You mention freeing up the wand as well as the knob being locked into a half open position, correct? The steam valve could have buildup inside keeping it from moving freely. Best thing to do, and quite easy, would be to take the steam valve apart and maybe give it a quick clean/descale. Often the knob is cranked down tight repeatedly which will damage the seal, then cause it to break away causing issues with the valve/wand function. A full rebuild kit can be had for maybe $15 and DIY to have it like new again.