Window Sensor W2 – Wireless sensor for windows and balcony doors that turns off air conditioners (V2)

(25 customer reviews)

 36,00 (excl. VAT, if applicable)

Window Sensor W2 is the only wireless system on the market that can turn off the air conditioner when it senses that windows or balcony doors have been opened.

Its wireless technology means it can be fitted to air conditioners in use with no need for expensive masonry work, as no cabling is required for the W2 window and balcony door sensor to work.

Thanks to Window Sensor W2 you can turn off the air conditioner when there is no need to keep it on, and avoid wasting electricity and money.

Its technology can also handle shutdown of fan coil systems. With Window Sensor W2 from SaveOnAirCo, guests who leave the air conditioner running with the windows open will no longer be a problem!

Window Sensor W2 is the most economical solution on the market for saving money on air conditioning costs by turning off systems when it senses open balcony doors or open windows.

Compatible with any air conditioner and fan coils

The Window Sensor W2 sensor from SaveOnAirCo is simple to set up and use.
In as little as 5 minutes it is ready to monitor the opening of windows or balcony doors (or both).

Window Sensor W2’s strong points:
1. Turns off the air conditioner when a window or balcony door is opened.
2. Quick and easy to install.
3. Does not require masonry work.
4. Compatible with 100% of air conditioners.
5. Compatible with fan coil systems.

If the window is opened, AC will be turned off automatically!

Package Contents

1 Window Sensor W2 receiver switch (the part with the antenna, to be fitted on the split)
1 magnetic sensor (2 component parts) with adhesive tape included for easy attachment

SOME ADVICE: Window Sensor W2 can be used with our remote controls, and we recommend you do this. W2 can save money on bills when guests open the window or balcony door, preventing them from leaving the air conditioner on, while the remote control helps save money when the air conditioner is running by preventing guests from setting excessively low temperatures, which increase energy consumption and the money on your electricity bill..

Example: imagine that a guest stays in the room for 6 hours, with the air conditioner set to 18° C. When the guest opens a window, Window Sensor W2 will turn the conditioner off. If not switched off by W2, the air conditioning would run freely for 6 hours straight with the windows open, and you would have wasted a lot of electricity in a vain attempt to reach 18°C.
With the combined use of our remote control, even when the air conditioner is running your guest will not be able to set temperatures lower than 22° – 23° C (you decide), guaranteeing you immediate savings on your bill, as testified by many of our customers.

This is why we recommend the combined use of Window Sensor W2 with one of our universal air conditioner remote controls.


Note: The images in the product catalog are for illustrative purposes only. Our company reserves the right to make product improvement modifications without any obligation to give prior notice.

Frequently Bought Together

W1 wireless window-door sensor for air conditioners+SaveOnAirCo R3 Universal Remote Control for air conditioners - Details
Price for all:    75,00


Window Sensor W2 by SaveOnAirCo is a kit composed of 2 items: a receiver, which can cut off the power supply to the device connected to it, and a wireless sensor, which can detect the opening of the window or the balcony door. The air conditioner (or other appliance) is turned off and you stop uselessly wasting electricity and money by trying to cool a room where warm air is coming in through an open window.

Its wireless technology means it can be fitted to any air conditioner already in use, with no need for expensive (and intrusive) masonry work to run unnecessary cables.

Installation is really quite simple, and a electrician can do the job in less than 5 minutes. The sensor must be paired with the receiver (follow the instructions provided with the kit) and then attached to the window, using the convenient double-sided adhesive tape that is also included.

IMPORTANT: Be sure to use the device with a circuit power rating of less than 1000W.
In the event that your circuit has a power rating greater than 1000W, you can adapt it by connecting it to a contactor (see Wikipedia) of the desired rating.

If the window is opened, AC will be turned off automatically!

Additional information

Weight 0,090 kg

FAQ - Frequently Asked Questions

#01 – What is the Window Sensor W2?
It is an advanced wireless sensor that turns off the air conditioner when a window or balcony door is opened. Until the window (or balcony door) is closed again, Window Sensor W2 will cut power to the air conditioner, preventing it from turning on. Once the window (or balcony door) is closed, power will again be supplied to the air conditioner, which will then be able to return to normal operation. This avoids wasting electricity and money by trying in vain to cool a room where warm air is coming in through an open window.

#02 – Why wireless?
For years, hotels have used wired solutions that cut the power supply to the indoor unit when the window is opened. But this type of solution is daunting for hoteliers, because wires have to be run from the air conditioner to the windows, with unsightly wiring or ducting in view, with increased installation costs. Window Sensor W2, with its wireless technology, solves these problems, and costs significantly less.

#03 – How far can the signal reach between the sensor and the receiver switch?
Window Sensor W2 has a certified open field tolerance of more than 30 meters.
Field tests demonstrated that the sensor attached to the window can communicate with the switch fitted to the air conditioner without any problems or any latency, even passing through 2 stone walls of 60 cm thickness apiece.

