Heater blows cold air when first turned on and only turns warm after 10 to 20 min of driving

SOURCE: heater blows cold air

this is a huge problem I have been running into,( is this a northern car) There is a blend door in the HVAC system of the car that switches from cold side to hot side. This door is actuated by a servo motor or vacuum. With your car being newer I would have to say it's a servo motor. This isn't an eassy fix and you might have to take the dash apart. Sometimes the servo motors are accesed right under the dash where the radio compartment is. You have to look under the dash and see if you can see it before you go taking the dash apart.Hope this helps you , Please rate this for me

SOURCE: Fully warmed up; blowing hot and cold; Suzuki XL-7

Its just a vent damper plate not operating, it's like a gate which controls the flow of air,,usually they are operated by vacuum, or cables.
Service center time, unless you are handy with your own repairs.

SOURCE: 2001 Suzuki XL-7. Heater blows hot one side, cold the other.

No ductwork [to the lower vents] under the dash. They are part of the heater core / blower housing is integrated (all one piece).

After reviewing shop manual, we suspect that one of the three damper flaps is not positioning correctly; or debris has blocked one side (which makes more sense given the symptoms).

We're waiting for the temperatures to get back in the plus numbers to check out the physical arrangement.

SOURCE: ac blows hot

If your compressor is working the low side should be 15-38 psi. If you have 100 psi that means the compressor is not doing what it should. Make sure the outer clutch is engaged with the pully. If not A/C system check should be done.

SOURCE: enging heating up

Please check the water level before starting the engine in the early morning.If the water has not come back to the radiator from the overflow reservoir it clearly indicates there is a small opening in the cooling system which breaks the vacuum hence water is not sucked in to the radiator .
I have experienced a small opening (at high temperature ) in the thermostat cover. Once that was replaced problem solved. Also check the radiator cap is in good condition.