Setup: Control4 C4-THERM Wireless Thermostat User Guide

Content

Overview

The C4-THERM Wireless Thermostat is a smart climate-control device designed for integration with a Control4 home automation system. It manages heating, cooling, fan operation, and selected indoor air quality equipment from the thermostat or a connected Control4 interface.

The thermostat is intended for homes with compatible HVAC equipment and can support advanced functions such as humidification, dehumidification, ventilation, Event-Based air cleaning, programmable schedules, presets, and wireless system communication.

Specifications

Model: C4-THERM; supported thermostat model: C4-THERM-WH
Power: 24 VAC, four alkaline AA batteries, or both for backup power
Heating capability: Up to four heating stages
Cooling capability: Up to two cooling stages
Fan modes: On, Auto, and Circ
System modes: Em Heat, Heat, Off, Cool, and Auto when enabled during installation
Control features: Temperature control, compressor protection, system test mode, progressive recovery, and message-center feedback
Indoor air quality functions: Humidification, dehumidification, ventilation, and Event-Based air cleaning when installed and configured

Detailed Description

The thermostat uses a backlit display and front-panel controls to show the current indoor temperature, temperature setpoint, system mode, fan mode, hold status, indoor air quality setting, battery condition, and wireless signal strength. The first button press activates the backlight, which turns off automatically after a period of inactivity.

The system mode control determines whether the connected HVAC equipment heats, cools, remains off, or selects heating or cooling automatically. Emergency Heat is intended for heat-pump systems with auxiliary heat; in this mode, the auxiliary heat operates while the heat pump remains off.

Temperature adjustment buttons can temporarily change the active setpoint even when a schedule is running. Fan control determines whether the blower operates continuously, only during heating or cooling, or for at least 30 minutes per hour in circulation mode.

The C4-THERM Wireless Thermostat can retain system settings during a power interruption. If both AC and battery power are removed, the clock resets; time synchronization is restored through the Control4 system.

Safety

Installation must comply with applicable national and local electrical codes.
Do not use this thermostat with line-voltage baseboard heaters.
Incorrect installation or operation can damage property or HVAC equipment.
Operate the device only within the limits specified for the thermostat and its installation instructions.
Use the product only for the functions described in the user guide. Improper use can invalidate warranty protection.

Setup and Operation

Selecting the System Mode

Press the system mode button to cycle through the available modes. The selected mode flashes while it is being changed. Stop pressing buttons and wait approximately five seconds for the thermostat to accept the selection.

Em Heat: Uses auxiliary heat only on compatible heat-pump systems.
Heat: Operates the heating system without cooling.
Off: Turns heating and cooling operation off.
Cool: Operates the cooling system without heating.
Auto: Selects heating or cooling automatically when enabled by the installer.

Changing the Temperature

Use the temperature adjustment buttons to raise or lower the current setpoint. When a programmed schedule is active, the change creates a temporary hold unless another hold option is selected.

Selecting the Fan Mode

Press the fan mode button to choose the required blower behavior. The selected mode flashes and is accepted after approximately five seconds without another button press.

On: Runs the fan continuously for maximum circulation and filtering.
Auto: Runs the fan only when heating or cooling is operating.
Circ: Operates like Auto while ensuring that the fan runs for at least 30 minutes per hour.

A fan selection made during a programmed event remains active until the next event begins. To run the fan continuously through all scheduled events, the schedule must be configured for Fan On.

Maintenance Reminders

Maintenance reminders are configured by the installer and indicate when HVAC service may be due. If a reminder appears, arrange service with a qualified HVAC professional.

To clear reminders at the thermostat, set the system mode to Off and hold the indicated button continuously for five seconds. When the Service Reminders prompt appears, select Yes, move through the listed reminders, choose which reminders to reset, and select Done. Reminders can also be reset through the Control4 system.

Screen Lockout

Installer-configured lockout settings can prevent changes from being made at the thermostat. To temporarily override the lockout, press and hold the designated button for five seconds.

Battery Replacement

The thermostat can run from AC power, battery power, or both. When both are connected, the batteries can provide backup power for communication with the Control4 system. Four alkaline AA batteries are used.

Remove the thermostat bezel as directed for access to the battery compartment, then replace all four batteries with fresh alkaline AA cells. Observe the polarity markings inside the compartment. The thermostat retains system settings through a power interruption, but the clock may need to resynchronize after complete power loss.

Indoor Air Quality Functions

Event-Based Air Cleaning

When an air-cleaning system is installed, its operating mode is controlled through the Control4 system rather than directly from the thermostat. Air cleaning may also occur during normal fan operation or other indoor air quality events.

Off: Does not call for the fan solely for air cleaning.
Constant Clean: Runs the air cleaner continuously.
Automatic: Targets at least 30 minutes of air-cleaning operation per hour while considering normal HVAC runtime.
Event Clean: Runs continuously for three hours, then returns to the previous operating mode.
Allergies: Runs continuously for 24 hours, then returns to the previous operating mode.