#04 – Is installation simple?
Absolutely! Window Sensor W2 comes with a small radio receiver that is installed on the air conditioner with an intervention on the power supply. The operation is really very simple, and a good electrician can do the job in less than 5 minutes. The receiver must be paired with the sensor (follow the instructions provided with the product) and then mounted on the window, thanks to the handy double-sided tape provided. Having done this simple operation, Window Sensor W2 is ready to control the shutdown of your air conditioner as soon as it detects the window or patio door open.

#05 – Does the component that’s installed on the air conditioner have to remain visible because of the antenna?
No. In fact, the receiver is so small that we recommend installing it inside the split, so that nothing can be seen at all.

#06 – Could multiple Window Sensor W2 sensors interfere with each other?
Absolutely not. During the installation phase (less than 5 minutes in total) the sensor is paired with the receiver via a “unique digital signature.” This makes it impossible for 2 Window Sensor W2 to have the same signature and create interference between them.

#07 – I have a Wi-Fi router in the room. Can Window Sensor W2 affect or be affected by its presence?
Absolutely not.

#08 – Does it also work with fan coils?
Certainly. Installation of the radio receiver requires a minor intervention on the power supply, as mentioned above. This can be done indiscriminately for both regular split air conditioners and fan coils.
Thanks to Window Sensor W2, fan coils will turn off when your guests open the window.

#09 – Is Window Sensor W2 also compatible with all dual and multi split systems?
Generally, yes. In very rare cases, however, and exclusively on dual or multi split systems, the outdoor motor interprets the “absence” of the indoor unit (to which power has been cut off) as an error and goes into lockout. Before purchasing Window Sensor W2 for dual or multi-split systems, we recommend verifying full compatibility by physically disconnecting power to one of the indoor units and verifying that the rest of the system continues to function properly.

#10 – Can I use Window Sensor W2 together with your remote controls?
Absolutely! By doing so you will save even more energy and maximize the benefits.

#11 – Do you need power transformers?
Absolutely not! The Window Sensor W2 receiver runs on a normal 220 volt power supply, while the magnetic sensor takes a normal AAA battery. The product is then ready to be installed with no additional equipment needed.

#12 – Is it safe for my A/C compressor cutting off the power supply to my split air conditioner while it is running?
Absolutely. First, consider that modern HVAC systems are equipped with built-in delay mechanisms to ensure that refrigerant pressures have equalized before allowing the compressor to start.
Second, remember that the practice of interrupting the power supply to air conditioners has been commonplace in hotels for years; the Window Sensor W2 system is a game changer because it does the same thing without the window sensor having to be wired to the receiver installed in the air conditioner.
Even if this first consideration should be enough to reassure you about the use of the system, we can add that throughout the Window Sensor W2 design phase we were advised by the most experienced technicians in the field, who confirmed that due to the way “split type” air conditioning systems work, there is no criticality to interrupting the power supply to either the outdoor or indoor unit.

At SaveOnAirCo we suggest cutting off power to the indoor unit only, firstly because the very limited current draw doesn’t overload contactor inside our receiver, and secondly because, installed in this way, when the power to the indoor unit fan is cut off, the outdoor unit compressor continues to run for a while and then shuts down naturally, controlled by its own circuitry.

However, because we don’t install our own devices, SaveOnAirCo cannot be held responsible for any damage to an air conditioning system, so if you have any doubts, we recommend that you consult your own trusted installer before purchasing our systems.

#13 – Can Window Sensor W2 be installed to monitor 2 or more windows from a single air conditioner?
The Window Sensor W2 system is designed to monitor 1 window per air conditioner. However, you can easily overcome this technical limitation with some additional components – namely a simple and inexpensive monostable relay ( see picture ).

To help you fully understand the usage options, we need to explain in detail how the Window Sensor W2 works: the window/door sensor sends an encoded digital radio signal every time the two parts of the sensor are moved farther apart or closer together. The signal is read by the Window Sensor W2 receiver and when the parts move away from each other (i.e., when the window/door is opened) it is interpreted as “opening the circuit” (type A signal), and power is cut off to the device connected to the Window Sensor W2 receiver. When the parts move closer to each other (window/door is closed), it is interpreted as “closing the circuit” (type B signal) and power is restored to the device connected to the Window Sensor W2 receiver.
Although multiple window/door sensors can theoretically be connected to the Window Sensor W2 receiver, its technology can’t manage multiple devices properly, so the system needs to be equipped with a monostable relay.

To explain further, let’s assume we have a system with one Window Sensor W2 receiver and two sensors mounted on two windows, which we will call “window #1” and “window #2.”
If we open and then close window #1, the Window Sensor W2 receiver first receives the type A signal, which is the trigger to interrupt the power supply, and then the type B signal, which is the trigger to restore the power supply; the same happens if we open and close window #2.
The problem arises if we first open window #1 and then window #2, and later close only window #1, leaving window #2 open; in this scenario the Window Sensor W2 receiver would receive the signals in this order: A, A, B. When it receives the first type B signal, it would restore power to the device connected to it, even though window #2 is still open.

To permanently fix this issue, you need to install an Window Sensor W2 for each window/door that you want to monitor, and then connect a single monostable relay to every Window Sensor W2 receiver (see diagram below), like this FINDER relay.

