Air to Water Conversion - Pioneer Mini-split

oharkins · 06-16-22, 01:56 PM

I have been using pioneer mini-splits for a while now and would like to convert one from Air to Air to air to water, the plumbing seems to be quite standard however I would like to override the control line and be able to tell the system to run or stop based on the demand at the heat exchange. Do these systems use a standard or is it a proprietary communication left up to the manufacturers? Has anyone attempted to "hack" the com line to establish the protocol?

Elcam84 · 06-21-22, 04:37 PM

Someone hacked it several years ago for an older import version but I don't have the link or remember what unit it was. I tried to find some info on it myself because I have a brand new 18K condenser for a Pridiom/Amcorair system but since they are not in business I cannot buy an inside unit. I would assume these Chinese ones all use the same communication but I don't have the guts to buy a damaged 18K evap unit and give it a try and hope it talks to each other.

AZheatpumper · 06-24-22, 12:04 AM

Here is what you get when you try. The only useable pieces of the mini split were the housing and coil.
If you had an indoor unit you could just swap the indoor coil with a water cooled coil and a pump.

But since you don’t and the outdoor fan motor and compressor are BLDC motors that require specialized computer algorithms to drive, and a stepper motor controlling a valves to meter flow, you’ll have to scrap pretty much the entire thing and replace it with single phase conventional hardware.

There is no jumper or way to make that outdoor unit pcb do anything without the indoor unit as far as I know.

Elcam84 · 07-06-22, 07:58 PM

After some searching I found one of the older sites. The older Mitsubishi units used a seperate communication line and communicated via serial. So not hard to do if you know how to. Not a clue how the current mitsubishi is.

The import ones all communicate on one of the 240v hot wires. IE if you hook it up and the head unit doesn't see the condenser then you flip the wires between the units and it will work.
But being that they piggy back on a 120V AC line it can't be that complicated. The question is have they changed the communication protocol. I would doubt they have as with products from there if it works they don't change it.

All the motor control is in the powersupply of the unit it just needs to be told what to do. Most likely it's done in steps dictated by the inside unit control. They aren't going to overcomplicate it.

06-16-22, 01:56 PM	#1
oharkins Lurking Renovator Join Date: Nov 2021 Location: Montana Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	Air to Water Conversion - Pioneer Mini-split I have been using pioneer mini-splits for a while now and would like to convert one from Air to Air to air to water, the plumbing seems to be quite standard however I would like to override the control line and be able to tell the system to run or stop based on the demand at the heat exchange. Do these systems use a standard or is it a proprietary communication left up to the manufacturers? Has anyone attempted to "hack" the com line to establish the protocol?

06-24-22, 12:04 AM	#3
AZheatpumper Lurking Renovator Join Date: May 2022 Location: Buckeye Arizona Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	Here is what you get when you try. The only useable pieces of the mini split were the housing and coil. If you had an indoor unit you could just swap the indoor coil with a water cooled coil and a pump. But since you don’t and the outdoor fan motor and compressor are BLDC motors that require specialized computer algorithms to drive, and a stepper motor controlling a valves to meter flow, you’ll have to scrap pretty much the entire thing and replace it with single phase conventional hardware. There is no jumper or way to make that outdoor unit pcb do anything without the indoor unit as far as I know. Attached Thumbnails

06-21-22, 04:37 PM	#2
Elcam84 Apprentice EcoRenovator Join Date: Jun 2013 Location: TX Posts: 275 Thanks: 2 Thanked 31 Times in 24 Posts	Someone hacked it several years ago for an older import version but I don't have the link or remember what unit it was. I tried to find some info on it myself because I have a brand new 18K condenser for a Pridiom/Amcorair system but since they are not in business I cannot buy an inside unit. I would assume these Chinese ones all use the same communication but I don't have the guts to buy a damaged 18K evap unit and give it a try and hope it talks to each other.

07-06-22, 07:58 PM	#4
Elcam84 Apprentice EcoRenovator Join Date: Jun 2013 Location: TX Posts: 275 Thanks: 2 Thanked 31 Times in 24 Posts	After some searching I found one of the older sites. The older Mitsubishi units used a seperate communication line and communicated via serial. So not hard to do if you know how to. Not a clue how the current mitsubishi is. The import ones all communicate on one of the 240v hot wires. IE if you hook it up and the head unit doesn't see the condenser then you flip the wires between the units and it will work. But being that they piggy back on a 120V AC line it can't be that complicated. The question is have they changed the communication protocol. I would doubt they have as with products from there if it works they don't change it. All the motor control is in the powersupply of the unit it just needs to be told what to do. Most likely it's done in steps dictated by the inside unit control. They aren't going to overcomplicate it.