Why does furnace freeze?

Answer 1

The coil you are referring to is the evaporator, it is inside the air-handler, which also contains the heater. The evaporator freezes up when the air conditionong system is low on refrigerant. What happens, is that since the refrigerant is low, it expands more than normal which cools the evaporator more than it is designed to. As the air passes throught the evaporator, moisture in the air freezes on the cold evaporator fins. This will eventually turn into a block of ice, which will impede the air flow. Once the air flow is restricted, the air conditioner will not cool very efficently if at all. Remember that the air conditioner vapor system is a sealed system. The refrigerant will last forever unless it leaks out, so you need to find and repair the leak to stop it from re-occuring. Some companies will just recharge it, especially if it's a very small leak. That way, you'll have to call them again when it starts to freeze up.

Answer 2

When your air conditioner runs during the summer, air blows over the extremely cold cooling coil, through the filters and into your house. When the air moves over the coil, it deposits most of its heat into the coil, meaning that it's cooled down when it moves into your house.

If you have a problem with your air conditioner, either as a result of poor airflow (usually caused by dirty filters), improperly charged refrigerant or even the outside temperature, the hot air crossing the coil will not be able to deposit enough heat. As a result, the coil stays really cold and the condensation on it freezes.

Answer 3

not enof frion, well when u say freezing do you mean its cold or do you mean that ur coil is iceing over and shuting down.