AC Fan Slowing Down

270FVFamily

Hello all, this is our first year with a 2004 270 FV, we love it and all systems seem to work fine and our AC was great until last weekend.  Water is running through it fine, but after a couple of hours running the fan (on Auto or manual fan speeds) slows to a trickle of airflow coming out of the vent, not nearly enough to cool off the cabin.  I have to put my hand right up to the vent to even feel anything coming out.

I checked the intake vent and the filter seems fine, there is a white plastic wall behind that which is very very cold.  I have a feeling maybe the fan is bad?  What is that wall? Except once it's been off for a few hours it will run ok again until it slows down again like before.  Anyone had this problem or know what to check?  Is there a way to blow a fan through there to see if that's the problem?

Thanks ahead of time!

raybo3

Next time this happens check the unit and see if its frozen. My guess is your unit is turning into a block of ice. Check it out and keep us posted. Also welcome to the RBOC.

Black_Diamond

The unit is freezing up, so zero air flo. You can adjust the programming to prevent this. There are several threads on here about that or look up your controller instructions. For short term: turn it off to melt.

270FVFamily

Thanks Raybo, I think you're right, whatever that wall is behind the air return seems like a solid wall of ice.  I suspect it may be freezing up because the fan is slowing down so much. Or, is it slowing down bc the unit is freezing up and no air can get through?   

Bruce

If the unit is indeed freezing, that can be cause from low airflow past the evaporator, which is usually the result of a dirty/clogged air filter or a dirty/clogged evaporator itself. If that is not the case (as strage as this may sound) it can be caused by the system being low on freon.

  Hope this helps, and good luck.

TikiHut2

I found the return air duct laying loose in the bilge under our aft bunk. If it's low air flow it may need to be re-taped back onto the register or even at the a/c unit. As you can imagine, it made a world of difference in the cabin rather than just cooling the bilge bugs.

Mike

Babyboomer

My fan went bad a few years back was made in Italy took 2 weeks to get it easy fix just the wait went through a Local Marine AC guy to order had to pull the fan and give all numbers on the unit. Also the filter is on the inside f the unit like looking at it it' facing the hull. Now I duct tape a regular furnace filter to the inside of the return grate wall that grate is screwed to is easily removed.

270FVFamily

Hello all and thank you for your answers. After messing with this a bit it is absolute that the cold white wall behind the intake vent is indeed the evaporator (looks like a radiator?), with no airflow it had turned to solid ice!

I'm going to guess it's not too low on freon? Where I'm at is a beautiful clear lake, and no Marine AC guys at all. Matter of fact we're one of the few cruisers on the lake at all, the only boats bigger than us are houseboats, lol.  Here's our newest cove:

LOVE OUR RINKER!

Anyway, I'm handy but kinda on my own to diagnose and no tools of the trade so to speak.

However, I believe Babyboomer may be onto something with the bad fan.  Works like a champ at first, for about an hour or two.  I'm guessing again, that the fan is slowing down after it gets heated up for awhile and the evaporator freezes, making it even worse.  With the summer heat coming on I'd like to figure it out. I've got a small electric fan that fits perfect in front of the intake vent, so I'm just going to turn it on next and see what happens.  That should at least tell me if its a fan issue?

 

 

 

270FVFamily

Yes RinkerYan, when first switched on it blows plenty of nice cool air into the cabin, there's only one outlet vent under the stairs.

Weber

Try just running the fan for an hour, with the ac off.  This will tell you if the blower is going of on overload, going bad in general, or if there is another problem.

If the fan continues to run just fine, then you have an airflow problem or refrigerant problem.

Check your filter and your return duct.

270FVFamily

Didn't try just the fan Weber, although I should, that's a good diagnostic idea.  For the 4th our family of 5 stayed on the boat 5 days and I had just hooked up a small 10" square box fan in front of the intake vent and the AC ran all night just fine.  I have a feeling I'll be replacing the fan unit.

We watched 3 different fireworks shows in different cities on the lake each night, never watched those on the water before, was really cool. 90 miles we traveled!

 

 

 

 

raybo3

That is awesome. I love seeing the fireworks from the boat.........

270FVFamily

I know this is an old thread but just thought I'd update in case anyone else ran into this, the problem with the AC unit freezing up was as simple as I had it turned down too cold.  I had it the temp down as far as it would go and the unit wouldn't get the chance to cycle.  Basically it just has to shut off for a bit to warm the condenser a little.  I keep it on 73 or 74 now, the cabin is really comfortable and the unit runs when it should.  This was my first boat with AC and I'm guessing was just a newbie thing. Yay

rasbury

Hey, it's always a nice surprise to find it's something simple....

DanD2

Humidity plays a huge role here. The more humid it is, the bigger chance of things icing up.

Dream_Inn

You can also set it so it reverse cycles once an hour for whatever duration you set.  then you can set it at 65 and not worry.