It's interesting that Post No. 31 says that the same company wanted to charge $1,700 to replace the coil. Is your system still under warranty? And, I wonder why the coil would be rusted out so quickly if they are inspecting and cleaning it with foam every 6 months. The coil is supposed to be able to tolerate a certain amount of moisture without rusting. The wet filter must have been caused by a leak in the condensate drain pan. My system is more than 4 years old, and the evaporator coil looks brand new and has never been cleaned.

The HVAC companies have a money maker going. Normal use even in Florida should not require much maintenance. Ours is 20, a Trane and still going strong. Lots of wasted money on unneeded service contracts.

This is the correct answer!
 

Your air conditioning system is a sealed system there is nothing to service. The air handler if electric or the furnace if gas are also sealed bearing and fixed systems that require no maintenance. Rinse the fins top to bottom on your outside unit with a hose and keep your drains clean. 30 years experience heating and ac. Save the service money and get your next unit for free...

I'm glad I had service this year. The 2 yr old unit was 10% low on freon.
It's such a small leak they weren't able to pinpoint the location at this time.
Chuck Farrell didn't want to start arbitrarily replacing parts.
They will be back out in the colder months when they can get more accurate readings.