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Honeywell T4 Pro Programmable Thermostat User Guide

T4 Pro Programmable Thermostat User Guide For TH4110U2005, TH4210U2002 series
Package Includes:

  • T4 Pro Thermostat
  • UWP™ Mounting System
  • Decorative Cover Plate
  • Screws and Anchors
  • 2 AA Batteries
  • Thermostat Literature

System operation settings

Honeywell T4 Pro Programmable Thermostat User Guide
  1. Press the Mode button to cycle to the next available System mode.
  2. Cycle through the modes until the required System mode is displayed and leave it to activate.

NOTE: Available System modes vary by model and system settings.
System modes:
‒ Auto
‒ Heat
‒ Cool
‒ Off
‒ Em. Heat (TH4210U only)

Program schedule override (temporary)

  1. Press + or - to adjust the temperature.
  2. Once at the desired setpoint temperature, no further action is needed. The new setpoint temperature will be held until the next scheduled time period begins. For more information on schedule time periods, see “Program Schedule” on page 3.
  3. To cancel the Temporary Hold, Press + or - and then press Cancel.

Program schedule override (permanent)

  1. 1 Press + or - to adjust the temperature.
  2. 2 TEMPORARY HOLD is displayed and the setpoint temperature flashes. While it’s flashing, press Hold (Mode) button to change to Permanent Hold.
  3. 3 To cancel the Permanent Hold, press + or - and then press Cancel.

Adaptive Intelligent Recovery
Over time, the T4 Pro Thermostat “learns” how long it takes your system to reach the temperature you want. It turns on the heating or cooling system earlier to make sure you’re comfortable at the time you expect.

Built-in compressor protection
Damage can occur if the compressor is restarted too soon after shutdown. This feature forces the compressor to wait for a few minutes before restarting. During the wait time, the display will flash the message Cool On (or Heat On if you have a heat pump). When the safe wait time has elapsed, the message stops flashing and the compressor turns on.

Battery replacement
Batteries are optional (to provide backup power) if your thermostat was wired to run on AC power when installed. If your thermostat was not wired to run on AC power, then batteries are required. Install fresh batteries immediately when the low battery icon appears. The icon appears about two months before the batteries are depleted.

Even if the low battery icon does not appear, you should replace batteries once a year, or before leaving home for more than a month. If batteries are inserted within two minutes, the time and day will not have to be reset. All other settings are permanently stored in memory, and do not require battery power.

NOTE: When replacing batteries, alkaline batteries are recommended.

Troubleshooting
If you have difficulty with your thermostat, please try the following suggestions. Most problems can be corrected quickly and easily.
Display is blank

  • Check circuit breaker and reset if necessary.
  • Make sure power switch for heating & cooling system is on.
  • Make sure furnace door is closed securely.
  • Make sure fresh AA alkaline batteries are correctly installed (see page 6).

Heating or cooling system does not respond

  • Press Mode button to set system Heat (see page 2). Make sure the desired temperature is set higher than the inside temperature.
  • Press Mode button to set system Cool (see page 2). Make sure the desired temperature is set lower than the inside temperature.
  • Check circuit breaker and reset if necessary.
  • Make sure power switch for heating & cooling system is on.
  • Make sure furnace door is closed securely.
  • Wait 5 minutes for the system to respond.

Temperature settings do not change

  • If display says “unlock”; see page 5. If not, verify you are in the correct mode (heat, cool, em heat or auto); see page 2.
  • If you are in the correct mode, but you cannot set the heat from 40 °F to 90 °F (4.5 °C to 32 °C), or set the cool from 50 °F to 99 °F (10 °C to 37 °C), you may have range-stops restricting your setting. Check with the installer to see if they set range-stops.

“Cool On” or “Heat On” is flashing

  • Compressor protection feature is engaged. Wait 5 minutes for the system to restart safely, without damage to the compressor (see page 5).
Electrical Ratings
Terminal Voltage (50 Hz/60 Hz) Running Current
W Heating 20 Vac - 30 Vac 0.02 A - 1.0 A
W2 (Aux) Heating (TH4210U only) 20 Vac - 30 Vac 0.02 A - 1.0 A
E Emergency Heat (TH4210U only) 20 Vac - 30 Vac 0.02 A - 0.5 A
Y Compressor Stage 1 20 Vac - 30 Vac 0.02 A - 1.0 A
G Fan 20 Vac - 30 Vac 0.02 A - 0.5 A
O/B Changeover 20 Vac - 30 Vac 0.02 A - 0.5 A
L/A Input 20 Vac - 30 Vac 0.02 A - 0.5 A