Replace Aging Air Conditioners – Damage
There is another reason to replace the AC when you replace the furnace. If the coil begins to leak it could damage the new furnace. The coil sits on top of the furnace. Leaking water or coolant would damage the furnace causing it to rust, possibly short circuit the electric motor and other components.
We decided to replace both our furnace and replace our aging air conditioner at the same time. After all it was 28 years old and really does not owe us anything. Because it is so old it is inefficient and so we will gain from some of the savings we will get from the new system.
Everyone is in a different situation. We could have taken a chance and just repaired our furnace. This would have cost $800 with no guarantees that there would not be other problems. Apparently our furnace is known for cracks in the heat ex changer as well which we do not want to deal with.
So a big expense, but hopefully the right one in the long term.