MarineAir system is acting up....

WaveHog

I have a 2008 Rinker 350 with a MarineAir system.  The product number is 205-311740, model number VCD18K/1-HV. My control unit is running software A21.  Recently the unit has started not running because it will show a ambient temperature of something like 50 to 57 degrees, the actual temperature in the boat will be much higher.  For example, this morning it was 79 degrees in the boat and the desired temp setting was at 69 degrees but the ambient temp reading was 54 on the control panel.  Can you give me any ideas of what might be going on with the unit?  If I cut power completely to the unit and turn back on the ambient temp starts climbing and the unit will kick back on and cool the boat.  Any help would be great!

Liberty44140

Have you done a full reset of the digital control? The book instructs you on how.

WaveHog

No, I have not tried that, I'll look for the instructions in the book, thanks so much for the idea

Hamdog

WaveHog,

This is simply from my memory of reading posts on this site but I remember somebody having a similar issue and it was due to the ambient temp sensor being mounted too close to the actual ac air output so it was reading the temp of the cooled air and not ambient. Again, just from lurking on here. Somebody may read this and tag on.

JMGINWV342

If it is a passport I/O control, you may be able to go into the program mode and adjust the ambient temp.

Programmable Parameters Table Program Number Description Default Range
P-1 Operating Mode 0 0 = Auto 1 = Cool Only 2 = Heat Only
P-2 High Fan Speed Limit (arbitrary units) 95 65 - 95
P-3 Low Fan Speed Limit (arbitrary units) 55 30 - 64
P-4 Compressor Staging Time Delay 15 5 - 135 seconds
P-5 Temperature Sensor Calibration Ambient Temp Ambient 10° F

WaveHog

Thanks Hamdog and JMGINWV342 for sharing ideas.  I had previously tried adjusting the ambient temp, however, I am already at the high end of the 10 degree swing you are allowed so I have no room to move up which is what I need to do.  The sensor that Hamdog pointed out could be the cause for sure except that this is a new problem, the AC worked perfectly all summer last year and up until the last couple weeks this year.  Just to keep this updated I wanted to share the below info that I received directly from Dometic (I emailed them for ideas as well, great customer service by the way, they got back to me with in 24 hours).  I will update this thread once I solve the issues so that hopefully it helps someone else.  The email from Dometic reads: 

 It sounds like an air sensor has failed. It you don't have an alternate air sensor installed in the return air stream, then installing one usually takes care of the issue because it bypasses the display head sensor. 

If you do have an alternate air sensor installed, you can unplug it from the circuit board jack marked ALT AIR, and allow your system to run off of the display head sensor. 

jme097

You can calibrate the ambient sensor. The sensor is actually on the thermostat itself. It is a little black nub on the bottom of the stat. You can adjust it within 10 degrees. I had to do the same thing on my 280 this spring

WaveHog

Just an update, I found the issue.  The alternate air sensor was clipped to the pan that holds the condensation from the AC unit.  This water was obviously cold and was causing the air sensor to false read.  I unclipped and relocated the sensor to the return air flow area and now it is reading and running correctly.  It appear to me that this should have been done during install and was simply never handled at that time.  All is cool in the boat now (literally and figuratively).  Thanks again to all that helped!

Dream_Inn

Good find and thank you for reporting what you found.  I'm sure others will learn from this!

Hamdog

Good find!! I always like the ones that don't cost BOAT dollars. I guess I was close to right in my earlier post.

WaveHog

Thanks JMGINWV342, I do have the passport, I did try that option, you can only adjust 10 degrees and it was already at the top of the adjustment range (plus I had like 25 degrees to go).  Thanks to Hamdog as well.....I have no idea where that might be mounted but that crossed my mind as also, I will have to dig around this weekend and see if I can find that sensor......only thing making me think it is something else is that this is a new problem that has started over the last few weeks, it performed perfectly all last summer and the the beginning of this year, I'm in Arkansas so I have been using AC since March! 

scaliwagg

I have the same rinker with the same model of air system. Can anyone tell me if this model is for both air and heat, or just air?
Thanks

skennelly

Should be both.

scaliwagg

Actually turns out it is air only. Thanks though.

Handymans342

Must have been a Florida boat lol