Coolant draining from parked car but no leak identified?

I drive a 2002 Ford Focus. I've been noticing my coolant draining fairly quickly, and my car has come close to overheating a couple times.
I took it to a shop, who told me 3 times there was no leak, and that the issue was with the fan.
Is this normal or should I try another shop?

If there was an issue with the fan was it fixed? The fan is only needed when the car is stopped or moving slowly. If your coolant is draining "fairly quickly" the cooling system needs to be pressurized to find the leak.

Most likely your car is getting really hot so your coolant is running thru and using it so you probably arent leaking first thing i can say is if you arent using anti freeze use it. It will last longer you could check your radiator to see if it working correctly if not that is your issue also you can try running a higher quality oil made to keep the temp down

Are you sure the coolant is leaking? Have you actually checked the level? If you have and it's really going down, then try a different shop. If you haven't, do so multiple times over a realistic period of time (week-month) and keep track. If it is, go to a different shop. If it isn't, then it could a problem with a fan. Still, get it checked out by somewhere else. Also, if it is a problem with a fan, why hasn't this shop fixed it by now?

Check or ask the shop to check the thermostat housing for a leak. They commonly fail on that generation of Focus due to their poor design (the housing has a thin plastic piece built in that holds an o-ring that seals the housing to the engine and that thin plastic often cracks with age/use). A leak there will cause a puddle of coolant to leak under the car as it sits.

If you're interested in checking it yourself, the thermostat housing is a black plastic piece attached to the right side of the engine (as you look at the engine from the front of the car) that has a couple of hoses going into/out of it. If it's wet underneath that piece, you need a new thermostat housing.