You may have an air lock in the heater pipes some vehicles are fitted with bleed screws for this purpose.
you might need a heater core
Yes, replacing the heater core should slove the problem.
Heater core could be clogged.
it maybe your heater core is going out recommend replacing it and go from there
Have you flushed the heater core?
no heat can be caused by,blocked heater core insufficient coolant in engine blocked heater hoses from engine to heater core bad heater thermostat bad thermostat in engine bad heater control switch
No heat in your car may be from your water pump going out and not feeding your heater core with enough water to produce heat. First remove your thermostat and see if your car stops over heating. If it doesnt, then you need to replace your water pump. Hopefully you havent cracked your heads. If your car doesnt over heat after removing the thermostat, but you still have no heat in the car. Then its your heater core that needs replacing. Always replace your thermostat whenever replacing the water pump.
Perhaps a bad thermostat and/or a heater core
could be a number of reasons etc bad thermostat,clogged heater core,leaking heater core,
Your thermostat might be stuck open. Does the radiator cap get hot after running the engine for 10-15 minutes? If not, replace the thermostat.
I have 95 cavbalier new heater cor new thermostat puts out very little heat any suggestions
Try flushing heater core Try flushing heater core