There could appear some problems if the heater core gets plugged and it will require replacement or flushing from time to time. When the engine is hot, there are 2 hoses from the engine to the heater core and these could cause leaks at high pressure. You can buy flush kits from auto parts stores or you can use even a garden hose to flush the car heater and the car radiator.
When it comes to car heater and radiator problems, the most common one is low engine coolant level. You should always check it before you go on a long journey. Also, if you’ve got an older car you could have faulty engine thermostat and that should be changed at car repair shop.
When you enter the car you should check the temperature gauge and make sure it’s in the normal range. You could also check the temperature yourself by using a metal case thermometer placed into the filler of the radiator when the engine is cold.
If temperature and fluid level are good and you still have heater problems then it might come from poor circulation through the heater core. Test that by keeping your engine running at good temperature and try to feel the heater hoses. Both hoses should have the same temperature. If their temperature is different you should try flushing them or replacing them.
When you’re working around the car heater always use caution because it could be very hot and never try to work at it while the engine is hot. You should also use some gloves to protect your hands from being burned.