You may locate the model number of your thermostat in a few different ways. The first place to check is on the back of the thermostat itself. Many thermostats will have the model number printed on the back. If you can't find the model number on the back of the thermostat, try looking for it in the manual. The manual should have all of the information that you need, including the model number. If you can't find the manual, you may be able to find it online. Once you know the model number, you may use it to buy replacement components or to look for more information about your thermostat.