I was stuck in traffic today in my 1998 Felicia gli and noticed that the temperature gauge had climbed to 110. I wasn't sure if the cooling fan had kicked in at this stage but the temperature seemed a bit high for me. I recently changed the thermostat I'm wondering if this had anything to do with it. I wouldn't mind knowing the temperature the ffan is surposed to kick in.

Mine always kicked in jusr over the halfway mark

Might be airlocked if you've done a stat recently?

I did refill the cooling system as it says in the Haynes manual with the temperature sensor out

You could be right though about an airlock

some thermostats are bad from new.

cheap quality, wrong temperature, bad calibration.

but I suggest short radiator fan sensor's contacts see if fan starts.

then remove short, let car idle and see if fan starts right above middle marker of temp gauge.

if it does not -> might be fan temp sensor bad if you ruled out air pockets.