A programmable thermostat can come on at the exact time of day you prefer and heat or cool your house to a preset temperature, and some can do this four times a day. Many models can be set to different temperatures when you wake up in the morning, when you leave for work or school, when you come back home in the evening and when you go to bed.
For these features to work, the thermostat has to know the time of day, and Wi-Fi and smart thermostats do this automatically by connecting to the internet. The actual procedure for setting the time on a non-Wi-Fi digital thermostat depends on the model, but by and large, there's a generic one that most manufacturers use.
How to Find the Time-Set Procedure
All the programming procedures for your digital thermostat are provided in the owner's manual or the quick start-up guide that is supplied with the thermostat. You're not alone if you lost yours but don't worry — you can usually find a copy of either document online on the manufacturer's website. Just type the make and model of the thermostat into a search engine along with "manual" and you're on your way. To make it even easier, some manufacturers print instructions on the inside of the cover, so look there first.
How to Set the Time
Honeywell thermostats are common, and the procedure for setting the time on one may work on your thermostat even if it isn't a Honeywell. If you have to do this, it's either because the thermostat is new or the batteries died. Either way, be sure to put in fresh batteries before you start.
- Turn the system setting to OFF by toggling the switch to the middle position.
- Press the SET button. The clock setting will flash when you do this.
- Press the "up" arrow key to move the time forward and the "down" arrow key to move the time back. Keep pressing the arrow until the clock shows the correct time.
- Press the SET button again to set the time. The day of the week will flash below the time, so use the button to scroll to the correct day and press SET again.
How to Program Time and Temperature
Once you have programmed the time and day, you can progress to setting the thermostat for up to four different temperatures at four different times of the day. The different times are labeled WAKE, LEAVE, RETURN and SLEEP.
After you press the SET button to set the day, the first programmable time period, WAKE, will flash. Move the system toggle from OFF to either HEAT or COOL depending on which function you want and then press SET again. The time will flash, so use the arrows to toggle to the time you want, press SET again and the temperature will flash. Choose the temperature you want at that time and then press SET again to advance to LEAVE. Set the time and temperature you want and then do the same for the RETURN and SLEEP periods.
Many thermostats can be programmed for the weekend. If yours is one, SATURDAY and SUNDAY will flash at the top of the screen when you finish setting the daily schedule. After you've set the daily schedule for each day, END will be displayed on the screen, and the procedure is complete.
Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.