Recently I went through some pain with this myself. Had a full Heatmiser setup with wireless receivers in every room and 2 manifold controllers for our underfloor heating on two floors.
The devices ate batteries like nothing I've seen before and regularly dropped off the network and didn't send call to heat signals properly, so I decided to switch out the thermostats for cheap ZigBee temperature sensors.
I then ordered a relay board from AliExpress with a baked in esp8266 cheap and flashed esphome onto it. These replaced my manifold controllers
After trial and error, I now have my heating system run by esphome and home assistant. It has been faultless! Will probably reinstall the Heatmiser kit if I sold the house though