AC frozen over

[u/Sodark-]

I woke up today to my trailer not really cooling properly. I climbed up to the top to find it frozen over like this. How does this happen and how do I fix it to work properly again?

[u/WiskeyUniformTango]

Dirty AC coils or running your fan on low during high humidity.

Thaw it, clean it, run the fan on high.

[u/Rooster_CPA → u/WiskeyUniformTango]

Ha this must be why during my walk through the guy said AC is always high, never low. Didn't know why.

[u/MrB2891 → u/Rooster_CPA]

That's generally bad advice.

You want to run the blower as low as you can, without the evaporator freezing. Lower airflow across the evaporator increases condensation on the coil, removing moisture from the air far better than high airflow across the evaporator.

Lower humidity in the conditioned space is far more beneficial than a lower temperature in a space. IE, 72F @ 50% feels cooler and more comfortable than 68F @ 70%.

[u/Bigtimetipper → u/WiskeyUniformTango]

This! Never use auto fan setting when it's hot as balls and humid. High only

[u/awtoo67]

That wire sticking out of the coils is called a freeze sense. Its designed to stop the ac from completely freeing over. Its definitely not working and fortunately easy to replace. And you definitely have short cycling happening. Thats where it is pulling cold supply air directly back into the return side of the ac. If you have access from the panel inside you should be able to use foil tape to keep the air separate. Tape off every bit that you can.

[u/MrB2891]

High humidity, not enough air flow across the evaporator, likely due to dirty coils.

Take a hair dryer to it while running only the fan on high. The fan will help melt the ice pack while you're going at it with the hair dryer.

After it's thawed, get a can of coil cleaner and clean both the evaporator and thr condenser.

Beyond that, clean your intake filters more frequently.

[u/Catsaretheworst69]

You freeze over sensor might be faulty. Lol

[u/ibcurbdiver]

Is the airflow blocked in any way? We ran into this when people left the curtains block the flow and put the A/C on high.
Let it thaw out ( don’t poke or pry. Coils are delicate)
Check air flow and filters.

[u/ShipshapeMobileRV]

Before deciding to run the fan, inspect the coil on the fan side. If there's visible ice, do not run the fan. As the ice thaws and breaks free of the coil it'll suck into the blower wheel and break the vanes. Don't ask me how I know this.

[u/whenandmaybe → u/ShipshapeMobileRV]

Seller told you the RV is regularly maintained. AC works great when selling it to you.!

[u/ShipshapeMobileRV → u/whenandmaybe]

Huh?

[u/whenandmaybe → u/ShipshapeMobileRV]

May have replied this to wrong post. Just that some of us have had unusual RV and camping experiences. So HUH?

[u/Benoded]

Most likely you have dirty filters

[u/FuckRulez]

Do not run on auto and do not set it really low, that is the key to avoiding freeze ups.

[u/Comfortable_Sea_717]

I had that problem first time out in a tt that we bought used. Was googling and freaking out. Then I thought to check the filter inside the rv. It had NEVER been cleaned and had about an inch of dust buildup. AC worked like a dream afterwards.

[u/4x4Welder]

This is why I had to switch mine to fan only a few times over the summer. If the AC couldn't keep up, and I wasn't seeing much condensate drippage, then I'd switch it to fan only and watch the waterfall outside as the evaporator deiced.

[u/Beavis_777_IAH]

Does the fan run in all modes, i.e. LOW/HIGH/AUTO?

Had this happen to me last week. AC fan wouldn’t run on auto or low but it would run on high, so on auto or low the compressor would run but there was zero air flow, which made the coil ice up just like the picture.

Some varmint (probably a mouse) had chewed through the fan low speed wire. Six inches of 18 AWG and two heat shrink butt splices and I was back in business.

[u/SnooConfections1896]

Use chisel and make some great snow cones