I have two issues with those type of heaters - First - the catalyst element do ablate and wear out over time. You often cannot tell from looking at the heater if it is good or not - the only way to tell is to light it up and turn off the lights and watch the top - it should ALL be glowing a dull red. If it is worn off - then only the edges will glow.

Second - There is really only two ways to full stop the catalyst heat process and that is with the snuffer or when the wick is fully dry and no Coleman fuel remains in the tank.

I've had a disassembled unit fire back up when the wick and head unit were doused in water while OFF the tank!

(there was still fuel on the wick) Thankfully it was in the driveway on concrete ot it could have been much worse. To me those heaters are just shelf queens or a display curiosity. Not worth the hassle for me