The heater blow cold not hot air - 2002 Mitsubishi Lancer

SOURCE: heater blows cold air

Check your coolant level, if it's low u won't have adequate heat. If that isn't it, let me know.

SOURCE: 2003 Mitsubishi Eclipse GS blows cold air in heat mode.

ok here we go and you aren't going to believe it...
I replaced the thermostat step one

I noticed that I had a small leak at the engine side of upper hose fixed that by taking it off and cleaning it and putting the hose back on Step two

then while refilling the reservoir with coolant i found that the hose that was supposed to be in the fluid was curled up on top and not sticking down in the fluid where it should be.
played with the hose until i got it to fall down in the reservoir where it should be Step 3

I started the car with the radiator cap off and let it run until it got to normal operating temp. and keep filling the radiator with fluid until the level stayed constant. Then put the cap back on and test drove. Everything worked fine haven't had that much heat in awhile and it kept blowing hot even when i stopped and let it idle for ten min.during test drive. Checked reservoir when I got home and had to add a small amount of coolant but not much.

I really think that the hose in the reservoir not being in the right place and pulling air into the system instead of coolant is the real culprit of this drama, but i replaced the thermostat to be safe.

SOURCE: lancer 1993 heater won't go but blows cold air not hot

Your question was not too specific, so I will assume the blower works but you are not getting any heat. First, check your coolant level. If it is too low then the coolant isn't getting circulated to the heater core. Second, check your heater control valve. If it is not opening then you are not getting any coolant flow through the heater core. If neither of those work, you can buy a 12 volt electric heater to plug into the cigarette lighter from a low price mail order supplier whose name I won't mention, or if you still have full coverage on the vehicle, you can leave the keys in the ignition, leave the window down, and park it in a bad neighborhood.

SOURCE: heater wont blow hot air in van. How do i fix it?

add coolant to the radiator and it should help circulate it and warm the air up

SOURCE: Mitsubishi Eclipse Ac and heater problem

cold air on passenger side of car and warm on drivers, why