My remedy for the temp light problem:
- Clean the stainless steel stem of the mouthpiece very thoroughly with ISO and steel wool
- Even a small amount of resin in any of the grooves can prevent the circuit from being completed
- ISO and steel wool all along the stainless steel, including the upper piece of the stainless steel where the small piece moves up and down.
Over time, light resin gets into the grooves and soaking the mouthpiece in ISO is then not enough.
This has been an easy and stable fix for me. I now use steel wool to clean that area in addition to soaking/wiping with ISO and it relieves the issue.