In December, I had the unfortunate failure of the home QTH hot water system, the original system being a back boiler from an age gone by, along with an aged water tank, a pump, external changeover valve and an electronic time switch and manual thermostat all hard wired, after the leak I continued to use the boiler and thermostat on advice from the plumbers that the landlord had sent out, as the radiators had not been drained, only the tank, however the plumbers returned this Wednesday and removed the entire old system save for a few pipes and the radiators, rerouted the gas supply and installed a combi boiler in my large hallway cupboard, with space freed up in the smaller cupboard where the tank once was.
So, with this complete change of boiler came a new thermostat and programmer combined, put in place of the original hall thermostat, the difference is that the new thermostat is wireless, a bit of searching on the Internet later I found the exact model (the receiver is specific to the type of boiler I now have), and this afternoon, a short time ago, I listened to the 868MHz band on my good RTL-SDR (the NooElec one) and found the unit transmits at roughly 868.240MHz though I think it's closer to .245 for centre of frequency but this requires more information.
So, what to do with this, I could let it just transmit and control my boiler as anyone else but I'd like to perhaps use the data for some practical purpose, though not to control the boiler directly as this could confuse the receiver on the boiler, perhaps a simple indication of when the boiler is switched on and off so I need not look at the thermostat, or perhaps some other useful data as well, a receiver within band that can parse the data, such as an RTL-SDR of decent grade, and a Raspberry Pi for low energy draw, would work, however faults at the boiler would not be detectable.
I am also due to get a smart meter fitted for both electricity and gas a week tomorrow, naturally I am keen to see how these communicate date to the in-home display, it's obviously wireless however I don't know on which band and what protocols yet, but plenty to think about.
73 de 2E0EIJ