Smart Bulbs vs Smart Switches: My Candeo Dimmer Experience (and the Zigbee2MQTT Lessons Learned)
My smart lighting journey started the way most do: a couple of Philips Hue bulbs as a Christmas present. My wife had no idea what she was getting us into. Honestly, neither did I.
Several years, two properties, twelve Candeo dimmers, and one very specific Zigbee2MQTT rabbit hole later, I have some opinions. This post covers the full arc—from smart bulbs to smart switches, what I'd do differently, and the one pairing problem that cost me weeks before I finally cracked it.
Smart Bulbs: A Great Entry Point With a Ceiling
Smart bulbs are the obvious starting point. You don't need an electrician, you don't need to understand wiring, and you can start with a single bulb for under £15. Philips Hue, in particular, is a polished ecosystem—the app is good, the bulbs are reliable, and the Zigbee integration with Home Assistant works well once you've ditched the Hue bridge (more on that below).
IKEA TRÅDFRI bulbs are worth a mention too. Cheaper than Hue, decent quality, and they join a Zigbee2MQTT network without any fuss. For lamps and secondary lighting, they're excellent value.
But smart bulbs have a fundamental problem: they depend on the switch staying on. The moment someone in your house flicks the wall switch—which everyone does, because that's what wall switches are for—the bulb loses power, goes offline, and your carefully crafted automation is useless. Every smart home veteran has dealt with this. It's the thing that eventually pushes you toward smart switches.
The Hue Bridge vs Zigbee2MQTT
One early decision worth making explicitly: ditch the Hue bridge. Running a dedicated Zigbee2MQTT instance in Home Assistant gives you a single Zigbee network that all your devices—regardless of brand—can join. No per-brand bridges, no cloud dependencies, no monthly fees. Philips Hue bulbs join Zigbee2MQTT without issue; same with IKEA, Aqara, and most other Zigbee devices.
To work around the switch problem in the meantime, I installed Hue Smart Buttons on the walls with blanking plates over the existing switches. It works. I won't pretend it looks good—a round puck stuck to a blanking plate isn't going to win any interior design awards—but it kept the peace while I figured out the right long-term solution.
Moving to Smart Switches
The pivot to smart switches came when I had new driveway lighting installed. A clean slate—I could wire it however I wanted from the start. My first choice was an Aqara no-neutral single switch, and honestly it's been good. Solid build, pairs reliably, and since that circuit is motion-controlled anyway, I've never once needed to touch the physical switch.
When the opportunity came to fit out a whole new property from scratch, I decided to go all-in on smart switches for every ceiling light. No more blanking plates, no more compromises. I wanted switches that looked and worked like normal switches—because everyone else in the house should be able to use them without a briefing.
After watching Home Automation Guy's comparison video on smart light switches, I landed on Candeo dimmers. I ordered twelve.
The Candeo Dimmer: First Impressions
Out of the box, Candeo dimmers look and feel like proper switches. Not plasticky, not oversized, not obviously "smart"—they're just switches. That matters more than it sounds. The whole point is that anyone in the house can use them without thinking about it.
The first installation took about two minutes. Into the back box, pair with Zigbee2MQTT, done. I was convinced I'd have all twelve done by lunchtime.
I was wrong.
The Challenges (And How to Solve Them)
1. Back Box Depth
Candeo dimmers are no-neutral switches, which means the electronics have to fit everything into the module without a neutral wire to power the radio from. The modules are consequently larger than a standard switch mechanism. In several locations, my back boxes were simply too shallow.
The fix is light switch spacers—plastic extenders that give you an extra 10–15mm of depth. Cheap, widely available, and something I wish I'd bought preemptively rather than discovering the hard way. Candeo would do well to include a recommendation (or even a compatible spacer) in their packaging.
2. Minimum Load Requirements
Some bulbs flickered. Others wouldn't fully turn off, leaving a faint glow. This one had me puzzled for longer than I'd like to admit.
The cause: no-neutral switches require a small amount of current to flow even when "off," to keep the electronics powered. This means each circuit needs a minimum load—in Candeo's case, at least 10W total and 5W per bulb. Below that threshold, you get the flickering and ghost-glow symptoms.
The solution is simply to use bulbs that meet the minimum wattage. Most LED bulbs are well under 5W these days, so you may need to check your specific bulbs or swap to slightly higher-rated ones. Once I'd done this, the problem disappeared completely.
3. Two-Way Switching
Stairs and hallways usually have switches at both ends. I assumed I could put a Candeo dimmer at each end. I was wrong again.
Candeo's documentation is clear on this: you can only have one dimmer per circuit. The second switch must be a push/retractive switch (also called a bell-press or momentary switch), not a standard toggle or another dimmer. The dimmer module interprets short and long presses from the retractive switch to control the light.
