Heating issues? Water boiling out?

I am a noobie at cars but will do my best to explain the situation. About a week ago we noticed that the temperature gauge was at its halfway mark. A quarter higher than it usually is. Also began noticing that the water that we put into the container would boil out after about 20-30 minutes of driving it. The fan in the front only turns on when we have the A/C on. We originally thought it was this fan that had crapped out on us, swapped fuses/relays and checked the plug.
We fill it with water every time it boils out and will try to keep the a/c going while driving it to keep the temperature down but do you gs have any advice or input for me? I've been to two different mechanics and theyve told me that the problem is two different things.
Edit: we have observed for leaks and can not find any. The only liquid that is departing is the water that boils out. With the a/c on the temp stays low because the fan is on, I think. Also if it matters the a/c does not actually blow cold air or anything. Hasn't for about a year haha.

Welcome to the forum!

You sound like you know what you are doing already! The water is getting too hot that is for sure, the fan should be running the whole time though (I think it does, I need to look at mine real quick;) ), if the fuses/relays check out, then the fan may be bad, I honestly would look over all of the fuses and relays again just to double check.

The t stat housing may be causing the issues as well. What is the year? If you have a plastic one (04-06) I would say to replace it anyways with a metal one and see if that was the problem.

Lets see what anybody else says though, I do not know a whole lot about the fan up front, I may be missing something here.

check the thermostat, check compression (cylinder leak down would be better) and if those both check out, check the water pump.

Thank you for the replies. I am driving a 2007. Took it in to the mechanics. They said there was a crack in the container that holds the coolant and water and thus replaced it. They told me that everything is running fine now. The water in the new container is still really hot still and will only boil out if you open the container top after driving it for only short distances. Also, the termostat meter is levels out around halfway or two quarters. Can anyone confirm this as proper temperature or behavior during hot weather?
though I have been driving it for a while, I can't seem to remember what the normal temp was. Don't know if I'm right at saying its a little high or being paranoid.

GM cars run hot, and down south, it is too damn hot :D

If you do not lose anymore water, you should be fine. How many miles are you at now (timing belt done if at 60k>?)

Just keep checking your fluids everyday though to see if you are losing anything now.