Tightdog

So like it says my heater is only working about half the time. Would my thermostat getting stuck open cause the heater not to work? Temp is not fluctuating and I have plenty of coolant. Also burped the system with no luck. I also had a new heater core a couple years ago because of the whole driver side cold passenger side warm problem so I'd hope it's not going out again. Any insight will be appreciated.