Replacing ISY with Home Assistant – Part 1 – Preparation

This will hopefully be a short series on migrating away from my ancient ISY994.

They killed it!

I have had an ISY994 since early 2018, and it has served me well. It is the core communicator with my Insteon and Z-Wave devices. However, Universal Devices is killing it in favor of their eisy device.

Now, I have to be very clear: as a software engineer, I absolutely understand their decision. Innovating software while having to support old hardware is a painful process. However, the cost to move is making me look elsewhere.

When I originally purchased the ISY, I paid about $400 for the unit and the Serial PowerLinc Modem (PLM). Considering it has been running for 5 years, $80 a year is not bad at all. But to move to the eisy, I need to buy:

  • eisy – $290
  • Serial Adapter for my PLM – $26
  • Z-Matter USB – $126

So I am looking at about $450 for an upgrade. But some more “recent” developments make me wonder if I can do it better.

Enter Home Assistant

I do not have an exact date, but I have been running Home Assistant for a few years, and I prefer it over the ISY. The interface is newer, and the open source nature makes it a bit more reactive to new technology. Now, Home Assistant has an integration with the ISY, but the ISY’s APIs are, well, flaky. I find myself having to remove/re-add the ISY to Home Assistant, reboot the Home Assistant, and/or reboot the ISY to get it back.

With the ISY being retired, can I just replace it with the Home Assistant? Well, that’s what the prep work is about.

Requirements Gathering

Like any good project, I started by outlining some basic requirements:

  1. Insteon Support -> I have a lot of Insteon devices, mostly hardwired switches. Supporting those is non-negotiable. I have a Serial PLM, it would be nice to re-use that for communication with my Insteon devices.
  2. Z-Wave Support -> I have a few Z-Wave devices, mostly some plug-in outlets and a relay. These are currently supported via my ISY, but the antenna is weak and therefore the Z-Wave is less reliable.
  3. Standalone -> I am running Home Assistant as a Kubernetes node in my production cluster. Sure, it works, and it makes upgrades easier. Having a critical system in lab components makes me nervous, so I want to move Home Assistant to its own hardware.


Right now, I am in experimentation mode. I have ordered some parts to connect my PLM directly to a Raspberry Pi, and have started the process of installing Home Assistant on the Pi. I am also shopping Z-Wave dongles.

The next few weekends will involve some experimentation. I’m sure everyone in the house will be thrilled when Alexa no longer controls the lights…


  1. You’re killing me here. I just Googled for this topic because I’m about to start the exact same transition, for the exact same reason. I was so pleased to find this multi-part series and I am now realizing you only posted this part 1 yesterday. 🙃
    I’ll comment if I find out anything useful before you post again.

  2. Long time user of the ISY and Smart Home devices. I had an Ocelot doing x10 protocol before Insteon. I am glad I found this article.. as I also don’t want to spend the money. I just installed HA in a container on my NAS not sure yet how that will affect my PLM connectivity but I will keep reading.

    1. Running in a container comes down to making sure you have access to the hardware, which can be tricky with containers. That’s part of the reason why I moved to a dedicated hardware device (the Raspberry PI): it made the communication with the modem and Z-Wave dongle much easier.

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