This Honeywell ST9120C wireless RF single-channel programme timer is an essential component for any storage tank water heater. It is designed to work with thermostats and is compatible with a range of features, making it an ideal choice for those who want to enjoy the convenience of a programmable water heater. Whether you're looking to upgrade your current heater or replace a faulty one, this timer is the perfect solution. With its easy-to-use interface, you can easily programme the timer and enjoy a range of features that will help you save energy and improve the efficiency of your water heater. It is also compatible with a range of different water heaters, making it an excellent choice for anyone who wants to upgrade their heating system.