Chevrolet Repair: Chevy Blazer 2001, chevy blazer, rad cap

Question
I have a no heat problem with this vehicle I changed antifreeze and thermostat but no resolution. Notice also when I increase the temp control for higher temp the fan seems to loose speed????????

Answer
Hi Tony... did you bleed the cooling system.... you could have an air lock... take rad cap off, run truck till you get up to temp...keep an eye on the coolent level.... once thermostst opens level should go down...top up and watch as it may do this a couple times...once you think you have it full top up coolent recovery bottle and close system..you should have heat...if you have a plugged heater core you can check by feeling the hoses that go into it...they should be about the same temp...if one is hot and the other cold check that water pump is working or you have a plugged core....hope this helps