Low coolant?
Heater core restricted or plugged?
Heater core airbound?
Water pump not circulating coolant?
Heater control cable not adjusted properly?
With mine it was Heater matrix clogged with radiator sealant. The workshop cleaned it and it's start working fine!
try changing the thermostat With mine it was Heater matrix clogged with radiator sealant. The workshop cleaned it and it's start working fine!
Heater core changed three years ago,I changed Thermostat Heater still blows cool air.
Check antifreeze level, then thermostat next, heater core last
possibly thermostat stuck in the open position?
Try your thermostat
thermostat stuck
some possibilities are. low coolant level, open thermostat, pluged heater core,
Low coolant? Bad thermostat? Heater core plugged,restricted or airbound? Heater control cable or valve not working?
check the thermostat dude may need replacing
It's either the thermostat or the heater controls.
It sound like the thermostat is broken
You probably have a bad thermostat.