I live in an old but gut renovated apartment. There is a ceiling light fixture (LED based) in the living room. It is controlled by two-way switches. I want to add a dimmer to control the light. The LED power supply (ESS015E-0350-42) can receive a Triac-modulated signal. The wires powering the ceiling light are not accessible (hidden in the drop ceiling, and I don't want to open it).

My plan is to install a Triac dimmer such as this one that I will control with a remote. The dimmer documentation says there are two inputs (L and N) and two outputs (L and N).

My problem: I only have access to the 2 switch boxes of the two-switch system, but these boxes have only Live wire, not Neutral wire. The Neutral wire goes directly from the electric panel to the lamp.

My question is: Can a Triac dimmer work without a Neutral?

Thanks for your help!

  • 2
    Yes, simple Triac dimmers can work without neutral - but what you have there is not a 'simple' Triac dimmer - yours has a remote control instead of a knob or slider on the dimmer. There probably do exist remote-controlled dimmers which do not require a neutral connection, but that's not one of them.
    – brhans
    Commented Jan 30, 2022 at 18:10
  • 1
    That is not a triac, that is a dimmer. It probably contains a triac, but that isn't relevant. Your question is about using that dimmer, not about using a triac.
    – marcelm
    Commented Jan 31, 2022 at 8:00

1 Answer 1


Not junk bought mail order

Noting that the seller is not Amazon. You're dealing with the ugly side of the platform, which is essentially eBay. It's populated by cheap junk from Alibaba. A quick search of Alibaba will turn up that very unit, for a fraction of that cost.

This stuff is all junk. It's not safety-rated to handle mains power, doesn't have anti-arc PCB slotting, it's not made of the right plastics to not start a fire if it burns - watch any Big Clive teardown videos and you can watch a rogue's gallery of design shortcuts that can kill you.

What you're looking for is one rated by relevant authorities such as BSI (the famous BSI Kitemark), TUV, Intertek etc.

While the CE logo is supposed to mean that, it is actually meaningless unless there is an EU "bricks and mortar" company standing behind the mark and brand, and who was physically responsible for importing it. Amazon is merely a marketplace connecting independent sellers to buyers, and is not responsible in any way. Yes, it's stored in an Amazon warehouse and ships from there, but Amazon is merely a warehouse service etc. and the item is the far-east seller's property until it arrives at your door. An ingenious loophole, letting them sell garbage and shift all responsibility for consequences onto you.

Charging 30 quid for it is nothing short of a scam.

Not that particular Triac

Even if you had a quality unit, that one isn't the right thing.

You need one that is specifically made for 2-way switch circuits. And certainly, one that is "made to NOT use neutral". Of which many exist, because your wiring scheme is extremely common, especially in 2-way circuits.

Further, they are designed to solve the physical problem of a) fitment in an appropriate location, and b) providing a physical control so "humans who are not you" can also control the light.

What you're really looking for is a "smart switch". It installs in the location of a light switch and replaces the normal light switch. Since the "no neutral at a 2-way" problem is common, there are plenty of triac smart dimmers designed to work with 2-way circuits without a neutral. What they do to power themselves is leak power via the LED light, and either you use LEDs designed for that, or a bypass capacitor made by the dimmer supplier.

Like any smart switch, they can be had in a number of data protocols from HomeKit to Zigbee to X10. They also make wireless remotes, either handheld or "velcro to wall" or designed to fit inside a normal switch box.

  • 2
    Wow, I couldn't dream of a more complete answer, thank you!
    – max
    Commented Jan 30, 2022 at 19:51
  • 2
    Spot-on answer! In the UK, it's probably easier to find one not made for neutral than it is one with it. Neutral is in the ceiling in 'standard' installs, only the live/switched live & earth comes down the wall to the switch. max - I rarely recommend specific brands, but do yourself a favour & pay the premium to get MK. Don't even look at anything cheaper.
    – Tetsujin
    Commented Jan 31, 2022 at 9:14
  • 2
    Great answer. Upvoted. So much garbage being sold on Amazon.com these days. And since Amazon groups identical "looking" products together in a single listing, the reviews have become worse the meaningless. You have no way to know if the reviews are for the product you will actually receive. Plus, even some of Amazon's own products have big problems. Read about their 9V batteries catching fire. Bottom line: spend a little more and buy from a local store whenever possible. You'll help keep them in business and have a human to speak to in person if there are ever any issues. Commented Jan 31, 2022 at 16:30
  • Regarding the "CE" logo: I never looked up if it's true but according to The Internet there's "CE as in conforms with EU" and "CE as in China Export". See e.g. this figure. The EU CE logo aligns on two tangent circles, and the middle bar of the E is shorter. The amazon screenshot looks like the other one. Commented Jan 31, 2022 at 20:35
  • 1
    @AndrasDeak that one actually seems to be an urban myth according to Wikipedia (aka one of the less unreliable sources on The Internet): en.wikipedia.org/wiki/CE_marking#%22China_Export%22
    – CompuChip
    Commented Feb 1, 2022 at 8:07

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