I have a2012 Honda Civic and the heater heats well sometimes and other times I don't seem to get much heat

Coolant level is low. Thermostat is old. Tend to both these items, and report!

whats the temp. guage say? you may have heat but the door in heater duct is not shifting to devert it

Thanks for your suggestions. Unfortunately my car doesn't have a temperature gauge. The blue light goes off when the engine warms up.

at the very least, open the hood and fill the coolant half full with the green stuff, things may improve if the coolant level is correct. This could be done when you gas up and clean the windows~

if you have a 2012 civic bring it in to your dealer it fully warrantied . I don't think its a coolant problem.

If you's gots no heat, sadly it IS a coolant problem.