Hello, I have a Whirlpool Model W10200947B, propane stove. The fire on my burners are really low even when they are on "high" setting. How do I adjust the flame to be hotter? Or more of a flame. Cooking is very slow. I already adjusted the simmer setting, but perplexed there isn't an adjustment for more flame or hotter flame. Is there any way to do that? Or is the grates too high? I would greatly appreciate some help.