Low temp on display but engine is hot and boils over if stationary.

[Roberts1408]

The in car display says the temperature is low. If the car is standing still on idle it will boil over but display is still low to normal temperature?
Does the Ecu control the fan from the same sensor that displays the temperature? Or could it be the location of the sensor and the water pump not circulating?

 

[Pedro]

Thermostat maybe goosed their electronically assisted to operate when the ECU had received the data on engine temp from atmospheric sensor in the door mirror the coolant temp sensor & the Thermostat from start up this will also control the fan which can run in 60 second cycles detecting temp faults but this can also be related to the fan control module being at fault common issue on Peugeots apparently

 

[Roberts1408]

Thank you. Hoping it wasn’t thermostat as it’s buried under lots of bits.

 

[Pedro]

The thermostat is sealed in a tank so its a straight swop but they are a pain to get at battery off etc