The warm wind in Yi Rui, mazda 6 doesn't work

1 Check whether the thermostat is installed, 2 check whether the hot and cold water valves are open, whether the water valve is installed on the water inlet pipe from the machine to the small warm air tank, 3 check whether the hot and cold air valves of the bellows are open in place, 4 check whether the evaporation tank of the air conditioner is blocked, because if the evaporation tank is blocked, the air volume of the fan will decrease, 5. The warm air tank is blocked. When winter comes, it is necessary to replace the air conditioning filter in time to avoid affecting the warm air volume and air quality. If your hot air can't blow the windshield,