I'm pretty much at my wits end with the wife's Blazer. It's got a brand new blower and I did a full flush just a few months ago. The coolant temp gauge goes up slowly and as far as I can tell reads just fine. When I adjust the heat setting and climate controls I can hear and feel everything in there working as it should but alas...no heat. Ideas? It's gotta be something stupid I'm overlooking.

 

What is the ECT reading when the engine is at operating temperature?
Are both heater hoses hot where they enter & exit the heater core? Both hoses should be very close to the same temperature, and almost too hot to hold with bare hands.