Error F7 in a Haier washing machine

Even the most modern and expensive household appliances can fail during heavy use. A sudden F7 error in a Haier washing machine alerts the user to a motor failure. In this case, the problem may be a broken motor circuit, a damaged triac, a faulty winding, or worn brushes. To accurately identify the problem, you'll need to partially disassemble your "home assistant" and diagnose the various motor components. We'll examine each step of this lengthy process in detail.

We remove, inspect and test the engine

The F7 error code is quite common, so the steps to take when it occurs are well known. You can fix this problem yourself by following our detailed instructions, so there's no need to immediately call a service center technician. This manual is only suitable for machines with brushed motors, as machines with inverter motors are disassembled and tested differently. The first step is to gain free access to the electric motor. What do you do to achieve this?

• Unscrew the screws securing the rear panel of the washing machine, and then remove the wall itself.
• Disconnect all wires connected to the engine.

It's a good idea to take a few photos before disconnecting the wiring—that way, you'll have examples of how to properly connect the unit, which will come in handy during reassembly.

• Remove the bolts holding the motor in place and then remove it from the CM housing.

Now you can begin testing the unit. First, connect the stator and rotor winding wires, then apply 220 volts. If the rotor starts to spin, the electric motor is working properly. This is an extremely simple diagnostic method, but it does have its drawbacks.

• This test cannot fully test the motor's performance, as it will not determine how it will perform in different washing programs.
• This test can damage the motor when connected directly to the power supply. To reduce the risk of short-circuiting the motor, add a ballast to the wiring diagram, such as a washing machine's water heater element. In the event of a short-circuit, the ballast will heat up, thus protecting the motor.

The next step is to inspect the motor brushes, mounted on the sides of the element housing. These parts are made of a material that isn't particularly wear-resistant, so they wear out over time. The problem lies with the brushes if the motor starts to spark heavily when connecting the motor wiring to the power supply. In this case, repair is simple—just replace the brushes. Take the faulty brushes to the store as an example, or write down the model number so the salesperson can select suitable replacement parts.

Error code F7 can also be caused by the fins. These components are responsible for transmitting electrical current through the brushes to the rotor, so the error may be caused by detached fins. This can be corrected on a standard lathe by turning the parts to remove all surface defects. Be sure to remove all shavings to avoid clogging the "home helper."

We will check the control board at our own risk.

What should you do if the motor test reveals nothing, as it's fully functional? In this case, there's only one option: a faulty control module, the "brain" of your Haier washing machine. Repairing it without the necessary experience, knowledge, and equipment is almost impossible, but you can check it at home without calling a repairman. For inspection you will need:

• disconnect the washing machine from all utilities;
• remove the powder receptacle by pulling it towards you while pressing the central latch;
• remove the bolts holding the machine control panel;
• Using a small screwdriver, release the latches that hold the panel in place;
• Remove the panel and carefully place it on the lid of the washing machine so as not to break the wiring.

The control module is located just behind the control panel. Don't rush to disconnect all the wires from it—as before, it's best to take a photo of the correct connections first. Disconnect the wiring and remove the control board, first releasing the housing latches.

Now the module should be carefully inspected for damage. This could include dents, burnt areas, or any other damage. If you find any visible defects on the unit, it will need repair before you can continue using the "home assistant." Individual parts of the control board can be repaired yourself. For repairs, you'll need a soldering iron, a multimeter, and replacement parts.

If you're confident in your abilities, you can begin repair work. Be sure to familiarize yourself with the semiconductor components on the board that need to be checked.

• Capacitor. This component is the stabilizer on the board. If it is damaged, you need to solder a new element to the positive electrode, after first checking the electrode's polarity with a multimeter.
• Resistor. First, check the resistor with a multimeter. If it's a first-order resistor, the tester should ideally show a resistance of 8 ohms and 2 amperes of overload. If it's a second-order resistor, the tester should show 3-5 amperes, and the resistance will depend on the module's frequency. If you find a discrepancy, you'll need to solder the resistor.
• Thyristor unit. To test, measure the switch resistance; it should be no more than 20 V.
• Block filter. If it burns out, then you need to clean the cathode.
• Trigger. Check the voltage at the input contacts, which should be no more than 12 V, and then evaluate the trigger filter resistance, which should normally be 20 ohms. You'll also need to solder this part to replace it.

Most often, the washing machine's control module fails due to strong vibrations during the spin cycle, or due to sudden power surges. Always install household appliances correctly to ensure they are stable and level, and don't forget to install a surge protector. If you are unable to resolve the F7 error code yourself, call a service center specialist to restore the machine's functionality.

   

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