Hi . My sister is having problems with her ford focus c max. She says around 3 times a day she is having to fill up the water in her car and when she is driving it is  coming into her footwell at drivers side .obv no garages open as lochdown in uk but she is frightened something goes and the car is completely knackered. She says it makes a noise when driving to so that might help to determine what this leak is and is there anything she can buy like a sealant you pou into the water and it will seal leaks to get her thru til lockdown is over.  Plz help .thanks 

It's the heater matrix seals. I would get it fixed ASAP and try not to drive it much until its topped up with proper coolant or it will end up costing a whole engine. Possible post on fixes below. 

 

I concur, my heater matrix seal went last year with similar symptoms. It's a ***** of a job to repair, but if your sister is still using her car, and is an 'essential' worker, most garages will get the car booked in... The bad news is that although the seal itself costs abut £4 (you NEED a genuine Ford one, generic ones will not seal properly), it's a labour intensive job to get at it.