So MOT was due and i decided to just do a quick inspection before the test was due. Noticed the expansion tank was low so i put in some ready mixed 50/50 anti-freeze and like an idiot i didn't screw the cap back on. So i drove around for about 10 miles until i turned the engine off and noticed some gurgling sounds coming from the engine bay, opened the hood and low and behold, no cap, and the car has been boiling off the coolant for a while. I remembered i had an old cap from a corsa c and put that on and topped up the coolant half way. However, since then i haven't got any hot air blowing, car still starts fine and i don't notice any loss of speed or rough idling. I also noticed a white foamy substance, really hoping it isn't oil and i've got a bigger problem looming. I do take REALLY REALLY short trips, I'm talking 1 mile. So i thought it might be due to condensation or something.
This was the state of my coolant tank before i gave it a quick clean out.
After flushing the system and filling up the coolant again it did go past the half way mark probably due to thermostat opening so i use a syringe to take the coolant out and get it back to the half way line. 10 minutes after squeezing all the pipes and i turned the engine off and the coolant tank was gurgling and all the coolant disappeared (probs into radiator correct me if i'm wrong)