Once a single relay is connected to every Window Sensor W2 receiver, the problem will be permanently solved. Until all windows are closed, power to the system will be cut off, regardless of the order in which the windows are opened or closed.

Monostable relay scheme Window Sensor W2 on 2 windows
Monostable relay scheme Window Sensor W2 on 2 windows
Monostable relay scheme Window sensor W2 on 3 or more windows
Monostable relay scheme Window sensor W2 on 3 or more windows

25 reviews for Window Sensor W2 – Wireless sensor for windows and balcony doors that turns off air conditioners (V2)

  1. Michael


  2. Elsa

    Works great, much appreciated by my electrician

  3. R. Rooms

    Excellent product, satisfied.

  4. Ilaria

    Very satisfied with the product, intuitive installation and easily installed in a few minutes. Its functionality is perfect, very precise seller and very fast communication.

  5. Rosario

    Excellent product, clear and intuitive diagrams. Works properly.
    Product connected to an LG Dual Split air conditioner.

  6. Nicola

    Satisfied with the purchase (6 kits). SaveOnAirCo company is professional and well organized. Excellent communication. Quick delivery. Everything perfect.
    Fair price. I highly recommend the Window Sensor W1 product.

  7. Massimo De Togni

    As an engineer, I appreciated the ease of installation and the uniqueness of the solution. Transforming an old farmhouse with stone walls into a guesthouse, it solved many problems for me.
    I’m confident that the frequencies are stable and not subject to interference.
    I will update you in a while.
    For now, very satisfied. I will also buy the remote controls.
    Well done.

  8. informaticomatteo

    Convenient product and not easy to find. Customer support works well. They helped me very quickly.

  9. Andrea

    Great product. Arrived very quickly. Very satisfied. Recommended to all.

  10. Massimo

    Excellent product, I purchased four and they work perfectly. Easy programming and installation inside the aircon unit. Very satisfied…!!!!

  11. Massimo

    I installed some Window Sensor W1 in a guesthouse. I am a professional technician, and I must say that the installation was extremely easy. They work perfectly. Definitely recommended for those who want to save money in both winter and summer. A small investment that pays for itself in savings.

    Massimo – MB Elettroimpianti

  12. Riccardo

    The kit is extremely intuitive and easy to install: the sensor attaches with the double-sided adhesive tape, and then to connect the receiver to the air conditioner power supply you only need to join 2 cables using the terminals that are supplied with the kit. It works as it should by cutting off the power supply to the air conditioner as long as the window is open.
    I am very satisfied with the purchase which will allow me to save money on my electricity bill and create less pollution!

  13. Giovanni

    I just set it up, very easy to install and for the moment it’s working well. Perfect, let’s hope it continues in the future.

  14. Energy easy

    Great system for reducing energy consumption

    Gennaro S.
    energy easy srl

  15. Maurizio Serafini

    Good product, great customer support, their correctness exceeded expectations

  16. Antonino Di Maio

    I bought the sensor for the air conditioner. The product met my needs. I highly recommend it to everyone who needs to turn off the air conditioner when opening doors and windows to save energy.

    Antonino Di Maio

  17. Patrizia

    I made the right choice, easy installation, works great. Solved the problem. Highly recommended.

    Patrizia S.

  18. Salvatore Modica

    Great product, very easy to install even for first-timers, very reliable. I’ve done some tests and it receives even from considerable distances.

    Salvatore Modica

  19. Ruben

    I had a problem with the first switch not working but SaveOnAirCo staff was very quick to send me a new one. Also, excellent assistance from their technician who talked with my electrician and was able to give the right instructions on how to use the W1 through a special circuit board in the air conditioner that manages shutdown instead of cutting the power to the split.

    Ruben M.

  20. Fabio

    Excellent product, very smart, eliminates the regular pain-in-the-a** of rude customers who leave the windows wide open with the air conditioner on at 18°C. It can be installed in minutes even without the help of a technician and there’s no masonry work required.


  21. Palmieri Luciana

    You are great. Prompt shipping and resolution of installation problems. Thank you.

    Luciana Palmieri

  22. Simonati Francesco

    I’m so glad I installed the SaveOnAirCo smart remote control and wireless sensor. No more aircon cranked down to 16 degrees with windows open. I can’t wait to see the savings on my bill. Thank you very much SaveOnAirCo and happy holidays!


  23. Stefano

    Great product. Easy to install and operate. Recommended.

  24. Fabio casa vacanze Le Rose

    Very satisfied, as soon as it arrived, I installed it immediately and that was really easy. Now I’m waiting for the warmer months so I can hear guests (the ones with the windows open) complain that the aircon’s not working.

    Fabio, casa vacanze Le Rose

  25. Paolo

    It always made me angry that guests would leave their windows open with the air conditioning on. I had asked my electrician for a solution, and he told me that to do a wired system would take at least € 120 euros and almost one day of work per room. So even though I was tempted I always put it off. Then I discovered this product, and I am overjoyed and with only € 44 I solved the problem, and I was able to do the work myself in no time. Very satisfied.

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