Its either a bad heater core or a clogged one. They are very expensive.
The most common issue is the heater / climate control valve. This can usually be tested in dual mode and checking for change in air circulation.
Low coolant? Bad thermostat? Heater core plugged,restricted or airbound? Heater control cable or valve not working?
COULD BE A BAD HEATER CORE COULD BE A BAD HEATER CORE sounds like the heater control switch needs replacing.if that doesnt fix it, you need new heater core
Check the following items............... 1. A/C heater controller. 2. A/C heater controller doors.
Low coolant? Bad thermostat? Heater core airbound? Heater core restricted or plugged? Defective radiator cap not building sufficient pressure?
Heater core changed three years ago,I changed Thermostat Heater still blows cool air.
can you please clarify what you mean, do you mean that the front heater blows cold but the rear blows hot or do you mean that when the heating is on cold it blows hot? many thanks paul
the heater blows warm air when fan is on low but blows cold air when fan is turn to higher setting
Get the air out of your heater core.
The heater fan ONLY blows the air, it does not make the temperature of that air. Your heater temperature controls how hot the air is. Adjust your heater temperature for hotter or cooler air.
we changed radaitor & thermastate , now heater blows cold air
heater hoses might have been disconected