The batteries should last at least 18 months so there is obviously something amiss with the Thermostat. I am an Electronic Systems Engineer and I have a Salus IT 500 System controlling my Boiler and switching a solenoid Motorised Valve for the Hot Water heating. It has the Wireless Thermostat, an Internet Gateway and an IT 500 RX Receiver which recently after 9 years Died, NO LIGHTS. I have diagnosed the root cause in the actual receiver electronics and replaced the faulty components and working perfectly. As I say my Thermostat batteries last at least 18 months between changes so your unit must be faulty. If anybody has Dead IT 500 RX Receivers, rather than spend £100 + for a complete new system I can repair the receivers and return for £30. My name is Paul, Phone 07514874120 for Salus Repairs to IT 500 RX Dead Units, but your Thermostat would be better replaced, as a repair would probably not be cost viable to do, and Salus certainly will not repair any of their own stuff, you actually would even struggle to get an answer to any questions from them as all they do is send you a link to F.A.Qs
Paul, July 2022
