Domus THERMAFLOW 4-in-1 Round Bathroom Heater

The Domus THERMAFLOW 4-in-1 is a round bathroom heater, exhaust fan, circulating fan and light — 2,150 W, 240 V, 300 m³/h extraction, Ø330 mm cutout, in white or white/black.

⛔⛔⛔ Its power field says 12 W. The appliance draws 2,150.

• ⭐ The record publishes power_watt = 12 W. ⭐ That is the LED light's wattage. ⭐ The heater's total load is 2,150 W. ⭐ An understatement of about 180 times.
• ⭐⭐ WE CHECKED EVERY BATHROOM HEATER IN THE CATALOGUE, AND THIS IS THE RULE RATHER THAN THE EXCEPTION:

• ⭐⭐ EIGHT OF NINE PUBLISH THE LAMP'S WATTAGE. ONE PUBLISHES THE HEATER'S. ⭐ The understatement runs from 72 to 187 times.
• ⭐ WHY THIS MATTERS MORE THAN A NUMBER ON A PAGE: ⭐ 2,150 W at 240 V is 9.0 amps, and a standard 10 A lighting circuit carries 2,400 W. ⭐ THIS APPLIANCE IS 90% OF THAT CIRCUIT ON ITS OWN.
• ⛔ A buyer or estimator reading “12 W” would take it for a light fitting and never provision a dedicated circuit. ⭐ It needs one, and adding it at rough-in is routine where adding it afterwards means chasing walls.
• ⭐ TELL YOUR ELECTRICIAN THE REAL FIGURE BEFORE THE WALLS CLOSE.

⭐ What "4-in-1" actually means here

• ⭐ Heater, exhaust fan, circulating fan and light — four functions from one ceiling opening.
• ⭐⭐ THE CIRCULATING FAN IS THE ONE WORTH UNDERSTANDING. ⭐ A conventional bathroom heater blasts heat downward and the warm air rises straight back to the ceiling, so the room feels hot under the unit and cold everywhere else. ⭐ A circulating fan moves that air around instead of letting it stratify.
• ⭐ Domus calls it “Heat Breeze” and pairs it with low-level extraction running at the same time — ⭐ so the room is warmed and moisture is drawn off simultaneously. ⭐ That combination is what actually reduces condensation, rather than heating alone.
• ⭐ It uses a PTC heating element. ⭐ PTC elements self-limit: their resistance rises as they heat, so they cannot run away thermally the way a bare wire element can. ⭐ In a ceiling cavity full of insulation that is a meaningful safety property.

⭐ 300 m³/h — read it against the room, not against the bigger models

• ⭐ 300 m³/h in a 10 m³ bathroom is a complete air change every two minutes. ⭐ That is adequate for a typical domestic bathroom.
• ⚠ The slimline STREAM model moves 500 m³/h, ⭐ so if the bathroom is large, has a spa, or the shower is used back to back by a household, the higher rate is worth having.
• ⭐⭐ THE DUCT IS WHAT DELIVERS THE FIGURE, NOT THE FAN. ⭐ This unit uses 100 mm ducting where the STREAM uses 150. ⭐ A narrower duct is more sensitive to bends and sags — every elbow costs airflow and adds noise, and a long flexible run with dips in it can halve the effective extraction.
• ⭐ Keep the duct short, straight and rising slightly to the outlet. ⭐ A 3 m flexible duct and an exterior grille are included.

⭐ Ø330 mm cutout in a Ø350 mm fascia — check the joists

⭐ The fascia covers only 10 mm around the cutout, which is very little tolerance. ⭐⭐ A Ø330 mm hole is also wider than the 300 mm clear gap between joists at 450 mm centres — ⭐ so it will almost certainly need a joist trimmed and noggins added, which is a carpentry job rather than an electrical one. ⭐ CHECK THE JOIST DIRECTION AND SPACING BEFORE ORDERING, ⭐ because the cutout is the one dimension that cannot be corrected once the ceiling is cut. ⭐ At 3.7 kg it also needs fixing to framing rather than to plasterboard.

⭐ The light: 850–950 lumens across three colour temperatures

⭐ 12 W giving 850 lm at 3000 K, 950 at 4000 and 900 at 5000, CRI ≥80. ⭐ THAT IS NOT ENOUGH TO BE A BATHROOM'S ONLY LIGHT in most rooms — ⭐ the larger STREAM gives 1,850 lm. ⭐ Plan a separate ceiling or vanity light alongside it. ⭐ CRI ≥80 is also adequate for general bathroom use and not for close colour work, so a higher-CRI vanity light is worth having if anyone does makeup in the room.

⭐ IPX2 and where it may sit

⭐ The rating is IPX2: the X means solids were not rated, and the 2 means protection against dripping water at up to 15° tilt. ⭐ That is the lowest water rating in common bathroom use, and it places the unit in a ceiling position outside the shower zone. ⭐ Normal for a heater — it needs airflow through it, and a sealed heater is a contradiction — but it means the rating decides the position rather than where the heat would be most welcome. ⭐ Confirm the zone with your electrician against the current wiring rules.

✅ What is published

Where it works

• ⭐ Bathrooms with a dedicated circuit — ⭐ plan it at rough-in.
• ⭐ Rooms where stratification is the problem — ⭐ the circulating fan.
• ⭐ Ceiling positions outside the shower zone.
• ⚠ Not as the room's only light — ⭐ 950 lm.
• ⚠ Not ordered before checking the joists — ⭐ Ø330 mm.

Specifying it

Round 4-in-1 bathroom heater, exhaust fan, circulating fan and light. 2,150 W at 240 V AC, 60 W AC motor. PTC element. 300 m³/h extraction, 100 mm duct. Light 850/950/900 lm at 3000/4000/5000 K, CRI ≥80, 12 W. Cutout Ø330 mm, fascia Ø350 mm. 3.7 kg. IPX2. 6-switch digital wall controller, 3 m flexible duct and exterior grille included. ⛔⛔⛔ ITS POWER FIELD PUBLISHES 12 W — THE LAMP'S WATTAGE — ON A 2,150 W APPLIANCE, an understatement of about 180 times. AND IT IS THE RULE RATHER THAN THE EXCEPTION: eight of the nine bathroom heaters in this catalogue publish their lamp's wattage in place of the heater's. ⭐ THE REAL FIGURE IS 9.0 AMPS — 90% OF A STANDARD 10 A LIGHTING CIRCUIT ON ITS OWN. It needs a dedicated circuit, nothing says so, and a buyer reading "12 W" would take it for a light fitting.

Supplied and supported by Lights For You.

Download Datasheet (PDF)

Download Datasheet (PDF)