!!

To adjust, loosen the small front plate of the right-hand holder by loosening the two screws a little and adjust the position of the front plate a little. Then retighten the screws.

Temperature needs to be increased very periodically to reproduce pipettes

The filament must be renewed. Tighten the knurled screw (Fig. 5, 3) using a little wrench (be careful not to break the screw, but also to tighten it sufficient)

Pulling is very slow / Excessive friction inside the pulling mechanism

Rough handling during transport has possibly misaligned the pulling rod (Fig. 1, 16), causing excessive friction, or caused a wire to tangle with the pulling rod. To test the friction:

  1. Switch off the puller (MAINS).
  2. Pull the pulling rod (the left pull arm) out to the right as if it were in its ready position.
  3. Then lift the right hand end of the puller about 15 cm leaving the left-hand end on the bench.

The pulling rod should run back by itself (under gravity) the whole way. If not, then the pulling rod is misaligned or some wire is holding it.

  1. Open the front left-hand cover (Fig. 1, 13) and open the upper cover in which the keypad is integrated.
  2. See if a wire is preventing the movement of the pulling rod.
  3. If not, move the pulling rod by hand and listen if friction is preventing the pulling rod from moving.

The pulling rod and its carriage is hold and fixed by six screws, four behind the pulling rod and two in front (Fig. 2, 2). Adjustment, realigning and fixing is complicated, requires patience and should be attempted only when it is certain the pulling arm is misaligned (Be careful not to damage the aluminium cup (Fig. 2, 3) or not to touch the glasspane (Fig. 2, 6) attached to the pulling rod!). If this is not successful, return the puller to Zeitz-Instruments.

The glass clamps do not open wide enough or are closed

Should the glass holders be closed when attempting to insert a blank try the following:

  1. Press READY and then BREAK.
  2. Wait a few seconds.
  3. Press READY again.
  4. The glass holders should now be completely open. If not, repeat the procedure.
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