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Daikin mini-split 6 degree off only in heat mode (AC mode s fine)

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#24 ·
This is not a Daikin problem. This is an application issue and also a lack of education from your installing dealer. They should have made you aware of the limitations of what you want to do.

The outdoor unit is oversized, the indoors are installed too low, and Auto mode does not work well for comfort conditioning applications. All this is taught in every training class from all manufacturers. Your dealer needs to make this right.
 
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Discussion starter · #25 ·
I'm hoping there are other folks who have experienced the same issue (besides the one I already pointed out)...

Accepting it like it is is not an option since I need auto mode to work!
 
Discussion starter · #27 ·
If 4' is low for the head, does that imply if I simply move it 2 feet up it'll correct a 6 degree offset problem?

What about AC mode...under those same conditions, I would expect it to have a problem too, but it is perfect!
 
Discussion starter · #31 ·
Yes...

It problem is only in heat mode, in AC mode it cools both rooms very closely to the setpoint with no issues (well within less than 2 degrees!)

This is what I don't understand!! (If it was simply an offset problem in both modes, that would be easy to understand!!)
 
Discussion starter · #33 ·
Yes both are in heat mode...otherwise it does nothing! (which is totally understandable!)

It also does the same thing if I only run either one of them by themselves....
 
Discussion starter · #35 ·
I'm not sure how they sized it but I can tell you that it is somewhat oversized but in cooling mode it needs to remove the heat from the entire roof while in heat mode if has an easy time being on the second floor (Cape Cod).

So while it's a bit oversized in heat mode in cooling mode it's a blessing...

The thing about this problem is it maintains exactly a 6 degree offset no matter how cold it is outside. If there were a sizing issue the magnitude of the problem would likely change as well!

This seems like a control issue straight up. To me all the worry about the thing needing to be 2' higher is the same as saying that there is that much of a temperature gradient in the room.

That also falls apart when there is air moving in the room (such as a ceiling fan running).

The other thing about the sizing issue is it runs just the same with a window open...if it was a sizing issue the problem should go away right there!
 
#37 ·
Your issue is the oversizing. The outdoor section can only ramp down so much then it diverts the extra hot gas to the unused head! That head slows the fan, but it still adds heat to the room.

It's a bad install (too low) and oversize combination not a Stupid Controls issue!
 
Discussion starter · #38 ·
If I open a window that is the same as a larger room...it still behaves the same under those conditions.

That cannot be the only cause. The problem would also not remain fixed at 6 degrees off over the range of outdoor temperatures it has seen so far.

If I'm wrong thinking this I would love to get straightened out!

Thanks!
 
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Mott Rettop
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