The car is 98 civic vti. with fan on direct
It used to reduce water so had its radiator cleaned. The water loss issue was resolved.
But after a few days the car heated and when I checked the radiator it was empty.
I filled it and checked it regularly no water loss.
Then a few days back the car heated again and the radiator was empty.
After filling it again I drove around 60km and checked the Radiator. It was completely full. A day later drove another 100+ km checked the radiator again and it was completely full.
What could be the issue?