2000 Chevy Blazer

Hello - Dan

To better assist you is your vehicle a 2WD or 4WD and please give me your engine size in liter and the 8th digit of your VIN.

Next please check your heater hoses..... Is one going into the firewall hot and the other cool? If so your heater core is plugged.

Let me know what you find

IF it was mine, I would try back flushing the heater core first. IF you can't access the heater hoses going to the heater core to dis-connect them, you need to cut the lines and install a brass nipple to reconnect them afterwards with hose clamps.

Run water with a garden hose through the core first in one direction then the other way until you get a flow going.

Hi Dan

Service Writer is right on..... Please follow his suggestions and try the back flush first. As he is indicating most likely the heater core is plugged. Once you get a good flow both ways..... Fill with coolant and make sure you do a good bleed on the system and let us know what happens.

Thanks Service Writer for your assistance.

Hello -

I have some minor technical difficulty so I can not see the manual on your vehicle right now. But some have a valve on top of the thermostat housing. You fill the coolant, start the car with heater on high and open the bleeder valve until runs steady.

Other wise, fill some and start the car and slowly fill..... You may have to check it a couple of days.