Could be upside down but that wouldn't prevent the water from getting more that just warm. Most states require the mixing dealybob inside the housing , to be set a point that it won't scald when it's all the way over to hot. I find that set to low for me so you can adjust this so you'll mix more hot than you currently are. Personally and especially if you have kids, I wouldn't totally move it to the hottest position but somewhere hotter than you have now.