Gree Mini-split not starting

[Danuaro]

I've got a two head Gree mini-split installed by the previous owners of our place. Recently one of the indoor units has decided not to function. It will turn on, however it seems to not send a signal to the outdoor unit to switch it on. So the indoor unit display comes on, the duct swings open, and then nothing ever happens. When you change modes that seems to work, and the other inside unit hooked up to the same outdoor unit works just fine, so I don't think there is a problem with the outdoor unit itself, just the communications connection between them.

The one other odd behavior is that when you change the temperature on the remote, the display on the remote changes, but the head unit display does not change. Again, when you change modes, that switches on both displays and actually works. See the picture to explain that.

The gree manual has some troubleshooting flowcharts, but they don't seem to exactly help, and the unit has never thrown an error code. Here is the link for that anyway.

https://www.greecomfort.com/assets/our-products/vireo-plus/documents/vireo-plus-service-manual-18k-and-24k-b.pdf

Thanks for any suggestions

 

[fitter30]

Did u try using another units remote? I've got 2 gibson minis that gree made them. Wall unit has a aux button right hand font side manual said to push it for cooling can try it. Removing top of the condenser is the main board has all the fault codes and a flashing light on the board. Don't remember if it has any for the indoor units but there are many. Have u powered down the condenser and restarted it? Check the fault code first.

 

[Danuaro]

Thanks for the reply! I've tried the other remote and seem to get the same issues. Hitting that aux button also doesn't seem to do much, so I don't think it is a remote issue. I've also tripped the breaker and left it off to see if anything reset to no avail. There have also been no fault codes displayed on the indoor unit. This afternoon I swapped the control boards and temperature sensors on the indoor units and that didn't seem to do anything either, so I don't think the problem is inside.

I pulled the side cover off the outdoor unit and swapped the wiring of the two units so that the broken unit was hooked up to the good units power supply. That seemed to immediately correct the issue, however as the refrigerant lines weren't swapped I didn't leave it on as I didn't know if that would cause some sort of issue. So I think you are on the right track to check out the outdoor units main board and fault codes. Unfortunately it got a little dark and cold, so that will have to wait until tomorrow!

 

[PoorUB]

Sounds like the board in the outdoor unit.

For shits and giggles I might try cross wire the other indoor to the defective side of the outdoor unit and see what happens. If nothing works then it definitely is something in the outdoor unit. If it works, reconnect every thing properly and try it, perhaps it was a loose connection.

Check wiring between the connections and the control board. Beyond that it is probably the board. Good luck getting a board, you might have to find a Gree dealer. It will not be cheap. The electronics in any brand on mini split is ridiculous, like $1,000 ridiculous.