No heat in 2007 chevy colorado new thermstat

could be the water pump not working causing htese sypmtoms

Your thermostat is stuck partly or fully closed,yes,it can cause it to run hot and no heat.Here's a link on replacing. GET 25 GIFT CARD FOR EVERY 100 SPENT ON ONLINE SHIP TO HOME ORDERS

Your present thermostat seems to be stuck in the open position and not allowing coolant to warm to temperature. I think you should have your thermostat changed. This will give you heat. GOO LUCK FRIEND.

If the thermostat was recently replaced, it could be trapped air in the cooling system. First, you need to establish that the thermostat is working. Remove the radiator cap and start the engine. Let it warm up to normal operating temperature on the temp guage. Make sure the heater is set to the hottest setting. Observe the coolant in the radiator. If the coolant is flowing when the engine is cold, then the thermostat is stuck open and the heater won't get warm. If the coolant is not flowing, continue to watch the coolant. When the thermostat opens, the coolant level will drop in the radiator tank, add antifreeze to bring it back to full. Each time the coolant level drops, add more antifreeze. should the thermostat close while doing this, antifreeze may spill over from the radiator tank. No to worry. As son as the thermostat opens up again, add antifreeze to fill the tank. Continue to do this until the coolant level no longer drops. Sometimes it is necessary to raise the front of the vehicle so the radiator is high than the engine in order for the air to escape. Put the radiator cap back on. If the problem was air in the system, then the heater should be warm now. In the old days we would just drill two 1/8 inch holes in the new thermostat before installing it. That allowed the trapped air to escape slowly. Might still be an option.Let me know if this helps.

make sure you get ALL the air out run it without cap until you see water circulate turn heater to hot NO FAN ABOUT 5 MIN close cap ,see if that works

old school is right, i remember doing that but with the new crossflow it does not apply, if its not getting hot the coolant is circulating

Your thermostat has failed and is stuck in the closed position, thereby not letting the coolant circulate through the radiator.

a common cause for this is a stuck-closed thermostat, which would disallow coolant from circulating from the engine to the radiator. take the cap off the radiator and see if you can visualize the coolant circulating. if the coolant is just sitting there stagnating then that's probably the issue

find where top hose comes from the radiator into the engine block, then drain some of the coolant out and remove hose and thermostat from the block. remember which way the termostat sits in the block and install new one. its always a good idea to flush your cooling system before putting in a new thermostat. if the old one was plugged up, the gunk thats in your system will just plug up the new one in time too. you can get a bottle of radiator flush from most auto parts stores.

You need to check your coolant level first. If it is low you have a coolant leak. No hot coolant=No heat