What is the history of the Honeywell round thermostat?

Author: Jamaal Durgan II  |  Last update: Monday, March 17, 2025

The Round was introduced to the public in 1953, when Minneapolis-Honeywell was seeking a new product to increase sales. The T-86 Honeywell Round thermostat—known simply as The Round—was easy to make, easy to use, and easy to identify. Sales to both contractors and homeowners soared.

How can I tell how old my Honeywell thermostat is?

For most thermostats, the CRC and MAC ID are located on the back of the detachable face plate. For RedLINK products, they are located on the RedLINK Internet Gateway. DATE CODE – This describes the date the thermostat was built.

What is the best year round thermostat setting?

We recommend the following as the best thermostat settings:
  • For warmer times, set your thermostat at 78° F during daytime. Set it to 86° F if you leave the house.
  • For cooler times, set your thermostat to 68° F while you're at home and awake. Lower it to 65° F when you sleep.

Do old round Honeywell thermostats have batteries?

Many of the traditional round Honeywell thermostats have a CR2450 battery that may need to be replaced. If your thermostat is of this type and needs a new battery, the video should give you an insight into how this is done.

Do Honeywell round thermostats go bad?

Most household thermostats will last about ten years. As they get older, they start to malfunction and become unreliable.

Honeywell Round Thermostat Temperature Reading Adjustment

Can a Honeywell thermostat work without batteries?

Batteries are typically used as a backup to retain settings during a power outage. Without batteries, the thermostat can maintain the temperature but might lose customized settings if the power fails.

Is 78 too hot for a house?

Quick answer: The ideal house temperature is room temperature, which ranges from 68 to 78 degrees F, though this may vary from season to season. In winter, the average room temperature is generally 62 to 68 degrees, whereas in the summer, the average temperature is 72 to 78 degrees.

Is it cheaper to leave your thermostat at one temperature?

Keeping your home at a constant temperature generally means that your HVAC system will run constantly to meet it. This means that your furnace or air conditioner may run when you're asleep, at work, or out of the house. This wastes more energy than the minimal amount that you might save by having it constantly run.

Is 72 too high for a thermostat in winter?

68 to 72 degrees is a temperature range that is not too warm or cool, and is sufficient enough to warm up the home just enough so that everyone is comfortable regardless of the type of clothing they have on.

What are the old round thermostats called?

The Round was introduced to the public in 1953, when Minneapolis-Honeywell was seeking a new product to increase sales. The T-86 Honeywell Round thermostat — known simply as The Round — was easy to make, easy to use, and easy to identify.

Can I replace my old Honeywell thermostat with a new one?

To further help, many Honeywell Home T-Series thermostats are mounted on a Universal Wall Plate that allows you to change models by simply 'popping' one in place of the other.

How do I set the temperature on my Honeywell round thermostat?

Adjust Temperature Setting

To lower the temperature setting, turn the dial counterclockwise. To raise the temperature setting, turn the dial clockwise.

What is the lifespan of a Honeywell thermostat?

The average lifespan of a Honeywell thermostat is typically around 10-20 years, depending on various factors such as usage, maintenance, and environmental conditions. With proper care and regular servicing, a Honeywell thermostat can last even longer.

How do I know if my Honeywell thermostat needs to be replaced?

Signs You Need a New Thermostat
  1. Heating or cooling system will not turn off or on.
  2. The temperature reading is incorrect.
  3. Recent spike in your energy bill.
  4. Frequent temperature fluctuations.
  5. Thermostat is 10 years old or older.

How to use an old Honeywell thermostat?

It's easy:
  1. Select the desired temperature by turning the dial, moving the lever or pushing the up/down buttons.
  2. Turn the fan to Auto to make it come on when the furnace or air conditioner does. If you want the fan without heat or air conditioner, turn it On.
  3. Set the mode to Heat or Cool depending on the season.

Why is my AC thermostat set at 74 but reads 78?

If the temperature is set to 74°F but the thermometer shows 78°F, you will have to recalibrate the thermostat to account for this 4-degree deviation. Even with older AC units or furnaces, you might have to recalibrate your thermostat from time to time.

What is the coldest you should set your thermostat?

Don't set your thermostat too low

“You have to keep it really low to really get into a health concern," he said. "What you want to do is keep it at a reasonable temperature that's not chilly.” The World Health Organization recommends keeping indoor temperatures between 64 and 75 degrees for healthy people.

What temperature to keep a house in winter?

The U.S. government Department of Energy (DOE) states that people should set their thermostats to 68 degrees F. This is the optimal temperature for keeping a home comfortable.

What is a good house temperature for seniors?

Many seniors find 78 degrees to be the most comfortable indoor temperature. Anywhere from 65 to 78 degrees is considered safe.

Can you sleep in 78 degrees?

“Anything under 68 degrees overall is ideal for sleep. If you get too hot in the middle of the night, reduce layers of clothing or sheets, turn on fans, or drink a little cold water.”

What is a good temperature for the AC?

According to the Department of Energy1, 78° Fahrenheit is the sweet spot for air conditioners to balance energy savings and comfort when people are at home and need cooling.

How do I know if my Honeywell thermostat battery is low?

Most Honeywell thermostats have a low battery indicator light or display a “Low Batt” message, giving you about 60 days to replace the batteries. Ignoring these signs can lead to more than just an uncomfortable home temperature.

Does Honeywell thermostat work if power goes out?

The system has a backup battery to sustain power in case of a power outage. If a separate Cellular communicator is installed, that will be used as a backup to the IP communicator.

What does it mean when your Honeywell thermostat is blank?

If you own a Honeywell thermostat, the blank screen could be an indication of a furnace door that wasn't completely closed. These thermostats are programmed to shut off entirely if a furnace door is open. To rule this out, double-check to make sure your furnace door is fully closed.

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