Got this reply from H&M chat thingy there sales team...
Jasonplocek: Standard machines will do up to 200 degrees, thereafter we are talking about wet, then dry steam.
When you want to produce steam you have to cut the water back and increase the temperature
what are you looking to clean with steam temperatures and high pressure of a pressure washer?
To get to 250 what you are doing is cutting back the water flow, typically by 1/2 so an 8.0 gpm machine will run around 4.0 gpm to get you over the 200 degree mark, the more you cut the flow, the higher temperature will go. we don't recommend this as it causes the impurities to essentially boil out of the water causing damage to pumps and causing the coiul to scale very quickly.