I just set up a new sealed burner Whirlpool propane gas cooktop to replace a similar 8 yr old broken Kitchenaid unit. I don't like the low flame settings. They are too high for simmering. I am having a warranty repair man come out next week, but I was hoping one of you techie types might have some advice before the repair guy appears. I am afraid that there may be no solutions available.

My original KA was installed and converted by a plumber. I was never pleased with that cooktop. I had to change several orifices several times to achieve reasonable high setting flames that didn't have way too much yellow. Control was difficult to achieve, but we never had issues with low (simmer) settings. In the middle of all my hassles with KA/Whirlpool over these settings, I had our propane supplier out to confirm that our home regulator pressures were correct.

In some respects, this (less expensive) new cooktop is superior to the KA unit. The initial orifices provided for propane conversion were correct. In fact, all high flame settings were all blue flame. My current whirlpool provided installation instructions (and internet advice) state that unlike natural gas, propane flame tips may be slightly yellow. My initial KA instructions said 'no yellow'. Since I had all sorts of extra orifices from the KA difficulties, I tried increasing the orifice diameter by a few percent on two of the burners. One increase continued to give slightly higher blue flame and the other increased with light yellow tips (on occasion). To me, this indicates that my high flame orifices and burners are well set.

However, when I initially turned on the cooktop, all the low settings were almost as high as the high settings. I have a huge tool collection, but found that I actually didn't have a long thin trim screw driver to adjust these low settings. While waiting for an Amazon delivery, I swapped out the original KA gas regulator for the newly converted new regulator. It didn't appear to make any difference. I was reluctant to change regulator since the old one had been in the testing from the propane dealer. However, there actually was a difference; the old one was a 4:10 inches of water pressure nat. gas:propane while the new is a 5:10. I expected that since both were 10" propane, that they would be identical but I suppose it is actually the ratio of 5:10 vs 4:10. Anyway, I have both regulators.

Problem is that after bottoming out all low flame settings, all flames, while much lower, need further lowering to create normal simmer settings. I can see that the low settings do not affect the high settings. Will my repair guy find anything to do or is this cooktop poorly designed? I am older, experienced with gas, and a chemist. The high flames are not unusually high. Ideas?