Skip to main content

This guide has more recent changes. Switch to the latest unverified version.

Steam Iron - Step 2: How does it work?

Video Overview

  1. Steam Iron - Step 2: How does it work?, General operating principle: step 1, image 1 of 3 Steam Iron - Step 2: How does it work?, General operating principle: step 1, image 2 of 3 Steam Iron - Step 2: How does it work?, General operating principle: step 1, image 3 of 3
    • When the Start button is pressed (item 1), a circuit is closed which powers, via a relay (item 2), the heating resistor placed in the soleplate of the iron (item 6). When the temperature is reached, a beep is heard (after about 2 minutes)

    • After the beep, steam can be produced by pressing the button in the iron's handle (figure 5) Thus, a circuit is closed which turns on a pump placed in the frame beneath the water tank (figure 3) This pump, placed between the tank (figure 4) and the iron will make the water flow from one to the other

    • The water, being carried into the iron's soleplate through soft tubing, will turn to steam when coming into contact with the heating resistor. Indeed, because of the heat (around 130°C-160°C), the water turns to steam and escapes through the holes in the sole. By releasing the button, the pump stops and so does the steam.

  2. Steam Iron - Step 2: How does it work?, Water pump operation: step 2, image 1 of 3 Steam Iron - Step 2: How does it work?, Water pump operation: step 2, image 2 of 3 Steam Iron - Step 2: How does it work?, Water pump operation: step 2, image 3 of 3
    • The device is made of several smaller bodies that we will look at seperately. We shall start with the water pump.

    • This kind of pump, called a suction pump, is frequently found in devices requiring the pressurizing of liquids, usually water. They can be found in expresso coffee machines (pressurized hot water for percolation), and certain steam irons.

    • The axial movement of a metallic piston (Fig. A), perforated at both ends so as to create the movement of the water, creates the pressure in the system. The back and forth is driven by a magnetic field created by a reel. You can see these parts by following the link at the end of this step.

    • The reel contains a diode in series with the coiling, which allows power from a single-phase, full-wave rectified voltage. Put simply, the piston follows the electrical current (50hz) and oscillates with 25 backs and 25 forths per second.

    • This very pronounced vibration is the source of the very recognizable sound of a functioning pump.

    • Water arrives on one side of the pump (yellow arrow on the schematic) goes through the actuator (Fig. A), and arrives in the pale pink chamber. This chamber is alternatively closed of by two valves, pink (Fig. B) and blue (Fig. C) The pink one lets the water into the chamber when the piston is released, and the blue one is closed.

    • When the piston is driven, the pink valve closes, the chamber is pressurized, forcing the blue valve open and letting the water through. This cycle is renewed 25 times per second.

    • Animation showing the pump in operation.

  3. Steam Iron - Step 2: How does it work?, Electronic Circuit Operation: step 3, image 1 of 3 Steam Iron - Step 2: How does it work?, Electronic Circuit Operation: step 3, image 2 of 3 Steam Iron - Step 2: How does it work?, Electronic Circuit Operation: step 3, image 3 of 3
    • The device is equipped with a printed circuit board located in the base of the tank. The operation of the device is entrusted to a microcontroller (Fig. 15). This manages the inputs-outputs of the device connected to the various elements, probe, sensor, pump and control panel in order to ensure proper heating of the iron.

    • Iron soleplate temperature management. It is carried out by means of a probe placed in contact with the soleplate. This iron does not have a manual thermostat to adjust the temperature of the iron. The temp is fixed and is controlled by the probe (see next step in Fig. 8) The temp measured on the soleplate of the iron is 160°C.

    • Pump flow management using a BT168 GW thyristor (Fig. 16) This allows the volume of steam to be reduced in ECO mode or increased in TURBO mode.

    • Iron inclination management. This iron has a tilt or motion sensor (Fig. 12) This takes the form of a capsule containing a metal ball. When the iron is horizontal, the ball closes the circuit: allowing the resistor to heat up. When the iron is tilted (on its base, for example), the circuit is open, and the resistor is no longer powered.

    • Descaling management By pressing the descale button, the pump operates for 2 minutes without interruption with the maximum flow rate. The iron will signal whenever descaling is needed. The micro-controller is programmed to manage this alert and will stop the pump if the operation is not started.

    • Light and sound signal management. 3 LEDs are placed on the printed circuit opposite each button of the control panel as well as a buzzer. The signals emitted by these components are described in step 3 of the "different functions" tutorial. Another led (Fig. 14) is connected to a small PCB board placed in the handle of the iron.

    • This small PCB board also supports the steam switch (Fig. 13) which is activated by the steam button (Fig. 5) and the tilt sensor (Fig. 12).

  4. Steam Iron - Step 2: How does it work?, Electric circuit operation: step 4, image 1 of 3 Steam Iron - Step 2: How does it work?, Electric circuit operation: step 4, image 2 of 3 Steam Iron - Step 2: How does it work?, Electric circuit operation: step 4, image 3 of 3
    • The electrical circuit is made up of a power cord with 3 conductors Phase (brown), Neutral (blue), Ground (green/yellow). These three wires are connected to the electronic board. The ground wire is extended towards the iron through a protective sheath.

    • In this sheath are also the wires that will supply the heating resistor (Fig. 11) via the Klixon protection (Fig. 9) and the temperature sensor (Fig. 8) as well as the control wires (M/A button, led. ..) which is in the handle of the iron. There is also the pipe in which the water circulates (Fig 10).

    • The attached diagram shows the main elements and their connections.

  5. Steam Iron - Step 2: How does it work?, Hydraulic circuit operation: step 5, image 1 of 1
    • The water circuit is as follows (red): the water is stored in the reservoir (Fig. 4) When the user requests steam by pressing the button placed in the handle of the iron (Fig. 5), the pump (Fig 3) is started. The water is then sucked up and sent through the tube (Fig. 10) to the sole of the iron (Fig. 6).

    • A safety bypass is located at the outlet of the pump (Fig. 17) If the water cannot be evacuated (clogged pipe) it returns to the tank (green).

Conclusion

Now that we know the functionalities of our device and we know the sub-assemblies and the operation, we can move on to the repair phase with the following tutorial: "Steam iron, Step 3: common breakdowns" (Please note that this page is currently untranslated.)

15 other people completed this guide.

Special thanks to these translators:

fr en

100%

These translators are helping us fix the world! Want to contribute?
Start translating ›

Atelier Soudé

Member since: 12/13/18

3,355 Reputation

15 Guides authored

Team

Atelier Soudé Member of Atelier Soudé

Repair Café

5 Members

27 Guides authored

3 Comments

Thank you for this guide, identifying the components was helpful. If there are some links for troubleshooting the pump system you would recommend, I would appreciate it as well. Let's make things repairable :)

civilizati3 - Reply

Thank you for this guide, identifying the components was helpful.

Same problem happened with me also. Pump of my iron is not working and it is very difficult to find the same in India. If there are some links for troubleshooting the pump system you would recommend, I would appreciate it as well. Let's make things repairable :)

Satnam Singh - Reply

Does your pump run when you press the calc button?

TheNightOwl -

Add Comment

View Statistics:

Past 24 Hours: 27

Past 7 Days: 143

Past 30 Days: 487

All Time: 15,389