Why we recommend it
It is the indoor step-up product: less compromise than the smaller infrared option, but still more domestically legible than a big outdoor statement piece.
Pro-Line Direct
CenturaHeat 4 Person Full Spectrum Infrared Indoor Sauna
£2,656.08
Full spectrum
A stronger indoor infrared option with a 1800 x 1200 x 2000 mm footprint, 3400W rated power and a fuller spec than the smaller 3 person model. This is the indoor pick when you want more output without moving to an outdoor build.
Footprint:
Heat + power:
Indoor infrared
Higher-output room
Retailer stock, pricing and delivery details can move. Check the merchant page for the live listing.
4 personFuller indoor capacity
3400WStronger infrared output
20ADedicated electrical planning
2-year wood1-year electrical cover
Why it stands out
It gives the indoor side of the category a product with more presence and more capability, while still keeping the overall project simpler than an outdoor sauna build.
Setup note
This still wants proper electrical planning, but it avoids the outdoor groundwork and site-prep burden that the larger barrel and garden rooms bring.
Warranty and support
Pro-Line currently states a 1-year warranty on electrical parts and a 2-year warranty on the wooden structure, with assembly guidance supplied.
Use
What stands outIndoor presence
This feels like a deliberate room build rather than just the biggest unit that happened to fit through the door.
What to planPower + clearance
You still want to plan the dedicated circuit, sight lines and the amount of breathing room the room can spare.
Related read
Need the easier plug-in version instead?
The 3 person infrared model keeps the same indoor-first direction with an easier 13A story and a smaller room footprint.
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FAQ
Questions buyers ask before they commit.
Is this still an indoor-friendly option?
Yes. It is larger than the 3 person model, but it still makes more sense indoors than the outdoor builds if you have a dedicated room and the right power plan.
What makes it full spectrum?
Pro-Line currently describes the heater setup as infrared carbon fibre plus infrared light, which is the key distinction versus simpler infrared-only entries.
Who should skip this?
Anyone who cannot give the room proper electrical planning and a clear dedicated footprint should start with the smaller indoor model or pause before buying.