Why would bed ac suddenly make lr ac finally turn cold??

[gowestwardho]

Here's one that makes no sense to me.



SCENARIO: when on anything less than 50A or Generator our 2017 31UL living room AC just blows "luke-cold" air (as opposed to "luke-warm" - you get the idea).



It's 98 degrees here outside San Diego and I've had the LR AC on Max Cold for 4 hours while we left for ice cream and AC. Just came back and coach is only a few degrees less than the outside air - absolutely horribly stuffy and hot (Important Note: we are stuck on only 30A here).


So just now, out of frustration, I decided to take a chance on running both AC's on 30A, and when I turn the Bed AC to max cold, suddenly the LR AC goes super cold!!!


They are two totally separate AC units and duct-works - why would adding another load like a second AC running make the LR AC go cold?? When I get home I'll add this to the list of usual suspects for my Dealer to sort out, but I thought it odd enough to see if any of you have any insights?


Don't get me wrong - the wife's not complaining - but this is too weird - even for a Jayco!


:-)

[Grumpy]

Did you have the front fan on "low" which caused it to freeze up? As soon as you turned on rear air, more air flow and living room coil defrosted.

[gowestwardho]

No, front AC was on "COOL HIGH AUTO". Put bed AC on same setting and almost instantly the front AC went to cold. I just now (in checking those setting to make this reply) turned off the bed AC and the front AC is remaining cold. Also of note is there wouldn't have been enough time for anything to "defrost" as this was more-or-less an instantaneous change in the font AC temp. I'm just hoping it remains this way until we get home (but we've been putting up with this for months now so it's high time to have the Dealer solve this mystery once and for all).

[hawkster]

No answer here but my 2016 31ul ducting is connected front and back. I often run the front ac at night and open br vents and close lr vents.

[Screwby]

As said above, are you sure they aren’t ducted together? Most front and rear air units share ducting, that way you can use either or both to keep unit cool depending on need.

[tsmatx]

In my 2017 Precept 31UL the ceiling ducts in the bedroom and front room are connected together. If you run both units the amount of cooled air will increase in both areas as long as the vents are open. Also, I would be wary of running both units on a 30amp connection. The load of 2 A/C units at 30amps may cause a low voltage to both units and could damage the compressors. I would run the generator just to be sure there is adequate power available for the 2 units.

[HJ Rosch]

The front and rear A/C units are ducted together so your front unit may not be working and when you run the rear with the front you are feeling cold air from the rear unit. I like the fact they are ducted together as I will run both to get the coach cooled down quickly and then the rear when we are in the front and front when in the bedroom so it is much quieter. I recently had to have my front unit replaced (under warranty) as it quit cooling after 3,000 miles and limited use.

[wags999]

Having both AC "on" may not of allowed either to get the required amerage.. By switching the one to high, it may of cut that unit off totally, allowing the other unit to get proper amperage. If you camp with 30 amp only you may want to get a dual plug adapter where you can plug into a 30 amp and a 20 amp outlet on the pedestal. That would allow you to run both AC (and not much else).

Good Luck.

[nalasha79]

Just an observation from mine. I was cooling the RV with both AC units and noticed the front (LR) was warmer than I thought I set it to. I checked and sure enough, I set it to a cool enough temp for it to be cooler than it was blowing. Then I thought it may be malfunctioning, but I went ahead and lowered the target temp and the cool air flowed from the LR. I realized that the bedroom temp was flowing out into the hallway and being measured by the front thermostat thus triggering the front AC to stop running and just run the fan. Silly but was the problem for me... We just have to remember that when we run both; set the LR cooler.

[t18skyguy]

You might pull the plastic off the the inside of the AC units. There is a piece of styrofoam that hangs down vertically to separate the intake and output. There was some trouble with that foam piece becoming dislodged and recirculating the cold air when it shouldn't. I reinforced mine with some 2 inch wide aluminum tape.
The two air conditioners are ducted together, but you need to close the two slider vents on each unit to get maximum effect for the ducts. The way it works (at least on my Greyhawk) is one air conditioner serves the whole unit on ducts, and adding the second AC just doubles the volume of both of them. At first I thought they would be front does front and back does back, but when on the ducts it's different.
I don't know if you have two 11,500 btu units, but if so, you can run them both easily and stay well under 30 amps. On my Greyhawk I think was 19 amps total with them both running.