Not all thermostats will work compatibly with all HVAC systems nor are they all created equal. It is important to understand a few basic things about selecting the appropriate replacement thermostat before you make your purchase. With the right recommendations, you can avoid that annoying trip to the return counter at your local home improvement store.
First of all, you need to figure out what type of control your system requires. Most utilize a low-voltage thermostat control (about 24v) but verify what your needs are before you buy. It could be a line voltage (110 or 220v) or a millivolt (75mv). You may be able to look up the specifications online, for your system.
Next, you need to figure out the features you would like to have on your thermostat. There are always more basic models available along with the fancier versions. 24-hour programming is a popular feature that allows you to preset temperatures for various times of the day, based on your family’s schedule.
With a PID controller built into the unit, you can be even more efficient at obtaining the right temperature at the right time of day. For example, with a basic unit, if you set it to 68 degrees Fahrenheit for 6:00 am, it will start up the heater at 6:00 am. So your first several minutes of the morning will be cold.
But, if you have a built-in PID controller in the thermostat you’ve chosen, it will start warming up the house beforehand, so that when you wake up at 6:00 am, it has heated up to a more comfortable 68 degrees. While you may be tempted to buy the basic stripped-down model, you may find that having the programmable temperature saves you far more money on utilities than you’ll spend on the difference between the two units