Dimplex
Dimplex Optimyst RGB Cassette 20" - CDFI500-PRO-RGB
Dimplex Optimyst RGB Cassette 20"
The Dimplex Optimyst RGB Cassette (model CDFI500-PRO-RGB, Dimplex product number 500004172) is the building block of the Optimyst range. It is not a finished fireplace — it is a 20-inch water-vapour flame engine that you drop into a firebox of your own design, and that is exactly why architects and custom builders use it.
Ultrasonic transducers atomise water into an ultra-fine mist and RGB LEDs light it from below, so what rises off the ember bed is real three-dimensional vapour that rolls and curls the way smoke does — because it is behaving like smoke.
The Point of a Cassette: You Can Link Them
One cassette gives you 20 inches of flame. Two give you forty. Three give you sixty. They are designed to be connected end to end, so the fireplace can be any length your design calls for rather than any length Dimplex happens to sell — and that is something no finished appliance in the range can do.
It also means the cassette suits installations a boxed fireplace cannot: see-through walls, room dividers, a fire running the length of a bar, a hearth built into joinery. You build the enclosure; the cassette makes the fire.
It Produces No Heat
The Optimyst cassette is a flame effect only. There is no heater in it at all. The vapour is cool, the glass is cool, and nothing in the room gets warmer.
If you want a water-vapour fire that also heats, the Optimyst RGB Pro Box carries a thermostatic heater rated to 1,000 sq ft. If you want heat above all, talk to us about the Ignite or BF lines instead — we would rather point you to the right product than sell you the wrong one.
Dimensions
| Cassette size (W x H x D) | 20 1/8" x 9 7/8" x 12" (51.1 x 25.1 x 30.5 cm) |
| Modular | Yes — link multiple cassettes for any length |
| Legs | Four, height-adjustable |
Dimplex does not publish a rough opening for the cassette, and that is deliberate rather than an omission — the enclosure is yours to design. What they give you is the cassette's own size and the requirement that it can breathe and be serviced. If you are designing an enclosure around one or more of these, call us before you build: we will go through the ventilation, the water run and the service access with you, and it is a conversation worth having at the drawing stage rather than the snagging stage.
What the RGB Generation Changed
The CDFI500-PRO-RGB is the current generation. If you are comparing it against the older CDFI500-PRO, Dimplex lists these as the differences:
| CDFI500-PRO | CDFI500-PRO-RGB | |
|---|---|---|
| Flame colour | Single yellow/orange, amber LEDs | Orange, blue, violet, red and aquamarine, plus custom colours in the app |
| Control | Standard remote | Remote and the Dimplex Flame Connect app — colour, brightness, crackle and saved presets |
| Transducers | Two | Three — more mist, denser flame |
| Water safety | 2 solenoid valves, 1 manual | 1 mechanical, 1 absorption, 1 solenoid, 1 manual |
| Water filter | Water-cleaning filter now standard on both | |
| Legs | Four height-adjustable legs on both, up from three | |
The third transducer is the upgrade people notice. More mist means a denser, taller flame, which matters most when the cassette is seen from close up or through glass on more than one side.
Water Supply
The flame is made of water. The cassette has a refillable reservoir, and Dimplex offers an accessory plumbing kit for a permanent mains connection and continuous running.
In a linked, multi-cassette installation, plumb it. Refilling one reservoir by hand is manageable; refilling three in a built-in wall is not.
Flame and Media
- Five preset flame colours — orange, blue, violet, red and aquamarine — plus custom colours through the Flame Connect app.
- Adjustable flame pattern. Included spacers and slots let you shape the flame width and profile.
- Your choice of ember bed. The cassette takes decorative media in its ember tray, so you can finish it with tumbled glass, river rocks or acrylic crystals. An optional inner-glow log set is also available.
- Crackling sound, controllable from the app.
Specifications
| Model | CDFI500-PRO-RGB |
| Dimplex product number | 500004172 |
| Series | Dimplex Optimyst® |
| Type | Water vapour fireplace cassette, for a custom enclosure |
| Flame | Optimyst® water vapour with RGB LED, three transducers |
| Heat output | None — flame effect only |
| Fuel | Electric and water — no combustion, no venting, no chimney |
| Controls | Remote and the Dimplex Flame Connect app |
| Water supply | Refillable reservoir, or the optional plumbing kit for continuous supply |
| Options | Plumbing kit; inner glow log set; your choice of ember media |
| Warranty | 2 years limited |
Documents & Downloads
- Sell Sheet (R01, March 2026) — Optimyst RGB Cassette 20"
- Key Differences — CDFI500-PRO (G3) and CDFI500-PRO-RGB (G4)
- Optimyst Range Handout 2026
- Dimplex 2026 Electric Fireplace Collection
Dimplex publishes no installation manual or single-page technical specification for the RGB cassette on its own — the sell sheet is the only current document, and it carries dimensions but no electrical, water or ventilation figures. If you are specifying this into a custom enclosure, call us and we will get the installation detail from Dimplex before you build.
Warranty
2 YEAR LIMITED WARRANTY from the date of first purchase. Download the Dimplex warranty document. Note that Dimplex excludes Hawaii, Alaska, Yukon, Nunavut and the Northwest Territories from warranty coverage.