UBL washing machine repair

How does the UBL of a washing machine work? Without a hatch blocking device, washing in a front-loading unit is impossible: there will be a risk of accidentally opening the hatch, which will lead to flooding of everything around. But sometimes UBL leaves the hatch blocked even after the wash cycle has completed, which makes it impossible to empty the drum and continue to use the machine. Let's figure out whether it is possible to independently repair the UBL washing machine in order to still open the hatch door.

Let's figure out the reasons for the lock failure

There are three main reasons why the locking mechanism fails. The first is depreciation. Over time, the mechanism wears out as the bimetallic plate is constantly exposed to high temperatures and becomes thinner. The weaker the plate, the less reliable the fixation, which sooner or later leads to failure. In this case, the problem can only be solved by replacing the UBL.

The second reason is a problem with the electronic component of the model. There are two main options here:

The voltage in the network jumps, which is why the thermoelement “breaks through” and stops heating. As a result, the chain reaction to the plate and the clamp does not start;
closes the triac on the control board, which is responsible for supplying current to the locking mechanism. As a result, the current flow is not stopped and the blockage is not cleared.

The third type of reasons is mechanics. The tongue on the UBL lock sometimes breaks, interfering with the operation of the device. The hatch may also not open at all for reasons not related to the UBL. For example, the door hinges were deformed or something was sagging somewhere.

Important! To avoid problems of this kind, never allow children to ride on the door and do not hang wet laundry on it!

Diagnostics with a tester

Each washing machine must come with an electronic circuit. Before diagnosing the UBL, it is necessary to study the device. Find out the location of the phase, neutral contact, common contact and only then proceed to remove the locking device.

disconnect the washing machine from all communications;
open the hatch door;
unscrew the two UBL holder bolts on the right side of the hatch;
unscrew the bolts holding the top cover of the CM;
push the cover towards the back wall and remove it;
run your hand down to the right of the hatch door, feel for the UBL;
disconnect the wiring and remove the device.

Now take your multimeter and set it to measure resistance. Place one probe on the phase and the other on the neutral. If a number less than three digits appears on the multimeter screen, you can stop checking and change the UBL. If not, move on. Connect the empty wire to the common wire and to the phase. Using a screwdriver, move the locking device into the working position and connect to the network. The working device will click, but the faulty one will not.

Repairing the lock yourself

So, the hatch locking device itself is quite simple. In fact, there is almost nothing to break there. Therefore, the repair can be done quite easily with your own hands, if you are careful and do everything according to the instructions. So what do you need.

Disassemble the locking device. It consists of 3-4 metal parts and 2-3 plastic elements. It is not necessary to disassemble everything thoroughly, but you will need metal parts. In order to disassemble the UBL, you will need a small screwdriver.On one side of the device (plastic) there is a small screw or several screws that need to be removed. Once you do this, it will be easy to disassemble the device. If the metal parts do not give in, carefully pry them up with a screwdriver so as not to bend or deform anything.
Clean the metal parts so that they are free of oxidation, rust and dirt (the upper and lower bimetallic strips, the metal cylinder and the copper breaker itself with two contact points and a connector). The breaker can be identified by a small spring inside it.
Take the breaker in your hands and remove the spring from it. This is done without special devices, simply by pressing with your fingers.
Choose a spring of the same size, only tighter, so that it holds the lock better.
Place the breaker in place and secure it.

Now you can use a multimeter to “break through” the UBL contacts again. If the problem was truly in the device, stripping the metal parts should help restore the desired level of resistance. As for the spring, a more resilient new part will work better, preventing the locking device from "dangling". The steps described above can hardly be called a full-fledged repair, but sometimes they really help. If the problem is more serious, it is easier to buy a new lock.