If your Bosch washer shows an e27 error code, this indicates a malfunction of the pressure sensor. The detail is also called a pressure switch or a water level switch. If the pressure switch (level switch) fails, the device can stop in the middle of the cycle. It refuses to continue working. As a rule, if there is a breakdown of the sensor, the only solution is to replace it.
After changing the part, the e27 error code of Bosch washer will disappear. The element can’t be repaired, but what if the problem is not related to it?
Meaning and structure of the pressure switch
Since the main module controls the work of the washer’s parts, it does two functions. It has to give a signal to stop water draining, and also close the inlet valve. But how does the module know that the collected capacity is enough? The pressure switch controls the amount of water that enters the device. Each separate mode (washing or rinsing) requires a specific amount of water.
Pressostat is a plastic covered piece of a round form. A hose, which is under pressure, and wiring are connected to it. There is a thin membrane and switch inside the relay housing. The pressure in the tank depends on the amount of collected water. Air under pressure passes through the hose, it has an effect on the membrane, and it arches and closes the switch. With the help of wiring, the module receives a signal to stop the water intake.
Many users do not know where the pressure switch is installed in the washer. Some of them think that it locates inside the tank. In fact, the device is set up at the top of the washer case, near the sidewall.
Checking the pressure switch for serviceability
First, do the following steps:
- Observe general safety rules. Disconnect your washer from the mains by pulling the plug from the outlet.
- Tighten the inlet valve, which manages the water supply.
- To test the water level sensor, remove the top panel of the washer.
- After removing the screws, slide the cover forward.
- Leaving the panel aside, find the sensor.
Unscrew the bolts that hold it, slide the cover away from you and remove it. The sensor is mounted with 1-2 bolts, unscrew them, too. Also, it is necessary to detach contacts and a hose from the pressure switch. To do this, unscrew its clamp using pliers.
After that, check the sensor using a hose, which is about 10 centimeters in length. The diameter of the part should be the same as that the tube, removed from the pressure switch before. Put one end of this hose on the inlet fitting, and blow in the other side, applying the pressure switch to your ear. You should hear a few clicks (from one to three depending on your washer). It indicates the performance of the sensor. If there is silence inside the pressure switch, then it does not work.
Check the unit for damage. Check its hose for blockage. If there is clogging, clean the hole under the tap water pressure.
Having made sure that everything is okay, the last thing to check is the multimeter. Set the tester to resistance mode and connect the tester probes to the relay contacts. When the contacts are active, the figures must change. If they remain at the same level, the sensor is defective. To know which contacts to connect the tester, you need an electrical diagram of the device.
Pressure switch self-repair
Sometimes, you can make adjustments of the pressure switch in your washer. In this case, there is no need to replace the part. How to proceed:
- It is important to know how much water required for a washing machine model to run each program. Based on their number, the sensor is equipped with one to three screws.
- Following the required amount of water in the mode, it is necessary to tighten the screws.
Knowing how to adjust the pressure switch, you can avoid buying a new part. But it is not easy to calculate the correct change coordinates. The point is that only the specialists at the plant do such work.
Pressure switch replacement
First of all, you need:
- Disconnect all wires (take pictures or mark the connections if necessary).
- Unscrew the bolts that secure the device to the body.
- Disconnect the hose
To connect a new pressure switch, repeat all the steps in reverse order.
Next, you have to run the washer. Check if the new sensor is working and whether the e27 error code of the Bosch washer remains.