overheating - 'Stop Engine Too Hot'

Hi, I'm new to the forum. I have a 2007 1.4i Desire
It doesn't have a temperature gauge but yesterday the display said "Stop Engine Too Hot"

I pulled in and lifted the bonnet, the ignition was off but the fan was running, there was a lot of antifreeze around the inner wing and the expansion tank was overfull, I waited for the fan to stop and everything to cool down and drove home without any problems. Antifreeze is bright pink/red. I'll top it up once its cooled down properly.
The car overheated after a very short journey so I suspect that the thermostat had stuck closed. I've tried to get a new one, the thermostat comes complete with housing, but mine seems to have an electrical connection at the elbow and none of the replacements have.
Has anyone seen this before ? Any help very welcome.
Thanks in advance, Jim L

Welcome to the citroen C3 owners forum loganj1

There is a picture of the thermostat with an electrical connection on ebay, here: Citroen C3 1.4 petrol Thermostat with electrical connection

Sounds like this is the one you are looking for.

The red pink antifreeze is OAT antifreeze, there is a forum post about red OAT here:
antifreeze in a Citroen C3

Overheating is usually the fan, but as you saw the fan running, then the thermostat sounds like a good second place to check.
There are also some temperature sensors to check, which would be less work than the thermostat.

Many Thanks for your reply and for finding the right model, I'll haul the thermostat out and try it in some hot water and if its duff, I'll send for a replacement.
Which sensor do you think it might be ?
Thanks again. Jim L

I think the yellow part on the thermostat housing is a sensor for temperature, but there may also be one that just provides the signal to say 'stop too hot' mounted on the left of the cylinder head.

Citroen C3 Thermostats with temperature sensor fitted - on eBay