Ford Focus - overheating - jws

The engine fan is operating after a very short time in slow moving traffic. Could it be the sender unit that is at fault?

( I had a complete new fan unit fitted in 2010 when the engine overheated badly due to the fan not operating at all)

Ford Focus - overheating - Peter D

And what does your temp gauge say. Did the repair garage give you a one year warrantee. ? Regards Peter