[cmm002]

OK I had my AC running over night. I woke up and found that the evaporator was ice, but the blower was still working. I shut off the AC cleaned the filter screens thinking that was making it freeze. Turned the unit back on, now I can hear the freon gas running into the evaporator however the blower will not come on to circulate air. Furthermore, I have a dual AC/heating type of equipment, and the blower will come on with the furnace but not with the ac. If the blower was broke why would it work with the furnace just fine but when I turn the AC on no blower action at all? The evaporator is still freezing but I think that's because there is no air circulation because no blower.

[RickJ]

In my experience 9 of 10 cases of ice buildup is caused by a freon leak. I'd call 2-3 HVAC companies out for an estimate... and question them while they are there to confirm they agree on the diagnosis.

Replacing componenets of A/C systems is doable for a diy'er but someone licensed is required when problems need using gauges on the lines.

[cmm002]

I also heard bad air flow is a common problem with freeze-ups.

[RickJ]

Possibly so. I'm not an expert a/c guy - but I usually hear the scoop when we deal with no a/c calls on the apartments I manage.

If you get some estimates and they all agree it's dirty coils, you can say "thank you" then run off to HomeDepot/Lowes for some coil cleaner.

[letmetellu]

Bad air flow can cause a freeze up, and the night you woke up and had the freeze up could have been cause by the motor not funning as well as the dirty filter. There is a relay that turns the fan on for AC... it is possible that some of the water got to it... Does your unit have a circuit board??

[MCC]

It is most likely your indoor fan motor. They have two speeds. High speed for cooling and low speed for heating. The high speed winding is probably open.