How the UBL of a washing machine works?

You probably don’t give the numerous parts that keep your washing machine operating smoothly a second thought when you start a load of laundry. The UBL, or door lock mechanism, is an essential component that is necessary to guarantee both your safety and the machine’s correct operation.

During a wash cycle, the UBL is in charge of locking the door firmly to keep it from opening by accident. This device shields you from possible dangers in addition to preventing water from spilling out. Gaining an understanding of the UBL’s functionality can aid in troubleshooting and guarantee the continued safe operation of your washing machine.

We’ll examine the inner workings of the UBL in this post, explaining its function during washing and the reasons it’s crucial to the overall functionality of your appliance.

What types of locking devices are there and how they work?

After deciding to handle the issue on your own, you must understand how the UBL operates and what locks are fitted in automatic machines. Manufacturers have fitted washing machines with bimetallic plate mechanisms or electromagnetic locks over the past few decades.

Electromagnetic devices are regarded as highly unreliable. These locks only prevent the hatch from opening when power is applied. The mechanism will stop operating right away if the apartment’s power is abruptly cut off. The great majority of contemporary washing machines have UBL based on bimetallic plates.

Blockers with bimetallic plates work on a very basic principle. Three elements guarantee the mechanism’s operation:

• thermal element;
• locking hook;
• bimetallic plate.

The UBL heating element receives voltage when the user begins to wash. The bimetallic plate receives heat from the heated part. The plate then grows larger due to the high temperatures and presses against the lock. The door is blocked as soon as the hook swiftly engages and shuts the mechanism. The hatch stays firmly shut even as the current "enters" the lock.

The heating element gradually cools down when the washing is finished and the voltage supply is cut off. The bimetallic plate retracts backward as it stops heating up and gets smaller. The washing machine hatch can then be opened with ease.

Wait two to five minutes after the cycle is over before opening the door because the bimetallic plate needs time to cool.

The locking device’s contact occasionally wears out. The plate doesn’t heat up, the lock doesn’t function, and the thermoelement stays cold in this scenario. The wash does not begin because the control module does not receive a signal regarding the tightness of the system.

The opposite circumstance occurs when the locking device continues to receive power even after the cycle has ended. The control module then locks the door and prevents the elements from cooling down. In this instance, the only way to access the drum is to turn off the machine’s power.

In order to prevent water leaks and unintentional opening, a washing machine’s UBL (Universal Bi-metal Lock) safety feature makes sure the door remains firmly locked during the wash cycle. The locking mechanism is activated by heating a bimetallic strip, which keeps the door closed until the cycle is finished and it is safe to open. This straightforward but essential mechanism protects the user and the machine by ensuring that your laundry is finished without interruption.

Faults indicating the UBL

How can I tell if the locking mechanism is broken? Sometimes you can identify a malfunction without even taking the "home assistant" apart. You will be notified of the malfunction by the machine itself. You should consider the possibility that the lock isn’t working properly if:

• the washing machine door remains locked even 2-3 hours after the program has finished;
• after starting the wash, the machine display shows an error code indicating problems with the UBL;
• attempts to start the wash are unsuccessful – the UBL cannot lock the hatch. In this case, the reason may be either in the lock or in the control module.

As soon as you notice even one of the "symptoms" listed, you should disassemble and inspect the locking mechanism. Let’s see if we can unscrew the washing machine’s body lock.

Dismantling the UBL for testing

Understanding how the UBL works, it will not be difficult to check the mechanism for operability at home. Diagnostics of the lock is performed with a multimeter. How to remove the lock from the body of an automatic machine? There are two options for action. The first is to remove the UBL through the front wall, removing the hatch cuff. The second is to pull the device out through the top of the machine, removing the housing cover. The last option is more suitable for beginners, because it is not so easy to put the sealing rubber back in place. If you do this task incorrectly, it is easy to break the tightness of the system. Then leaks will be ensured.

The hatch locking device is most easily accessed through the automatic machine’s top.

The following will be the sequence of events:

• de-energize the equipment;
• open the door of the washing machine completely;
• find the "key hole", it is located to the right of the hatch (this is a small "well" where the "tongue" of the door enters);
• unscrew the two bolts located next to the lock hole;
• remove a couple of screws securing the top panel of the case;
• remove the cover;
• slightly tilt the machine back, put your hand down along the front wall;
• feel the blocker and throw off its chip with wires;
• pull the UBL out.

You will now hold the blocker in your hands. It’s not always necessary to buy a new gadget right away because it might not be the issue. Use a multimeter to inspect the component as a result.

One important part of washing machines is the UBL (Unlocking Blocking Lock) system, which locks the door while the machine is in use to ensure safety. It keeps things from accidentally opening, which could cause damage and spills of water.

Gaining an understanding of the UBL’s operation can aid in washing machine troubleshooting. The UBL may be the reason why the door won’t lock or unlock properly, and being aware of its purpose will facilitate repairs.

You can feel secure knowing that your washing machine runs safely and effectively during every wash cycle if you maintain the UBL in good working order.

Video on the topic

How to check the UBL (Hatch Lock) of a washing machine!

The principle of operation of the hatch lock (UBL) of a washing machine, thermal, impulse

The principle of operation of the lock in a washing machine, or why the hatch is not locked in a washing machine