Chevrolet Luze's water tank exhausts well. First, air can be discharged directly through the vent above the water tank.
Water can also be added to the water supply pipe and heating pipe one by one and discharged from the heating water tank pipeline. It is not difficult to exhaust air unless there is something wrong with your water pump. Check whether the impeller of the water pump is corroded.
The basic water tank is not hot, that's all.