A/C freezing and not cooling

[AIM15RB]

I just received delivery of a 2024 Grand Design Imagine AIM 15RB travel trailer. The Furrion AC unit has the following configuration:

Roof Top A/C Unit: 13,500 BTU (model # FACR13HESA); and
Air Distribution Box: model # FACT11CA-PS.

No matter what settings I use on the air distribution box control dials, and in every possible combination, the results are the same … my evaporator coil freezes up. This is a brand-new unit installed at the factory … I have done all of the basic trouble shooting – examine the filter and looked for blockages or problems with both system coils.

Upon inspection I found that the room sensor [bare copper wire in the picture](I think that what it is – I could be wrong) was merely shoved up into the unit – not touching the coil. MORE importantly, I found the freeze sensor NOT wired up. I repositioned the room sensor thru my filter pointed toward the front of the house - with no results.

The evaporator coil is freezing and the coach has never been cooler than the high-eighties. I live in eastern Virginia near the Chesapeake Bay.

Any thoughts on what’s going on.

Steve

[howson]

AIM15RB

Either the freeze thermistor is not installed correctly, air flow is not correct, or the unit is low on refrigerant.

If low on refrigerant the only fix is a replacement.

https://gdrvowners.com/forum/operati...a-c-be-located

https://gdrvowners.com/forum/operati...r-a-c-freezing

https://gdrvowners.com/forum/operati...re-freezing-up

Howard

[AIM15RB]

AIM15RB

Either the freeze thermistor is not installed correctly, air flow is not correct, or the unit is low on refrigerant.

If low on refrigerant the only fix is a replacement.

https://gdrvowners.com/forum/operati...a-c-be-located

https://gdrvowners.com/forum/operati...r-a-c-freezing

https://gdrvowners.com/forum/operati...re-freezing-up

Howard

Thank you Howard… I also looked at the other threads… That’s what I thought might be the problem but being a first time RV owner and inexperienced with these systems, I figured I’d put out a post… plan is to take it back to General RV - my dealer where I took delivery - and have them confirm the low Freon issue and replace it - Thank you again. – Steve.

[AIM15RB]

AIM15RB

Either the freeze thermistor is not installed correctly, air flow is not correct, or the unit is low on refrigerant.

If low on refrigerant the only fix is a replacement.

https://gdrvowners.com/forum/operati...a-c-be-located

https://gdrvowners.com/forum/operati...r-a-c-freezing

https://gdrvowners.com/forum/operati...re-freezing-up

Howard

Sorry, Harold, I almost forgot…

1) Can you tell me what the bare copper wire clad in a clear plastic tube is?

2) can you tell me why I freeze sensor isn’t wired into my unit?

[howson]

AIM15RB

Not sure what is meant by "bare copper wire clad in a clear plastic tube". Can you take a picture and specifically explain where this component is located?

For #2 -- fairly certain that sensor is there, just need to find it.



Howard

[AIM15RB]

AIM15RB

Not sure what is meant by "bare copper wire clad in a clear plastic tube". Can you take a picture and specifically explain where this component is located?

For #2 -- fairly certain that sensor is there, just need to find it.

Howard

Hi again, Howard… Pictures are at the top of this post… The copper wire is clad in plastic and was just pushed up into the unit not touching the coil. The freeze sensor is also in the picture and you can see it’s just a plastic clip squeezed into the evaporator coil fins - so my questions remain - if you’d be so kind

[howson]

AIM15RB -- sorry, I can't see the sensor in your pic. If you know it's there I'm not quite following this conversation since it's stated in post 4 that a freeze thermistor was not wired into your unit???

Regardless, one more shot at answering your questions.

For that copper piece...it's a capillary tube thermostat for units that have the controls built into the plenum (dial in the ceiling). The capillary tube is not used if you have a wall thermostat.




I also found in the video where the freeze sensor is supposed to be installed in the evaporator coil. 1/3 to half way up, left of center according to the video.



Howard

Edit: I see the sensor in your pic now--the little blue piece.

[AIM15RB]

I see the sensor in your pic now--the little blue piece.

Howard you’re the best… So that copper wire clad in plastic is what I thought it might be and as you described it “ a capillary tube thermostat” … That makes sense because the AC unit did improve but only slightly when I pulled it away from the evaporator coil and pulled it out into the coach - and no I do not have a wall thermostat.

Now on to the freeze sensor… What you see in the picture is just the blue clip. My understanding is that there’s supposed to be a wire with some type of sensor inserted into the blue clip. The blue clip gets inserted into the coil fins with the sensor getting on or near the coil…

So my question is why would I have a freeze sensor plastic clip (the blue plastic piece you can see in the picture) and not have it wired up with a freeze sensor on it ??? Seems like an issue to me – what do you think?

And by the way, thank you so much for your time and your experience. Any replies – Steve.

[howson]

So my question is why would I have a freeze sensor plastic clip (the blue plastic piece you can see in the picture) and not have it wired up with a freeze sensor on it ??? Seems like an issue to me – what do you think?

Steve,
I think the sensor is somewhere up in the ceiling. It just fell out of the blue clip.

Trace all the wires coming out of the control box--one of them (as shown in post 5) is the sensor. The sensor is then inserted into the blue clip which is what holds the sensor in place against the evaporator.

And by the way, thank you so much for your time and your experience.

You're welcome! Your questions shook out some of the cobwebs on the Furrion--been awhile since I took Lippert's online course.

