How long does a steam mop take to heat up? Most models take 30 seconds to 2 minutes. To check they are ready, you can briefly activate the mop , and strong steam should come out even when placed against the floor.  Do steam mops require distilled water, or is tap water okay? Manufacturer guidelines typically state that only distilled water should be used, the reason being normal water, especially in the UK where water hardness is high, will leave buildup inside steam mops and