Code 4

[weezfido]

I have a Vauxhall meriva B 2012 1.4 petrol been all ok till a code 4 and engine light came on ive replaced manual thermostat, water pump,expansion bottle and still no luck I am replacing the electric thermostat today but any other advice welcome, have flushed and refilled and  bled the system so dont think i have any more air in there so am now a bit stumped  also the R10 gets really hot the minute I turn the car on  any help appreciated..

[FRONTERATECH]

Engine coolant temp sure it is located somewhere else on engine