AC Froze Up

[hunts800]

In the 90's, running virtually full-time, temp set at 75 and it froze up. Can see the coils are covered with ice. Filter was pretty dirty so took it out and cleaned it. Fan set to "auto".
Once ice on coils melts will start back up. Has never done this before, and we have used it extensively in hit weather across the U.S.
Bedroom AC is fine and also running full-time.
Any ideas?

[DQDick]

Filter being dirty will cause that. Turn the fan on to help defrost it, just don't run the unit until it is clear.

[rohrmann]

These are copied and pasted from a Dometic AC manual. It is describing the freeze sensor when used with the CCC II thermostat. The sensor may have failed or come off where it was installed. This is a photo of a sensor used on Dometic AC's.



3) A Freeze Control Sensor connects to the Electronic
Control Box to allow for the prevention of
freezing coils. This sensor lead is inserted into the
Box and plugged into a connector for that purpose.

1) Snap the Freeze Control Sensor (Part No.
3106480.001) onto the return bend of the evaporator
coil. (See figure below).
a. Locate "D" shaped notch in the flange of the
evaporator coil.

[WaltBennett]

You might also think about where the humidity is coming from that's causing the freezing. If you're not in a humid area (Stockton?), it's probably interior moisture causing this. Might vent it out at night to help.