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Joined 4 months ago
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Cake day: May 1st, 2026

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  • All the thermostats I’ve looked at - definitely all the “smart” ones, accommodate all manner of existing wiring. If you just have a ‘normal’ HVAC with a single aircon, single furnace, and fan, or one with heat pump, backup furnace & fan, then any thermostat out there will work. If it has internal logic, it’s going to have a place for batteries, but it will also (probably) have the capability to run off furnace power, if you have the right wires. Smart thermostats will report their battery state to homeassistant, or you can just change the battery when you switch it over to heating for winter.

    Swapping a thermostat is pretty easy - it’s literally ‘connect red wire to terminal labeled red.’ It’s complicated if you care what the red, yellow, blue &c wires actually do, but the install itself is just color matching.

    If you have an extremely high efficiency HVAC, or one with multiple heat sources & multiple compressors, then there may be more than the usual 6-ish wires, but even there, it will be an exercise of taking wire from its current, clearly labeled terminal and plugging it into the same labeled terminal on the new thermostat.

    If you can stick with the same vendor for a thermostat upgrade, it may make the job very easy. I replaced a Honeywell programmable thermostat with one of their smart thermostats, and I didn’t even have to change wires. Both thermostats plugged into the same backing/terminal block. I literally pulled the old one off and pushed the new one on in 10 seconds. No tools.


  • I believe it’s that older HVAC controls don’t have a true ground/neutral, so they can’t actually consume power. Thermostat is (used to be) basically just a remote switch, just connecting the signal wire to its various functions, so there’s no need for it to have any kind of power. More recent systems have a ground (C wire), so you can draw power between the 24V R wire and the C common/ground. Some systems even put mains voltage on R.




  • Dunno how well it would work with kubernates internal networks, but my DNS is configured with different views for internal and external clients. So, when letsencrypt does a lookup, they get the external IP, but when an internal client looks up the same name, they get the internal IP. TLS is happy, because the certificate matches the name. I’m happy because it works even when the ISP is down.






  • I started doing the One True Database method because I got worried that the high write count on all the little db’s was abusing a raspberry pi’s SD card. Moved them all to a bigger server with NVME and mirroring to a RAID.

    Not all the compose files make obvious how to reconfigure the db host. Homeassistant uses s a sqlite db built into the container, rather than a separate unit, but you can force it to use a remote db through its config file. May or may not be worth hiding db user/pass in a .env And sometimes there’s trouble restarting after power failure, depending on what order the database, pi, and various containers come back up.

    I also feel it’s worthwhile. I feel better being able to check on all the databases. Feel better not writing to the SD card so much. Feel better offloading those megabytes and cpu cycles from the little pi. It’s been fun snooping through database structures. There have been a couple times where I decided to query one of the ccontain databases directly, or cross from one project to another, and it’s easier (for me) to give a different user privileges to the database and query some deep bit of data than to figure out how to extract it from an API or frontend.

    I’m not even running that many services, but why would I want the overhead of 6 separate mysql instances when I could just have one?