Honeywell PRO 4110D Programmable Thermostat Installation Guide

: June 13, 2024
: Honeywell

Honeywell PRO 4110D Programmable Thermostat

Honeywell PRO 4110D Programmable Thermostat

This is a legacy product document supported by Resideo. It is no longer manufactured.

Product Application

This thermostat provides electronic control of 24 VAC single-stage heating and cooling systems, or 750 mV heating systems.

System Types

Gas, oil, or electric heat with air conditioning
Warm air, hot water, high-efficiency furnaces, heat pumps, steam, gravity
Heat only
Heat only with fan
Cool only
750 mV heating systems

Power Type

Battery power
Common wire
Common wire with battery backup

System Settings

Heat, Off, Cool

Fan Settings

Auto, On

Must be installed by a trained, experienced technician

Read these instructions carefully. Failure to follow these instructions can damage the product or cause a hazardous condition.
Check the ratings in this booklet to verify that this product is suitable for your application.
Always test for proper operation after installation.

CAUTION: ELECTRICAL HAZARD
Can cause electrical shock or equipment damage. Disconnect power before beginning installation.

MERCURY NOTICE
If this product is replacing a control that contains mercury in a sealed tube, do not place the old control in the trash. Contact your local waste management authority for instructions regarding recycling and proper disposal.

Installation tips

Do not install in locations where the thermostat can be affected by:

Drafts or dead spots behind doors and in corners
Hot or cold air from ducts
Sunlight or radiant heat from appliances
Concealed pipes or chimneys
Unheated/uncooled areas such as an outside wall behind the thermostat

Pre-installation checklist

Package contents

Check to make sure your package includes the following items:

PRO TH4110D digital thermostat (wallplate attached to back)
Operating manual
Wall anchors and mounting screws (2 each)
AA alkaline batteries (2)
Quick reference card

Required tools & supplies

No. 2 Phillips screwdriver
Small pocket screwdriver
Drill
Drill bit (3/16” for drywall, 7/32” for plaster)
Hammer
Pencil
Electrical tape
Level (optional)

Wallplate installation

Remove the wallplate from the thermostat as shown at left, then follow directions below for mounting.

Pull wires through wire hole.
Position wallplate on wall, level and mark hole positions with pencil.
Drill holes at marked positions as shown below, then tap in supplied wall anchors.
Place wallplate over anchors, insert and tighten mounting screws.
Insert quick reference card in slot in front of wall plate.

Wiring

CAUTION: ELECTRICAL HAZARD. Can cause electrical shock or equipment damage. Disconnect power before wiring.

Wiring

Loosen screw terminals, insert wires into terminal block, then retighten screws.
Push excess wire back into the wall opening. Keep wires in shaded area as shown at left.
Plug the wall opening with nonflammable insulation to prevent drafts from affecting thermostat operation.

NOTES

R & Rc terminals
In single-transformer system, leave metal jumper in place between R & Rc. Remove metal jumper if two-transformer system.

Heat pump systems
If wiring to a heat pump, use a small piece of wire (not supplied) to connect terminals W and Y.

C terminal
The C (common wire) terminal is optional when thermostat is powered by batteries.

Wire specifications
Use 18- to 22-gauge thermostat wire. Shielded cable is not required.

Terminal Designations

W Heat relay.
Y Compressor contactor.
G Fan relay.
O Heat pump changeover valve energized in cooling.
Rc Cooling power. Connect to secondary side of cooling system transformer.
R Heating power. Connect to secondary side of heating system transformer.
B Heat pump changeover valve energized in heating.
C Common wire from secondary side of cooling system transformer.

Wiring diagrams

Power supply. Provide disconnect means and overload protection as required.
Factory-installed jumper. Remove for 2-transformer systems only.
Use either O or B terminals for changeover valve.
Use a small piece of wire (not supplied) to connect W and Y terminals.
Set fan operation switch to Heat Pump (see page 6) and configure for heat pump (see pg. 8).
Optional 24 VAC common connection.

Typical 1H/1C system: 1 transformer
Typical 1H/1C system: 2 transformers
Typical 1H/1C heat pump system
Typical heat-only system
Typical heat-only system with fan
Typical cool-only system

Fan operation settings

Gas or Oil: For gas or oil heating systems, leave the fan operation switch in this factory-set position (This setting is for systems that control the fan in a call for heat.)
Electric or Heat Pump: Change the switch to this setting for heat pump or electric heat systems. (This setting is for systems that allow the thermostat to control the fan in a call for heat, if a fan wire is connected to the G terminal.)

Power options & mounting

AC Power

The thermostat can be powered by 24 VAC power, or by batteries.
To wire the thermostat for AC power, connect the common side of the cooling transformer to the “C” terminal as shown at left.
Important: Remove R/Rc jumper for 2-transformer systems only. (See wiring diagram)

Battery Power

The thermostat can be powered by batteries alone or, if used with AC power, can provide backup power. During power interruptions the batteries will save time/day settings and power the display.

To Mount Thermostat

Align the 4 tabs on the wallplate with corresponding slots on the back of the thermostat, then push gently until the thermostat snaps in place.

