2005 Impala No Heat

[maxman]

No heat. Not in defrost. Not in heat. Not through vent. Cold air only. Both hoses to heater core are hot. AC works fine. Air goes where directed with control. Coolant level is up to par. Thermostat only 1 year old as I went through this last year when I also flushed the system due to the same problem. That did not work. I was able to resolve the problem by disconnecting the lines and flushing it out with a garden hose.

This time, the flushing did not work. I tried twice. Both hoses are hot, but no heat. My next attempt will be to reverse the flow through the heater core by switching the hoses.

Any other ideas?

[Karpman1000]

either the heater control valve isn't opening or the heater core is plugged. you might have to take the heater apart to diagnose further.

[maxman]

If I put hose pressure into either line to the heater core, and I get good flow through it, doesn't this mean that the core is not plugged?

If both hoses are hot leading to and from the heater core are hot, doesn't this mean that the core is not plugged?

Problem is, in prior years, I was still able to resolve the problem by pushing garden hose pressure through the core.