Unless you just installed or had the thermostat installed recently, I would not point at the thermostat as the problem. With what you have described I would suggest have your units serviced as it sounds like a loss of charge, or failed defrost control board. The "Aux" comes on when the unit is using secondary heating (electric heat strips). That occurs when the demand temperature (what you set it to) in Heat mode is more than the current room temperature, usually ~2-4 degrees higher. Also happens in defrost mode. Defrost is a heat pump cycle that melts any build up of ice on the condenser unit (outside unit). That process is simply the unit running in cool mode which will heat up the outside unit to melt any ice. Defrost cycles vary with manufacture but usually you can tell if is in defrost by looking at the outside unit, during defrost the unit will be warm or hot sometimes there is steam and the compressor will be running but not the fan. Defrost only happens on heat pumps in "Heat" mode. Rheem has a 10 yr compressor and parts warranty, so call the installer or Rheem authorized service company.
Conflicting information in the link. My best guess is 2010 Month 11.The only way to be sure is to phone them.EDIT to Add./ I just noticed you typed 'Whirpool', I have edited your post but am not able to edit my link. When it opens, add the 'L' and press Enter.https://www.google.com/search?q=How+old+is+Whirpool+Gas+Range..
I am a retired career chef, and had this one oven with choking CO in an airport catering kitchen. We had it serviced and it was fixed. It sounds like yours is not getting enough air mixed with the gas. Adjusting the gas is one thing but the venturi to the burners can partially block and unburned gas spills over. Remove the burner and venturi and boil it out in whatever you boil your fryers out with.
Are you on mains gas or propane because the jets are different.
https://www.google.com/search?q=commercial+oven+emitting+too+much+Carbon+Monoxide
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Here is text followed by a YouTube. Possible reasons why your oven won't turn on even though the gas and range hood are working:
Igniter: The igniter is responsible for lighting the gas in the oven. If it's faulty, the oven won't turn on. You can check if the igniter is working by looking for a glow when you turn on the oven. If there's no glow, it's likely that the igniter needs to be replaced.
Wires: The wires that connect the oven to the power source may have come loose or be damaged. Check the wires for any signs of damage or looseness and replace them if necessary.
Safety valve: The safety valve regulates the flow of gas to the oven. If it's faulty, the oven won't turn on. You'll need to hire a professional to repair or replace the safety valve.
Top 4 Reasons Oven Won't Turn On - Gas Range Troubleshooting (youtube.com)