Installer setup

Follow the procedure below to configure the thermostat to match the installed heating/cooling system, and customize feature operation as desired.

Installer setup

Setup Function

Setup Function	Settings & Options

1 System type

5 Heating cycle rate (CPH: cycles/hour)

9 Compressor cycle rate (CPH)

13 Adaptive Intelligent Recovery

14 Temperature display

15 Compressor protection

| 0 Gas, oil or electric heat with air conditioning
1 Heat pump (5 minute compressor off time in heating and cooling) 5 For gas or oil furnaces of less than 90% efficiency
1 For steam or gravity systems
3 For hot water systems & furnaces of over 90% efficiency
9 For electric furnaces
[Other cycle rate options: 2, 4, 6, 7, 8, 10, 11 or 12 CPH]

3 Recommended for most compressors
[Other cycle rate options: 1, 2, 4, 5 or 6 CPH]

1 On
0 Off

0 Fahrenheit
1 Celsius

5 Five-minute compressor off time
[Other options: 0, 1, 2, 3 or 4-minute off time]

Installer system test

After completing the installer setup above, press the button again to begin a system test.

Installer system test

Follow the procedure below to test the heating and cooling system.

Installer system test

Set SYSTEM switch to Cool.
Press to turn on cooling system, then check system status (see table, below).
Press to turn off cooling system.
Set SYSTEM switch to Heat.
Press to turn on heating system, then check system status (see table, below).
Press to turn off heating system.
[Optional] Set SYSTEM switch to Off to display thermostat information (see table, below). Press to display 71-76.
Press and hold to terminate system test at any time.

System Test	System Status
10 Heating system	0 Heat and fan turn off.

1 Heat turns on. Fan also turns on immediately if Fan Operation
Switch is set to Electric Heat/Heat Pump.
30 Cooling system| 0 Compressor and fan turn off.
1 Compressor and fan turn on.
70 Thermostat information (for reference only)| 71 Software revision number (major revisions)
72 Software revision number (minor revisions)
73 Configuration identification code (major)
74 Configuration identification code (minor)
75 Production configuration date code (week)
76 Production configuration date code (year)

CAUTION: EQUIPMENT DAMAGE HAZARD
Compressor protection (minimum off time) is bypassed during testing. To prevent equipment damage, avoid cycling the compressor quickly.

Adaptive Intelligent Recovery™ (Setup Function 13)

Adaptive Intelligent Recovery eliminates guesswork when setting your schedule. It allows the thermostat to “learn” how long your furnace and air conditioner take to reach the temperature you want.

Just set your program schedule to the time you want the house to reach your desired temperature. The thermostat then turns on the heating or cooling at just the right time to reach your scheduled temperature at your scheduled time.

For example: Set the Wake time to 6 am, and the temperature to 70°.The heat will come on before 6 am, so the temperature is 70° by the time you wake at 6.

Built-in compressor protection (Setup Function 15)

This feature helps prevent damage to the compressor in the air conditioning or heat pump system.

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 message Cool On (or Heat On if you have a heat pump) will flash on the display. When the safe wait time has elapsed, the message stops flashing and the compressor turns on.

$Built-in compressor protection $Setup Function 15$$

Quick reference to controls

Quick reference to display screen

In case of difficulty

If you have difficulty with your thermostat, please try the suggestions below. Most problems can be corrected quickly and easily.

Display is blank

Check circuit breaker and reset if necessary.
Make sure heating & cooling power switches are on.
Make sure equipment door is securely closed.
If battery powered, make sure fresh AA alkaline batteries are installed.

Temperature settings do not change

Make sure heating and cooling temperatures are set to acceptable ranges:

Heat: 40° to 90°F (4.5° to 32°C).
Cool: 50° to 99°F (10° to 37°C).

Heating system does not respond (“Heat On” appears on screen)

Check for 24 Vac at the equipment on the secondary side of the transformer between power and common. If voltage is not present, check the heating equipment to find the cause of the problem.
Check for 24 Vac between the heat terminal (W) and the transformer common. If 24 Vac is present, the thermostat is functional. Check the heating equipment to find the cause of the problem.
Check for loose or broken wires between the thermostat and the heating equipment.

Cooling system does not respond (“Cool On” appears on screen)

Check for 24 Vac at the equipment on the secondary side of the transformer between power and common. If voltage is not present, check the cooling equipment to find the cause of the problem
Check for 24 Vac between the cooling terminal (Y) and the transformer common. If 24 Vac is present, the thermostat is functional. Check the cooling system to find the cause of the problem.
Check for loose or broken wires between the thermostat and the cooling equipment.

Fan does not turn on in a call for heat

Make sure the Fan Operation switch is set to the proper system.

“Cool On” or “Heat On” is flashing

Compressor protection timeout is engaged. Wait 5 minutes for the system to restart safely, without damage to the compressor.

“Heat On” is not displayed

Set the System switch to Heat, and set the temperature level above the current room temperature.

“Cool On” is not displayed

Set the System switch to Cool, and set the temperature level below the current room temperature.

Accessories

Please contact your distributor to order accessories.
Cover plate assembly ……………………………………..Part Number 50002883-001 (Used to cover marks left by old thermostats.)