Nissan Repair: overheating, coolant system, hose pipe

Question
QUESTION: what to do if the car is overheating and heater does not work?

ANSWER: if the heater is not working it mean that there is an airlock in the coolant system causing the system to not allow water in the system to cool the engine causing the engine to overheat if this is not fixed it will cause the engine to seize completely and destroy the engine

---------- FOLLOW-UP ----------

QUESTION: how do I get the air out of the airlock?

Answer
try and find the lowest level pipe and place a hose pipe into this end and with a bit of luck it should provide enough pressure to blow the blockage out otherwise it may have a series of bleed screws on the hose pipe to enable you to allow air to escape this is a lot slower that the previous method i told you about but still will work just as well