Howard

[AIM15RB]

Steve,
I think the sensor is somewhere up in the ceiling. It just fell out of the blue clip.

Trace all the wires coming out of the control box--one of them (as shown in post 5) is the sensor. The sensor is then inserted into the blue clip which is what holds the sensor in place against the evaporator.

Howard

UPDATE:
Howard I searched everywhere for that freeze sensor– not in the ceiling not – not in control box – not in the unit on the roof pulled the cover searched around there.

I have no wall-mounted thermostat and my air distribution box merely has two dial controls … one is called temperature control, and one is called operation control [Either “optional” heat - AC or fan. The only other thing coming out of control box is that copper wire, clad in plastic (shown in the picture at the top of the post) which you suggested was a “capillary tube thermostat”.

This AC unit has its own dedicated 120 V power supply, and I believe the harness is part of the Lippert “OneControl” system. Although OneControl does not operate or manage the AC at all.

last question:

Is it at all possible that this particular Grand Design RV [Imagine AIM 15RB] does not have a freeze sensor as part of the AC package:

Roof Top A/C Unit:
1) 13,500 BTU (model # FACR13HESA); and
2) Air Distribution Box: model # FACT11CA-PS.

My service appointment is pending with the dealer who sold me the unit but I need to know about this free sensor … Not only do I believe the unit, also as you suggested, is low on refrigerant, but I need to know what else should be there and isn’t - thanks - Steve

[howson]

Is it at all possible that this particular Grand Design RV [Imagine AIM 15RB] does not have a freeze sensor as part of the AC package

Wow--I guess it's possible but that's a first (for me), Steve. A freeze sensor is an integral component to all the RV air conditioners I've personally worked (and trained) on.

Please take another picture (or two) of the control box so I can see all the wires coming out of it. I'd like to compare against the Furrion seminar documentation.

Howard

P.S. I'm on the road and out and about, so forgive the slow responses.

[AIM15RB]

Wow--I guess it's possible but that's a first (for me), Steve. A freeze sensor is an integral component to all the RV air conditioners I've personally worked (and trained) on.

Please take another picture (or two) of the control box so I can see all the wires coming out of it. I'd like to compare against the Furrion seminar documentation.

Howard

P.S. I'm on the road and out and about, so forgive the slow responses.[/QUOTE]

Hello my buddy Howard… No worries about slow responses… Here are the pictures you asked for:

[howson]

AIM15RB

Thanks for those pics, Steve. Collection of random thoughts below.

The control box in the manual Air Distribution Box (ADB) is not in the training material with specific information like the electronic ADB's control box.

etrailer has a review of the ADB that shows the control box. It's not very informative, but here's a link: https://www.etrailer.com/tv-Demo-Fur...CT11MA-PS.aspx

The one item that caught my attention was the installation manual for the ADB referenced in the video. Unfortunately I can't find a digital copy online. There's a brochure (linked off of etrailer's site) but not the installation manual. There's also a bewildering collection of manuals on Lippert's support site, but I couldn't find the one specific to your installation. See https://support.lci1.com/air-conditioning

What I did find interesting on etrailer's site is the multiple complaints of freezing in the reviews of the ADB. No fix was mentioned in any of the posts, but for reference see them (bottom of page on etrailer) here: https://www.etrailer.com/Accessories...CT11MA-PS.html

An updated Furrion training handout was found here: https://lci-support-doc.s3.amazonaws...t-hand-out.pdf Look closely at slides 31 and 32 (on page 16) and compare against the installation in your Imagine. If either one isn't right it could cause the problem.

Finally, if you have a clamp-on multimeter that measures 120vAC amperage (and you know how to safely use it) there's a way to check the compressor's operation without climbing on the roof and taking off the shroud. By measuring the amp draw during operation the amp value can be compared against the compressor's known specifications. If they are close (outside temperature plays a role) low refrigerant can be either proven (amp draw with compressor running will be low) or removed as a suspect.

If measuring the amp draw is within your capabilities (you'll have to work with live 120vAC) and you have a clamp on multimeter, reply and I'll post more info.

Howard

P.S. Lippert (who owns Furrion) is your best resource at this point to explain the lack of a freeze sensor (and what performs the sensor's function in the manual ADB configuration). Lippert's customer service info is here: https://support.lci1.com/contact

[Jlawles2]

Steve, can you follow the molex connector that goes UP out of the switch box? Flipping through the manual Howard sent it appears the is a junction box (the one you show) and a controller box. The controller is where the freeze sensor would be located.

[AIM15RB]

[QUOTE=Jlawles2;n118441]Steve, can you follow the molex connector that goes UP out of the switch box? Flipping through the manual Howard sent it appears the is a junction box (the one you show) and a controller box. The controller is where the freeze sensor would be located.

Hello Jlawles … see the picture above talking about the control box and its electrical connections and the freeze sensor being present … what you’re calling a switch box is the controller. If what you’re saying is, there’s a junction box on the roof under the AC shroud - yes I saw it and did not remove it to open it up … if what you’re saying is that the freeze sensor could be rolled up inside it - I could check - it’s the only other place it could be … if you think getting up on the roof and once again, removing the shroud and opening up that junction box there’s a place where a free sensor could be. I could try that.

so just to be clear the pictures you reference of mine above are the control box with no freeze sensor in it. If you think it would be worth opening up the junction box on the roof -please let me know.