PRO 3000 Non-Programmable Thermostat

PRO Install

The brand you trust. The thermostat you can rely on.

Our PRO 3000 Non-Programmable Thermostat offers basic operation such as a slide switch for selecting heat, cool or operate the fan. The backlit digital display makes temperature and settings easier to read in various lighting conditions. And with a name like Honeywell, you can expect years of reliable service.

  • Backlit digital display
  • Basic operation
  • Displays both current and set temperature
  • Five-year warranty
  • Professional installation
  • Model numbers: TH3110D1008, TH3210D1004
  • Color: White
  • Dimensions: 3-13/16 in. High X 5-3/8 in. Wide X 1-1/4 in. Deep


Honeywell thermostats have a model number that begins with a TH, T, RTH, CT, TL or RLV. The location of the model number varies depending upon the thermostat. If the thermostat is battery operated and the batteries are accessed from the front of the thermostat, please check the area around the batteries. If the batteries are on the back of the thermostat or if the thermostat is not battery operated, the model number should be on the back of the thermostat once the thermostat is removed from its base. If your thermostat has a mechanical clock, the model number is on a sticker on the horizontal surface above the clock.
Yes, the packaging contained with the thermostat is recyclable. Information about recycling thermostats containing mercury can be found at:
The thermostat takes the temperature override as a need to reach the new temperature setting right away. It will run the second or third stage only as long as necessary to reach new temperature setting.
"Auto" under "System" indicates that it is setup to automatically switch between heating and cooling. If your thermostat does not show auto, you may not have this feature.
The changeover valve is a device which reverses the flow of refrigerant in the heat pump. This will allow the freon to reverse and heat the home or cool the home. Honeywell uses an O terminal to energize the valve in cooling and a B terminal to energize the valve in heating. Some manufacturers of heat pumps may use the B terminal to energize in heating, while a vast majority energize the O terminal in cooling.
The FAN selection key has two or three positions: Auto and On and sometimes Circ (Circulate). The Auto position will allow the system fan to operate whenever the heating or cooling system is turned on by the thermostat. The On position will turn the fan on to run continuously, regardless whether heating or cooling system is turned on by the thermostat or not. The Circ (Circulate) position if available will run the fan approximately 35% of the time, minus any time the fan will run with the heating or cooling system.
Honeywell offers thermostats for both low voltage (24 volts) and line voltage (120 or 240 volts) systems. The most common type of voltage from a central heating and/or cooling system is 24 volts (24Vac). The old thermostat may say somewhere on the thermostat that it is for 24 volt (24Vac) or maximum 30 volts (30Vac). If you see 120 Vac or 240 Vac on the thermostat, a low voltage thermostat will NOT work with your system. You will need a line voltage thermostat. This type of voltage is common with electric baseboard heating. Regardless of the voltage, Honeywell strongly suggests that you turn off the power to the system at the furnace, at the fuse, or at the circuit breaker panel before installing or replacing a thermostat. If you are unsure about your voltage, please contact a local heating and cooling contractor in your area for assistance.
Your thermostat is designed to control temperature to +/- 1 F. How often your heat turns on and off depends on may factors including the type of heating system you have, as well as how much your system needs to run to maintain your temperature setting (in other words, how cool or cold it is outside). A typical forced air system will cycle about five times in an hour (5CPH), this is normal. A typical hot water system would cycle less then that
A heat pump is a single system that provides both heating and cooling to the home. For example, the air conditioner may prove both heating and cooling to the home - this is called a heat pump. Often the heat pump also has some sort of backup or auxiliary heat for when it is cold outside. The backup or auxiliary heat could be electric heat strips or a fossil fuel furnace. Thermostats that control heat pumps with backup or auxiliary heat typically have an Em Heat (Emergency heat) position. When the system switch is moved to the Em Ht. position, the auxiliary heat is activated on a call for heat. The compressor is disabled.
Honeywell thermostats do not have the capability of making an audible noise such as a beeping sound. The noise you are hearing is likely from another electronic device which is near the thermostat. Check for a smoke detector, door bell, or security system.