Free tool
Dimmer Compatibility Checker
Nine load types, six control types, fifty-four answers. Pick what you are dimming and what you are dimming it with.
Dimming compatibility checker
Most dimming complaints — flicker, buzz, a lamp that will not go below half, a bank that drops out all at once — trace back to a mismatch between the load and the control. The pairings are not interchangeable, and some of them are actively damaging rather than merely disappointing.
The two that cause real harm are worth memorising. A magnetic low-voltage transformer must be dimmed on forward phase; reverse phase can introduce a DC component and cook it. An electronic low-voltage transformer is the opposite, and forward phase on one causes buzzing and early failure. Getting these backwards is a warranty call rather than an adjustment.
The other thing that catches people is minimum load. Dimmers were designed for incandescent circuits drawing hundreds of watts, and many still specify a minimum. Replace six 60-watt lamps with six 9-watt LEDs and the circuit that drew 360 watts now draws 54, which can fall below what the dimmer needs to operate. The symptom looks like a faulty lamp and is actually a control problem.
How to read the answer
The verdict is about the pairing, not about any particular product. Four of the nine load types are drivers, and the driver is the thing actually being dimmed. Match the dimmer to the driver and most of the problem disappears.
Yes means the pairing is what the hardware was designed for. Usually, often and sometimes mean it generally works but the data sheet decides. No means the control type cannot reach that load without something in between, such as a relay, gateway or decoder. Do not try it means the pairing can damage hardware, not merely perform poorly.
Two rules override everything the checker says. The manufacturer compatibility list wins, because it is tested rather than reasoned. And minimum load catches people out constantly: a circuit that used to carry 300 watts of incandescent may now carry 30 watts of LED, which is under the threshold the dimmer needs to run.
The longer explanation of each control type, the retrofit constraints and what goes wrong on site is on the lighting controls guide.
Common questions
Is this checker a substitute for the manufacturer compatibility list?
No. Every reputable dimmer manufacturer publishes a tested compatibility list for their own hardware, and a tested result always beats a general rule. Use this to understand why a pairing works or fails, and to rule out the combinations that can never work, then confirm the specific model against the maker's list.
Why does the checker say never for some combinations?
Because those pairings can damage hardware rather than simply perform badly. Reverse phase on a magnetic transformer can introduce a DC component and destroy the transformer. Forward phase on an electronic transformer or an ELV driver causes buzzing, flicker and early failure. Phase dimming a 0-10V or DALI driver can damage it outright.
What is the minimum load and why does it matter?
Dimmers need a minimum wattage on the circuit to operate correctly. A dimmer specified around a 40 watt incandescent minimum can misbehave when the circuit holds three LED lamps drawing 27 watts between them. The symptom looks like a faulty lamp and is actually a control problem. Some manufacturers publish a companion load resistor to solve it.
How do I dim LED tape?
At the driver or at a decoder downstream of it, never at the tape. If the driver is phase dimmable, a matching phase dimmer works. If it has a 0-10V or DALI input, use that. PWM downstream of a constant-voltage driver is the standard way to get smooth low-end control on tape.
Can I mix load types on one dimmer?
No. One dimmer, one load type. Mixed loads on a single circuit will misbehave regardless of which dimmer is fitted, because the dimmer can only be tuned for one waveform response at a time.
Related: LED dimming compatibility
Still not sure what to specify?
Send the fixture schedule and the control intent together and the project desk will tell you what pairs with what before the order goes in.
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