A/C Freezing Up

[Campingfamco]

Hi Everyone,

We’ve been out a few times now with our new 2021 Whitehawk 24MBH.

On this most recent trip we’ve noticed our AC is having issues. Here are the conditions:

- ambient temp ranges from 60-75 degrees but the sun heats the trailer up very quickly even with all the shades closed.
- we have tried running the AC set at 70-74
- fan on both low and high
- dump closed and open

I’ve checked the filter and the tape work to make sure things are sealed, but it’s pretty clear the unit freezes over and I have to shut it off and run the fan trying to unfreeze it.

I think part of the problem is when we use our ducts instead of the dump it freezes more. So I’m trying to leave the fan on high and the dump wide open to increase airflow over the system. It’s just pretty loud that way but I guess that’s what it might take.

I’m looking for debris and to make sure I had a good seal, I noticed the power box mounted in the middle of the return. It didn’t just fall in the position, there is a screw mounting it there. Could this be what’s causing our problems or is it the unit doesn’t have enough airflow unless the dump is wide open?

Thanks

[RoadrunnerII]

That's just not right
I would move it asap! Bet the AC will work much better. Get it out of the airflow completely if possible

RoadrunnerII

[TxLoser]

Seriously…. That’s the most ridiculous thing I’ve seen so far from the factory.

[Grumpy]

The control box is supposed to be laying flat...so that may be causing enough air disruption to cause the issue.

Here is a you-tube showing it.

https://www.youtube.com/watch?v=jW-hrR-d80Y

[16WhiteColly]

That is NOT correct at all.

[Campingfamco]

So this confuses me. The video shows the box mounted flat and I do see the bracket where it should be mounted. I would think that would limit airflow though. Am I missing something? Also, the unit seems to be blowing really really cold air and pretty hard for the most part. Is there another reason why it wouldn’t cool the unit enough? I had a roo with three tip out beds on it and that AC would cool it just fine on a 90 degree day. It was only in the 70-80’s. Is it the sun heating up the exterior because it’s painted gray and not white?

[craigav]

I would install the box like in the video. While not a lot, it appears that the electrical box would have less surface area (blockage) when more of it rests on the shelf that is already blocking some flow.

I had a thought to share. Most, if not all Dometic (and others) A/C's have a freeze sensor that is normally attached to the cooling coils (evaporator). What is supposed to happen is that when the coils get cold enough to start freezing then the freeze sensor connected to the control board will simply turn off the compressor for a few minutes leaving the blower fan running and then turn the compressor back on once the coil temp rises. This is supposed to keep the A/C from freezing up.

My thought is that it is possible that the freeze sensor has fallen off the coils in your A/C, perhaps it was pulled off by pulling on the wire to the sensor when the A/C was installed. I highly suggest that you check to make sure it on the coils. Here is a link to some instructions, although I don't know that this is the correct sensor for yours, the link is just an FYI to know where to find the sensor (you may can find better instructions if needed). ~CA http://techsupport.pdxrvwholesale.co...309226.003.pdf

[Campingfamco]

I just remounted the box the way the video shows. I also checked the freeze sensor hasn’t fallen off and is connected. It looked to be good to go and solid on the coils. I don’t have 30 amp at the house I can plug into so running the AC off the wall outlet won’t work. I did run the fan and didn’t notice a huge difference, so I’ll test it out in a few weeks when we go camping again. Thanks for all the help!