Once I understood this and replaced the second switches accordingly, it worked—though there's a slight delay on the retractive end that I'm still investigating. The recommendation is to use a matching retractive switch plate; Candeo doesn't currently sell one, which is a gap in their product range.
4. Zigbee2MQTT Pairing Failures: The Missing Coordinator Problem
This one took me weeks. The first few Candeo switches paired instantly and flawlessly. Then, no matter what I tried, subsequent switches simply wouldn't join the network. They'd flash as if trying to pair, and then nothing—never even appearing in the Zigbee2MQTT logs.
I tried resetting the switches, moving them closer to the coordinator, factory resetting Zigbee2MQTT. Nothing worked. I was convinced the switches were faulty.
They weren't. The problem was missing coordinators in my Zigbee2MQTT network.
Here's what happens: Zigbee is a mesh network. Mains-powered devices (like smart switches) act as routers, extending the network for battery-powered devices. When a router device goes offline or is removed without being properly expelled from the network, it leaves a "ghost" entry in the routing table. Other devices—including new devices trying to join—may attempt to route through these ghost nodes and fail silently.
Zigbee2MQTT has a built-in tool to identify these: you can send an MQTT command to request a list of missing coordinators (devices that are referenced in routing tables but not actually present). The command is:
zigbee2mqtt/bridge/request/networkmap
Once you've identified the missing routers, the fix is to remove them from the Zigbee2MQTT device list and re-add any physical devices that should still be on the network. In my experience this requires a few attempts—remove, re-add, check, repeat—and you may need to do it more than once as the mesh stabilises.
After clearing the missing coordinators, every subsequent Candeo switch paired on the first attempt. I still have one stubborn device that may require a firmware update to my Zigbee coordinator—but 11 out of 12 isn't bad.
If you're hitting Zigbee2MQTT pairing failures with new devices, especially after your network has grown beyond about 10 devices, check for missing coordinators before assuming the device is faulty.
Smart Bulbs vs Smart Switches: Where to Use Each
After going through all of this, here's my practical view on where each approach makes sense:
| Smart Bulbs | Smart Switches (e.g. Candeo) | |
|---|---|---|
| Best for | Lamps, feature lighting, rentals | Main ceiling lights, new builds, whole-home setups |
| Installation | Screw in — anyone can do it | Requires basic wiring knowledge or an electrician |
| Switch compatibility | Poor — traditional switches break them | Excellent — works exactly like a normal switch |
| Cost at scale | Expensive (£10–£40 per bulb) | More economical (one switch controls any bulbs) |
| Dimming | Depends on bulb | Works with any dimmable LED |
| Neutral wire needed? | No | Depends on model — Candeo is no-neutral |
My current approach: smart switches for every ceiling light, smart bulbs for lamps where I want colour temperature control or colour, and nothing smart at all for lights that are almost always on a sensor anyway.
What's Next
A few things still on the list:
- LED strip lighting for accent and coving effects — I've always wanted a crown ceiling look and it's getting closer.
- Scene automation — movie mode, evening wind-down, morning wake-up. The switches are all there, now it's about building the automations properly.
- Resolving the last stubborn switch — likely a Zigbee coordinator firmware update is the final piece.
Frequently Asked Questions
Do Candeo dimmers work with Zigbee2MQTT?
Yes. Candeo dimmers are Zigbee devices and pair with Zigbee2MQTT. The first few will pair easily; if you hit failures later, check for missing coordinators in your mesh network before assuming the hardware is at fault.
Do Candeo dimmers need a neutral wire?
No. Candeo dimmers are designed for no-neutral installations, which makes them compatible with the majority of UK wiring. The trade-off is the minimum load requirement (10W total, 5W per bulb minimum).
Why won't my Zigbee2MQTT devices pair after the first few?
The most common cause is missing coordinators — ghost entries in the Zigbee mesh routing table from devices that have been removed or gone offline. Use the Zigbee2MQTT network map tool to identify them and remove them from the device list. New devices should then pair without issue.
Can I use Candeo dimmers for two-way switching?
Yes, but only one Candeo dimmer per circuit. The second switch position must use a push/retractive (momentary) switch, not another dimmer. Candeo's documentation covers this, but it's easy to miss if you're buying switches before reading the full spec.
Are smart bulbs or smart switches better for Home Assistant?
Both work well with Home Assistant via Zigbee2MQTT. Smart switches are generally the better long-term solution for main lighting because they eliminate the switch-compatibility problem. Smart bulbs remain the right choice for lamps and anywhere you want per-bulb colour or colour temperature control.
If you've wrestled with Zigbee2MQTT pairing issues or have a Candeo installation of your own, I'd love to hear how you got on—especially if you've cracked the two-way switch delay. Drop a comment below.