How fast does it heat?

Quartz tubes glow and radiate within seconds of switching on, so you feel warmth quickly when you sit in front of it. The fan helps move that warmth around the immediate area.

Can I use it in a bathroom?

The listing describes indoor use in bedrooms, living rooms and offices and does not rate it for damp rooms. Treat it as a dry-room heater unless the manufacturer says otherwise.

What do the three power settings do?

They set maximum output at 500W, 1000W or 1500W, so you can run low for mild evenings and high for cold ones. The thermostat then cycles the heater to hold your setting.

Does it shut off if knocked over?

Yes. It has automatic tip-over shutoff plus overheat protection, and the housing is flame-retardant.

Will it heat a whole room?

It is a supplemental radiant heater, so it warms people and objects in its path best. For a large or open room, expect it to take the edge off rather than replace your main heating.