heater on my chevy impala 2011 lt

I hope for your sake that it's not the heater core. https://www.google.com/search? q=Chevy+Impala+%2B+2011+%2B+heater+core+%2B+location+%2B +is+it+in+between+the+fire+wall+and+engine+compartment%3F&o q=Chevy+Impala+%2B+2011+%2B+heater+core+%2B+location+%2B +is+it+in+between+the+fire+wall+and+engine+compartment%3F&a qs=chrome..69i57.61981j0j4&client=tablet-android- google&sourceid=chrome-mobile&ie=UTF- 8#imgrc=M_RXK7vh_BAiLM%3A

I had a car with a broken heater and the core was between the engine compartment and fire wall. Bottom line, it was very expensive to replace. Here's a pic of what you might be dealing with, sorry.

You mentioned it works on one side only, does it put out any heat?

Air Flow Control relay look up YouTube about a $30. Per Relay depending on prices in your area Fix it is Inside You Glove Box Remove the Screws and then Turn on your Car to help you find which one you might need easy Fix

I believe you have a duel system heater control unit..its probably bad..id change that first..