2000 chevy silverado keeps getting hot. Changed thermostat water pump & flushed radiator. Keeps getting hot.

You have to :burp" the cooling system.

Rather than me trying to walk you through this with text, just google and youtube yourself through it.

Search for things like "Bleeding the cooling system" and you will find a few different ways you can do this.

Just use caution when the water is hot.

could be water pump.

I would start by checking the fluid to make sure it's at the proper level, Then check to see if the thermostat is opening like it should. If you have good flow and you get heat inside the car but the car still overheats I think I'd be checking for blown head gaskets and head warp.

Two ideas.

1. Try a new radiator reservoir cap (trust me, it is very important in holding pressure which keeps the coolant from boiling out).

2. This one you will need an entire weekend to spend on this. You need to remove the thermostat and replace the thermostat housing. pull one of the radiator hoses and attach a garden hose with good pressure. It needs to flush for at least 20 minutes. Then switch directions and flush water where was coming out. Then put it back together and drive until it gets hot. Allow it to cool for 45mins (to prevent engine from cracking due to rapid cooling) and repeat until no crud comes out when flushing.

250 TOO HOT FOR ENGINE AND TRANSMISSION. SOUND LIKE COOLING FAN CLUTCH BAD ITS FREEWHEELING NOT LOCKING UP TO DIRECT DRIVE TOO COOL ENGINE OFF BECAUSE THE FAN CLUTCH THERMOSTAT NOT WORKING THE HOT SILICONE OIL CAUSE IT TO EXPAND TO PUT RESISTANCE ON CLUTCH TO PUT DRAG ON FAN CLUTCH CAUSING IT TO LOCK IN GIVE IT DIRECT DRIVE.I WOULD STILL REPLACE THERMOSTAT AND RADIATOR PRESSURE CAP IF TEMPERATURE STILL 250 DEGREES YOUR RADIATOR AND COOLANT SYSTEM NEED FLUSHING.

Blow out the radiator core from the engine side with compressed air to get rid of bugs and other debris. Check the fan clutch if mechanical drive. If electric fan, make sure fan(s) come on when hot. You may have combustion products entering the cooling system. Check with auto parts supplier for test kit for same or check with a well equipped shop for a similar test. Make sure that both radiator hoses are not obstructed internally. Hope some of this helps!

You may need to change the water pump. When the engine is cold undo the rad cap, start the engine & see if there is any coolant moving through the rad. If not change the water pump & the pump serpentine belt. This should solve the problem unless the headgasket is in bad shape. Good luck!

once truck is warm check both heater core hoses to make sure they are both warm if not then check the cold water valve could be stuck shut not allowing coolant to travel in to heater core.

Is the fan clutch working? Also check for something blocking the radiator. like paper or some other sort of road debris.

Flushing the radiator, replacing the radiator cap, adding new coolant, replacing the sensors and a new thermostat solved the problem. Probably didn't need to do all of these things - but since we just purchased the truck, and given the fact that is probably hadn't been done in a while, we chose to do all of these things (which really didn't cost a whole lot), it's running like a charm now.