Mini split issues

[huggi]

Hello garage mates, I've been insulating and installing a mini split in my pole barn. See pics attached. I bought a mini split off Facebook marketplace that was mismatched, outside unit 18k btu, inside unit 24k btu both by LG. The seller said it should work, long story short they will not work together getting error ch51 meaning mismatch between units.

My question is, when changing the inside unit to the correct 18k btu I will have to disconnect the lines, though I cannot get the r410a to pump down into the outside unit (because it won't run). Any suggestions what to do here?

Thanks

 

[rlitman]

Call an HVAC tech with the machine to extract the refrigerant.

 

[PoorUB]

Yep, you need to hire someone to pull the R410.

Are you certain you can buy a matching unit? If it is more than a couple years old you might not be able to buy a unit. These mini splits change frequently and matching the indoor and outdoor units might work back a couple years at best, so be careful or you will end up with three units that will not work together!

I sold Panasonic and Gree and is was scary how often there was a change so units would not interchange.

Oh, and never believe what a seller off eBay, FB Marketplace or Craig's List tells you!

 

[Terry D]

I'm not 100 percent sure, but I don't think all or some mini splits can be pumped down due to the fact that the electronic expansion valves are out in the condenser. As said, you would need to reclaim the refrigerant and weigh in a new charge. Probably impossible, but I would try to get your money back on what you bought and get a matched set. Defiantly get ahold of the manufacture and see what indoor units are compatible, if any.

 

[fitter30]

Rotory compressor i wouldn't pump down their clearance is to close chance it would over heat. Reclaim the refrigerate. Plus the condenser on high efficiency condensers don't hold very much being a micro channel.

 

[Phuckin' Jim]

Since you're this far into it, and the units are already installed, you COULD buy a control board for the compatible 18,000 btu indoor unit and install it into the 24,000 indoor unit you already have installed.
The 18k btu board likely wouldn't "care" that it's running the fan of a 24k btu indoor unit.
I would think that the temperature sensors would also have the same specs.

I'm not necessarily saying YOU should do that, but that's what I would be tempted to try if it were my own.....

 

[PoorUB]

Since you're this far into it, and the units are already installed, you COULD buy a control board for the compatible 18,000 btu indoor unit and install it into the 24,000 indoor unit you already have installed.
The 18k btu board likely wouldn't "care" that it's running the fan of a 24k btu indoor unit.
I would think that the temperature sensors would also have the same specs.

I'm not necessarily saying YOU should do that, but that's what I would be tempted to try if it were my own.....

That is assuming all the sensors, motor and other controls in the unit jive with the "odd" control board. I would not chance it. Plus some of the boards are 3/4ths the price of the whole unit!

 

[justinjoyal]

Because it is not running, you will need a tech to recover the refrigerant.

Tip: Should've done your connections behind the wall unit instead of burying them in the wall btw (unless you put an access panel or something.) That way if something goes wrong you don't have to tear the wall apart.

 

[huggi]

Thanks for all the advice guys, the seller was able to match the units for me. I had an HVAC guy come out and recover the 410a and change the inside unit. Cost $450 (not cheap).

 

[Phuckin' Jim]

Glad it worked out in the end, even though it cost you $450.
Hopefully the cost of the system, plus the $450 ended up being cheaper than a complete new system.