I currently have a hive system connected to home assistant but also have smart TRV’s connected via Zigbee directly to HA. I was looking at removing the hive hub and just integrating the thermostat and boiler controller directly into HA if that’s possible?
The only thing I’m unsure about is if I can recreate the hive “ready by” function where as it will turn the heating on earlier than the schedule so the room is warm by the scheduled time.
Hope someone is reading this as is an old original post.
Surprised you got no anwers. I have a similar problem in that I want to implement a ready by routine. Some call it prewarm but my seach for “prewarm” here only came up with one not very relevant post and “ready by” is barely mentioned either.
A colleague did it before on a Pi and it’s not easy as the software has to coninuously look ahead several hours to see what ON events are coming up. Then work out when to start the boiler based on current temperature and the thermal mass of the building. He used a fixed thermal mass, like 4C rise per hour, based on experiment.
But Hive is more clever in that it works out this thermal mass based on past history. And if it does it correctly it should reassess the result every month or two ( or continuously) as it varies with the outside tempertures, as losses are higher and wall tempertures are lower in the winter.
I need a 5 hour look ahead but Hive only does 1 hour, maybe because the processor load of all this is high and 5 hours makes it higher.
To answer your other point what about doing what I am doing which is to use a Shelly 2 output wifi relay to switch the boiler? And a Shelly wifi wall temperture display to get the temperature?
One problem with Shelly is they are not changeover relays and a standard Y plan boiler needs one output to be changeover. But you can easily add a small external changeover relay triggered by the Shelly relay.
Someone else might sell a wifi unit with changeover but I am trying to stick to Shelly hardware to minimise my learning curve.
I’d be interested to hear what brand of TRVs you are using and if you’d recommend them as I want to add these too.
From reading here the problems seem to be:
Some are unreliable.
Some like Shelly (I think) are on or off with no modulation in between.
Some won’t give you the room temperature reading so need a separate temperature sensor in each room.
I’d rather have wifi TRVs but I do have a HA zigbee dongle, currently unused.
How do you tell the boiler to switch on/off? I.e. once the room temperature is up to set point the TRV shuts off. How do you detect that and so tell the boiler to go off when all TRVs are shut? Easier if you have separate room temperature sensors I guess. I am trying to avoid such sensors and just use the ones in the TRVs even though it’s less precise in tempertre control (precision does not matter in my particular application).