Coleman AC freezing up

Constant running with high humidity can cause them to ice up, especially if there is any blockage in the cooling coils. In order to keep them from freezing they need a balance of warm air passing through to keep them from icing, but enough air movement to produce cool air.

Turn off the AC for a while then don't turn the thermostat down so low. The compressor ne3ds to kick on and off so en o.o ugh heat allows ice to melt.

Mach 15's? Ours isn't ducted and does NOT have a Wall thermostat. MUST be run with Fan on HIGH or it will freeze up. You should probably do the same. That said, if yours have wall thermostats, they should be stopping the compressor to prevent what just happened.
Have you ever cleaned them? If the Condenser coils are dirty, the reduced air flow there will promote freezing of some of the condensate water. Then the ice pack can spread across the coil and cause a full freeze over.
Remove the plastic shrouds, then the sheet metal covering the top of the "indoor" coil (properly called Evaporator) on the front end of the A/C units. Clean that coil and the drain pan with the drain holes at the two ends (left and right). Make sure Freeze Sensor is clipped to the Coil.

Freeze sensor may have shifted/fallen off - worth a look.

If you have WALL Tstats, it should NEVER freeze up regardless of how you operate it or the ambient conditions. It has a FREEZE Thermister to prevent it. If it freezes up, either the Freeze Thermister is not installed/correctly or it is defective. To have 2 fail at the same time points to not being installed.
IF you have knob roof top manual control knobs, then freezing is a possibility. The only thing you can do is make sure the Condensor and Evaporator are clean and the AC filters are clea. Run the units on HI COOL and back off the Tstat knob slightly from full cold. Doug

Question Where is the Thermosat/fan/mode switch.

IS it in the ceiling grill? or wall mounted.

Reason for asking.
Many Wall mount controlled units have a 'Frost Sensor" that is a thermal sensor stuck right into the evaporator coils. If it starts to ice up the compressor is shut down for a while.

Coleman "Local control" (Ceiling knobs) do not have this sensor.

How do I know this. ONe is just to my right as I type.. yes it will Ice up
The carrier controlled unit in the back (not a carrier A/C but Carrier controls) has a frost sensor so it should not ice.

Mine have wall mounted thermostats, both have the little sensors pushed into the coil when you look up through the filter opening. There is a very small amount of dust on the filter side of the coil. I will try vacuuming it next time I go down to the camper. I have a picture of the dust when the front AC started to freeze but can’t see how to post.

Thanks
Mike

mlj427 wrote:
Mine have wall mounted thermostats, both have the little sensors pushed into the coil when you look up through the filter opening. There is a very small amount of dust on the filter side of the coil. I will try vacuuming it next time I go down to the camper. I have a picture of the dust when the front AC started to freeze but can’t see how to post.

Thanks
Mike

Replace BOTH of the Freeze Thermisters. Regardless of the condition of the AC parts/parameters, with functioning Freeze Thermisters, the AC CANNOT freeze up. Doug

I'd call that Coil...Dirty.

j-d wrote:
I'd call that Coil...Dirty.

AND he needs to move the Freeze Thermister UP about 4 inches. THAT will fix his problem. Doug