Coolant being used up every 900 approx miles

Hi
I have a skoda octavia 2001, 1.6L, my coolant warning light
is coming on from a cold start for example when the car is
left over night, but not any other time. Once I drive the
car for a few mins or leave it idle for the same about of
time, I turn of the engine and restart it, the light goes
of. My coolant is being used up to min level every 900 miles approx.
I have no leak on the driveway where I park it, nor in the
foot well of the car. The car does not over heat in any way.
No other warning lights are coming up and the car is fine
bar this issue. Now before everyone says head gasket, is there anything else it could be?
Thanks

Yes the coolant expansion tank (round plastic tank with a blue cap), and the embedded sensor, hoses and temperature sensor in the radiator (I think there is one). Look for the tell-tale crusted whitish marks where the leak(s) is.

The plastic under-tray may be diverting any coolant leaks away from where you expect to see them.

I had a leak in the bottom of the radiator in my pasaat.

Leak was very slow and the coolant seemed to gather in the cover under the engine that

The coolant also tends to hold in when the system is selaed.

Take the top off the resevoir, and get a torch and have a good lok around.

Otherwise a mechinic will have a cap that can bepumped up to extra pressure on the system to show up and leaks.