Rule example: Engine heater based on temperature

Probably would have been more appropriate to start a new thread.

In the future, when posting code How to use code fences.

I strongly recommend using VSCode to edit .rules files. See Editors | openHAB. It will point out syntax errors. Failing that, always watch openhab.log when making changes to a .rules file. It will tell you if you have a syntax error.

As Crispin says, you have an extra > in your second if statement which is probably causing OH to reject the whole .rules file as syntactically incorrect.

VScode would have underlined that line in red as soon as you typed it.