My 2001 mazda millenia ran hot, we put water in it and it still ran hot does it sound like the thermostat?

If your car ran hot, you may need to check the radiator for a leak. You always need to add antifreeze/coolant when you add water to your car. Check you owner's manual for the type they suggest and the proper mix of water to antifreeze/coolant. I had to get a head on my motor shaved when my car ran hot and later I had to get the hoses replaced. My radiator cap died following my replacing the radiator as it was plastic and when the car overheated it damaged the cap. How long was the car running hot? You don't want to be a penny wize or a pound foolish when it comes to engine overheating problems. You can repair on the cheap now and pay a lot more in the long run. Also, in the future when your car runs hot, you can turn on the heater --yes even when it is hot outside--I recommend opening up the windows. The heater fan will help to dissipate the heat from the car engine. It does work. I hope these help. Also go to a reputable repair shop. It could be your thermostat they can have check valves which get messed up but you need to check to see if it is your radiator or if there is a leak there or in a hose.

2.5L 2001 Mazda Millenia Coolent Reservoir boiling. Oil is not milky,no water out of tail pipes, no antifreeze smell. Changed radiator, thermostat, water hoses. Fans are working.
What can it be? Please help.