The thermostat coordinates fan operation when air-cleaning settings overlap with heating, cooling, or other indoor air quality functions.

Humidifier Control

If a humidifier is installed, press the indoor air quality button and select Humidify to open the humidifier controls. The installer determines whether the thermostat uses automatic or manual humidity control.

Automatic Humidity Mode

Automatic mode adjusts the target indoor humidity according to outdoor temperature. Begin with the humidity setting at level 3, which is a normal starting point. Observe comfort and household conditions for the next 24 to 48 hours, then make small adjustments if necessary. Additional adjustment may be needed during the coldest part of the first heating season because building construction affects indoor humidity.

Manual Humidity Mode

Manual mode requires the humidity setting to be adjusted when outdoor temperatures change. Lower humidity targets help reduce condensation during cold weather.

Outside temperature around 50°F: recommended indoor relative humidity 50%
Outside temperature around 40°F: recommended indoor relative humidity 45%
Outside temperature around 30°F: recommended indoor relative humidity 40%
Outside temperature around 20°F: recommended indoor relative humidity 35%
Outside temperature around 10°F: recommended indoor relative humidity 30%
Outside temperature around 0°F: recommended indoor relative humidity 25%
Outside temperature around -10°F: recommended indoor relative humidity 20%
Outside temperature around -20°F: recommended indoor relative humidity 15%

Dehumidifier Control

If dehumidification is installed, the thermostat can control either a whole-home dehumidifier or the air conditioner, depending on installer configuration. Select Dehumidify from the indoor air quality controls to open the dehumidifier screen.

Set the initial dehumidification target to 60% relative humidity. Allow the system time to reduce the initial moisture level before making further changes. Raise the target to reduce runtime and allow a more humid indoor environment; lower it to produce drier air and increase dehumidification runtime.

A newly installed system may operate for an extended period because moisture stored in building materials gradually returns to the air after the first drying cycle. If windows are opened, turn dehumidification off as you would turn off air conditioning. During extended summer absences, a 60% humidity target can help limit moisture while a higher cooling setpoint reduces unnecessary energy use.

When the air conditioner performs dehumidification, the thermostat may cool up to 3°F below the cooling setpoint. This additional cooling may not always be sufficient to reach the selected humidity target.

Fresh Air and Ventilation

Fresh Air controls are available when ventilation equipment is installed. Press the indoor air quality button and select Fresh Air to open the ventilation controls.

Off: Prevents ventilation operation.
Automatic: Cycles ventilation according to installer-defined requirements and limits.
3 Hour Event: Runs ventilation continuously for three hours, then returns to the previously active Off or Automatic mode.
24 Hour Event: Runs ventilation continuously for 24 hours, then returns to the previously active Off or Automatic mode.

Program Schedules and Holds

Schedule Management

Schedules are created and edited through a Control4 touchscreen, on-screen interface, or mobile interface. The thermostat is shipped with programming disabled, so schedule and hold functions are unavailable until programming is enabled through the Control4 system.

Each day can be scheduled separately, and a schedule can be copied from one day to another. Scheduled events use presets, and there is no stated limit to the number of events that can be assigned to a day.

Progressive Recovery

Progressive recovery starts heating or cooling before a scheduled event when necessary so the desired temperature is reached at the event’s start time. For example, the system may begin heating before a morning event rather than waiting until the scheduled time.

Equipment Wait

Built-in equipment protection enforces minimum on and off times for connected HVAC equipment. When the system is preventing a compressor or other equipment from starting, an equipment-wait message appears and the related status icon flashes.

Hold Options

Press the hold button to display the available hold types. The current selection flashes and is accepted after approximately five seconds without another button press.

Next Event: Holds the selected temperature and fan mode until the next scheduled event.
2 Hour: Overrides scheduled temperature and fan settings for two hours.
Permanent: Keeps the selected temperature until the hold is canceled.
Timed: Holds settings until a selected date and time. This option must be configured through a Control4 touchscreen, on-screen interface, or mobile device and cannot be set directly at the thermostat.

Pressing the hold control again after the available options are shown can cancel an active hold. Temperature and fan settings can be adjusted while a Next Event, 2 Hour, or Permanent hold is active.

Presets

Presets provide a convenient way to switch between commonly used temperature and fan settings, such as Home, Away, or Vacation. Presets are created and edited through a Control4 user interface.

To select an existing preset at the thermostat, press the preset control until the desired preset appears in the message center. Presets can also be selected from the thermostat screen in a Control4 interface.

