How To Set An Old Thermostat

If you have an old thermostat in your home, you may be wondering how to set it properly. Fortunately, setting an old thermostat is not as difficult as it may seem. With a few simple steps, you can easily adjust the temperature in your home to your desired level. In this article, we will guide you through how to set an old thermostat in an easy-to-understand language.

Step 1: Determine the Type of Thermostat

The first step in how to set an old thermostat is to determine the type of thermostat you have. There are two main types of old thermostats: mechanical and digital. Mechanical thermostats have a dial or lever that you turn to adjust the temperature, while digital thermostats have a screen and buttons that you use to set the temperature.

Step 2: Turn off the Power

Before you start adjusting your old thermostat, it is important to turn off the power to your heating or cooling system. This will prevent any accidents or damage to your system. You can turn off the power by flipping the switch on your circuit breaker or by turning off the power switch on your furnace or air conditioner.

Step 3: Set the Temperature

To set the temperature on your old thermostat, first, locate the temperature control. For mechanical thermostats, turn the dial or lever to the desired temperature. For digital thermostats, press the up or down arrow buttons to adjust the temperature. Be sure to set the temperature to a comfortable level for you and your family.

Step 4: Set the Mode

Your old thermostat may have different modes, such as heat, cool, or off. To set the mode, simply turn the mode dial or press the mode button on your digital thermostat. If you want to turn off your heating or cooling system, set the mode to off.

Step 5: Adjust the Fan

Some old thermostats have a fan control that allows you to adjust the speed of the fan. To adjust the fan, turn the fan control dial or press the fan button on your digital thermostat. You can set the fan to auto, which means it will turn on and off automatically with your heating or cooling system, or to on, which means it will run continuously.

Step 6: Wait for the System to Respond

After you have set the temperature, mode, and fan, wait for your heating or cooling system to respond. It may take a few minutes for the system to turn on or off, so be patient. If you do not feel any changes in temperature, check to make sure that the power is on and that the thermostat is set correctly.

Frequently Asked Questions

Q: How do I know if my old thermostat needs to be replaced?

A: If your old thermostat is not functioning properly or is outdated, you may want to consider replacing it with a newer, more efficient model. Look for signs such as inaccurate temperature readings, frequent breakdowns, or high energy bills.

Q: Can I install a new thermostat myself?

A: If you have some basic electrical knowledge, you may be able to install a new thermostat yourself. However, it is recommended that you hire a professional to ensure that the installation is done safely and correctly.

Q: How often should I replace my thermostat?

A: It is recommended that you replace your thermostat every 10 years or so, depending on the type and condition of your thermostat.


Learning how to set an old thermostat is a simple process that can help you save money on your energy bills and keep your home comfortable. By following the steps outlined in this article, you can easily adjust your old thermostat to your desired temperature and mode. If you have any questions or concerns about your thermostat, be sure to consult with a professional.