No heat

You say that the pipes to the heater radiator in the car are both hot. Is the heater radiator hot to the touch?
If there is a plug inside the radiator, then the hot coolant will not circulate through it and it is necessary to eliminate the cause of the plug, flush the heater radiator.

 

... and when MAX2 says plug, he means blockage. This was my thought, too. Either that or the air blend door under the dash is not working. That should give a B14xx error code, I believe, if that was the problem.

 

There may be an airlock in the heater radiator, or debris from hoses or leak-eliminators may have accumulated. Channels with impaired circulation inside the heater may not allow coolant to pass through. But it may also be that the dampers are jammed. Then the heater heating is localized and does not reach the consumer.

 

So you're saying the hoses that go from the top of the thermostat housing across the transmission right up alongside the inverter pump and up to the water pump that's in between the two brake parts that pushes water into the heater core and then the other line coming from the heater core goes back to the cooling system if those two hoses are hot the one going to the pump and the one going from the pump to the heater core then the heater core is hot inside of the car because you're not feeling the heat only means that a door or something isn't bobbing up and down to try to produce the heat in the car that you're trying to get on your feet or your face. You should also be able to make all of this happen with the radiator cap off of the car just sitting in the driveway the car should sit there and run with the ice engine running as long as there's a call for heat meaning the heat is on high and the fan is on whatever when the engine stops running that's when you feel the hoses that run up to that little pump that shoots the water over to the heater core at that time because the engine shut off the system believes that enough hot water has been made that should start satisfying the consumer if you will so if you know those hoses are hot then that means the heater core inside of the heater box is in fact hot and air is not getting across it to produce heat inside the car that's another problem that's not related to the red stuff in the radiator at all for that you'll be taking off the little square looking motors right next to your gas pedal foot when you're sitting in the car and then you'll be able to move the door that goes from outside cold air and moves the air so that it all goes across the heater for and comes out at any of the vents you selected .

 

Has anybody ever poured a stop leak or gasket sealer into the car? Those products are notorious for jamming up cooling systems. If it is just a "simple" blockage, like from a hose that is disintegrating, then it should be possible to flush it. There are kits with adapters for attaching a garden hose to one side of the heater core, and a drain to the other. Blast it out with water.

If some piece of rubber or other similar macroscopic blockage comes out, the OP's next task will be figuring out where that came from, and it may come down to replacing all of the rubber hoses since inspecting their innards is not really practical.