Troubleshooting

The display is dark: Press a button to activate the backlight. If the thermostat remains unresponsive, check for AC power and replace depleted AA batteries.
The system does not start immediately: Look for an equipment-wait message. The thermostat may be enforcing compressor protection timing before allowing equipment to operate.
The schedule cannot be changed at the thermostat: Manage schedules through the Control4 touchscreen, on-screen interface, or mobile interface. Scheduling is not performed directly on the thermostat.
A program function is unavailable: Programming may be disabled in the Control4 system. Enable programming before using schedules or related holds.
A service reminder remains visible: Reset the selected reminder using the thermostat’s Service Reminders process or through the Control4 system. If service is still required, arrange HVAC maintenance.
Humidity control runs longer than expected: Newly installed humidification or dehumidification equipment may need additional time to bring the home and its materials to the target humidity level.
Wireless communication is interrupted: Check the thermostat’s wireless signal indicator, confirm that power or battery backup is available, and allow the Control4 system to resynchronize.

Pros & Cons

Pros

Supports multi-stage heating and cooling.
Offers integrated humidification, dehumidification, ventilation, and air-cleaning functions when compatible equipment is installed.
Provides flexible fan circulation and multiple hold options.
Includes progressive recovery and compressor protection.
Can use AC power, batteries, or both for backup operation.
Works with Control4 schedules, presets, and remote interfaces.

Cons

Scheduling and timed holds require a Control4 user interface rather than the thermostat alone.
Several indoor air quality functions require additional HVAC equipment and installer configuration.
Automatic and advanced system modes may not be available unless enabled during installation.
Complete power loss resets the thermostat clock until it synchronizes with the Control4 system.

PDF

Faqs

How do I select the correct heating or cooling mode on the C4-THERM Wireless Thermostat?

Press the System Mode button repeatedly to cycle through Em Heat, Heat, Off, Cool, and Auto when those options are enabled by the installation. Em Heat is intended for heat pumps with auxiliary heat and uses the auxiliary heat without operating the heat pump. Heat runs heating only, Cool runs cooling only, and Off disables both systems. Auto allows the thermostat to choose heating or cooling automatically. Stop pressing buttons and the flashing selection will be accepted after about five seconds.

Why does the C4-THERM show an equipment wait message after changing the temperature?

Equipment wait indicates that the thermostat is temporarily delaying operation to protect the heating or cooling equipment. The C4-THERM enforces minimum operating and off times, so a compressor or other equipment may not start immediately after a mode change or temperature adjustment. Wait for the message to clear rather than repeatedly switching modes. If the delay continues unusually long, check whether the system is powered and contact a qualified HVAC professional for equipment diagnosis.

How do I set the fan to run continuously or circulate air automatically?

Press the Fan Mode button to choose On, Auto, or Circ. On keeps the fan running continuously for maximum circulation and filtering. Auto runs the fan only while heating or cooling operates. Circ works like Auto but ensures at least 30 minutes of fan operation each hour, balancing air movement with energy use. A fan selection made during a scheduled event remains active until the next event unless the schedule specifies continuous fan operation.

How can I replace the batteries in the C4-THERM Wireless Thermostat?

The thermostat uses four alkaline AA batteries and may also receive power from a 24VAC connection. Remove the thermostat bezel as shown in the installation instructions to reach the battery compartment, then replace all four batteries with fresh alkaline cells while observing polarity. Batteries can provide operation or backup communication during an AC interruption. Thermostat settings are retained through a power interruption, but the clock resets if both AC power and batteries are removed.

What should I do when a maintenance reminder appears on the thermostat?

A maintenance reminder means the installer-configured service interval has been reached. Arrange appropriate HVAC service before resetting the reminder, because clearing it does not perform maintenance or repair equipment. To reset reminders at the thermostat, set the system mode to Off and hold the designated button for five seconds. Choose Service Reminders, select the reminders to reset, and confirm with Done. Reminders may also be reset through the Control4 climate-control interface.

How do I adjust humidification settings on the C4-THERM?

If a humidifier is installed, select Humidify to open the Humidifier Control screen. Automatic mode adjusts indoor humidity according to outdoor temperature, helping reduce condensation risk during cold weather. Manual mode requires you to lower the humidity target as outdoor temperatures fall. Begin near the normal setting and monitor comfort, condensation, and the home’s conditions over the next day or two. Humidity control depends on installer configuration, so unavailable options may indicate that no humidifier is connected.

How does dehumidification work with the C4-THERM Wireless Thermostat?

When dehumidification is installed, select Dehumidify and set the desired indoor relative humidity. A higher target reduces dehumidifier run time, while a lower target removes more moisture. An initial setting around 60 percent allows the home to dry before further adjustment based on comfort. If the air conditioner provides dehumidification, the thermostat may cool up to 3°F below the cooling setpoint. Turn dehumidification off when windows are open to avoid unnecessary operation.

How do I override the schedule or create a temperature hold?

Press the Hold button to choose Next Event, 2 Hour, or Permanent hold. Next Event temporarily changes temperature and fan settings until the next scheduled event. A 2 Hour hold keeps the adjustment for two hours, while Permanent hold overrides scheduled temperature changes until canceled. You can also adjust the setpoint directly while a schedule is running to create a Next Event hold. Timed holds with a specific ending date and time must be created through a Control4 touchscreen, on-screen interface, or mobile device.