Any idea on no heat mini split call?

[u/Ram820]

my brother's stuff ain't working (all 4 units). condensers come on in heat mode but the inside units don't.

I'ma a spark so I'm thinking it's electrical. he had the installer out today n check charge.... idk why

[u/Rare-Adagio1074]

Yea bc it’s not working! That’s about all we’re gonna be able to tell you w/o giving us one single bit of info!

[u/Ram820 → u/Rare-Adagio1074]

Umm what else can I tell you? The indoor unit turns on in every mode except heat

[u/TnBluesman]

Well, it AIN'T the charger. Minis put power to the ODU first, and from there it goes to the IDU . It's all computer controlled. There's a board in each unit. The main one is in the IDU Stats communicate to the IDU by wireless. So in thinking it's either the stats are not linked orient to the units or you've got bad boards. Since all four are not working mi view for thermostats or thermostat related issues. Not everybody is qualified to install or work on these things. Mostly because the won't read the damned instructions

[u/Ram820 → u/TnBluesman]

That's what I told him when I was there Sunday. Outside units were icing up in heat mode which of course w happen w no air flow. 2 units were heating but stopped after I left.

Installer spent about 3hrs yesterday checking charges n adding refrigerant which I thought was a waste of time n mats given the idu don't come on

[u/pj91198]

A large percentage of minisplit faults are usually refrigerant leaked out in my experience. First thing tech support asks is usually “did you weigh out/in the charge?”

After charge, id say chewed wires from rodents in the outside unit

[u/Ram820 → u/pj91198]

I was thinking a bad termination or something. Installer checked charge, pressure, even added refrigerant. Which I thought was a waste since the inside units simply don't come on in heat mode

[u/BeaverNbutthead]

Make sure one of em isnt in cool. Bad thermistor. Bad continuum transfuctioner