the hot water from the engine does not enter the heater coil placed under the dust board of the car because the water valve controlling it is not being activated. Possible cause no supply of 12 volts or the coil of the valve is already burnt out. Have it check by a professional car aircon technician. But first look up for the fuse of said control possibly you've got only a blown fuse. Try to check the fuse using visual inspection and multitester.
fuses are ok
Replace the heater core. It is leaking.
Heater control valve stuck open. Possible blend air door failure.
Check both the supply and return heater hoses from engine to heater for blockage or clogging: remove them and flush. Also check the inlet and outlet pipes on the engine and heater core for gunk buildup and leakage.
If it is windy outside, you may be getting just enough of a breeze to blow out the pilot light -even though the covers are shut. My heater is in the garage, and even w/ the garage door shut and the covers on the heater shut, very windy weather can still cause enough of a draft to blow out the pilot. You could try to find something to block drafts around the heater such as a hot water heater blanket.
Your heater core may be clogged. Have the heater core flushed and refill the system with fresh coolant.
When the engine is turned off, the car heater can still work by using the remaining heat stored in the engine and circulating it through the car's heating system. This allows the heater to continue providing warmth inside the car even when the engine is not running.
radiation
first of all i hate to say an obvious answer but does the heater motor even turn. Does it blow air at all. The first thing i would check is if the fan motor is blowing any air at all. If not u need to put in a new heater fan motor. first of all i hate to say an obvious answer but does the heater motor even turn. Does it blow air at all. The first thing i would check is if the fan motor is blowing any air at all. If not u need to put in a new heater fan motor.
Your heater core is leaking in it's housing box and blowing moist air through the heater/defroster. Try bardall radiator stop leak. If no help, install new heater core. Chuck.
When your car's heater is on, hot coolant from the engine is diverted to the heater core to provide warmth to the cabin. If the engine is overheating, it could indicate issues such as low coolant levels, a malfunctioning thermostat, or a failing water pump. These conditions can prevent the cooling system from effectively regulating engine temperature, causing the engine to overheat even when the heater is active. Additionally, if the heater core becomes clogged, it can restrict coolant flow and exacerbate overheating.
It could be the high speed heater motor relay is stuck on or the switch itself is broken.
Either the heater core is plugged or partially plugged, the heater control valve is not opening completely or the thermostat isn't allowing the engine to warm as much as it should. Even though the engine seems warm enough, if the thermostat isn't working properly you may not be all the way up to temperature.