How a two-way circuit works
A two-way switch has no “on” and “off” position. It moves the live between two wires that run to the other switch, which is how you can turn the light on and off from either end. With three points, say on a staircase in a house, an intermediate switch goes in the middle.
When replacing one, the key is working out which wire is the common and which are the switched ones. The markings on an old switch are often worn off, and wire colours in older installations don’t always follow the rules. Getting it wrong won’t start a fire, but the light will only work in some combinations, exactly like a broken switch.
Schneider Electric makes two-way and intermediate switches in several ranges, such as Asfora or Sedna Design. The mechanism and frame are usually bought separately. If you’re replacing one of the two switches, the other can stay as long as it works. For a matching look, people often change both.
Adding a third point, say by the living room door, takes more than a swap. An intermediate switch needs four wires, so a new cable has to be run, often in a chase. Mention it in the order from the start so the bids are comparable.
What usually goes wrong
- A standard switch instead of a two-way one. They look identical, but the far end of the hall stops working.
- Wires connected without checking which is common. The light works in only some positions.
- Looking for the fault in one switch only. Sometimes it’s the other one, or a joint in a junction box along the way.
- Working without switching the breaker off. In a two-way circuit there’s still voltage in the box when the light is off.
Getting ready for the visit
- Photograph both switches and say where they are.
- Describe when the light works and when it doesn’t, for example “only when the bedroom rocker is down”.
- Decide whether you’re replacing one switch or both.
Don’t open a two-way switch just to have a look. The rocker doesn’t cut the power, and with three wires it’s easy to mix something up.
Ordering
All it takes is describing the fault in the app and adding photos. Electricians in Warsaw send bids at their own price, and you pick by reviews and price. Contact details and the address are visible only after you choose. You pay the electrician directly, he issues the invoice, and switches and frames are charged separately from the labour.
If the light starts misbehaving again, the electrician puts his own fitting right. Wires inside the wall and other people’s joints in junction boxes are not on him.
Order in the app
Describe the job, add photos and the address. Tradespeople send their own prices and dates — you pick.
Open the app
