Flashing coolant warning light.

[pothole]

Question regarding this - manual says it means either low coolant level or fault with engine compartment fan. My coolant level is fine (just above half way when cold) and the compartment fan works normally, too, I believe (I will double check this at the first opportunity).

Anyway, the coolant warning light flashed today. However, it only flashed on one out of three or four start ups. If there is a fault, does it only flash once, or will it continue to flash each time the car is started until the fault is addressed?

The car was caught in a monumental rain storm, so I think it might just be a quirk caused by moisture somewhere, but would be nice to know how the light is supposed to behave.

Thanks.