Lennox Harmony III™ Zone Control System

What Is the Harmony III™ Zone Control System?

The Lennox Harmony III™ Zone Control System manages the distribution of conditioned air to as many as four specific areas or zones in the home. This advanced control system allows a home to be zoned for heating and cooling without the extra expense of purchasing two or more HVAC (Heating, Ventilation, and Air Conditioning) systems. This control allows the owner to heat or cool occupied areas, without conditioning unused areas. The system adapts the HVAC components to provide a balanced and comfortable environment.

What does the system consist of?

The principle system component is the control center, which acts as the "brains" of the Harmony III™ Zone Control System. It coordinates all of the operations of thermostats, motorized dampers, and HVAC equipment.

The Harmony III™ Zone Control System uses off-the-shelf 1-heat/1-cool, non-power-robbing, non-heat pump electronic thermostats and motorized dampers with one of the following Lennox HVAC systems to distribute conditioned air to zones:

• Option 1: Gas Furnace with Variable Speed Blower Motor (VSM) and either a single- or two-speed condensing unit.
• Option 2: Blower coil unit with Variable Speed Blower Motor and either a single- or two-speed heat pump.
• Option 3: Gas furnace with Variable Speed Blower Motor and heat pump.
• Option 4: Adding Humiditrol® Interface to any of the above options.

How do I set the control center switches?

The Harmony III™ control center has two ON/OFF switches. For the most part, the system relies on thermostats to provide control of the desired comfort level for each zone. The control center also features LEDs (light emitting diodes) which light to indicate the current operating mode and which zone dampers are closed.

NOTE: Later models of the Harmony III™ control center board include connecting points for a remote vacation switch, which may be installed near the Zone 1 thermostat for homeowner convenience.

1. Vacation Switch

The Harmony III™ control center operates in either of two modes:

• Central mode (Vacation switch ON): All zones receive conditioned air simultaneously, similar to traditional, non-zoned HVAC systems. The master thermostat (located in Zone 1) controls any heating or cooling needs for all zones in the building.
• Zone mode (Vacation OFF): Specific zones are conditioned only when demand comes from that zone. Each zone has its own thermostat. The individual zone thermostats only function when the control center is in zone mode.

2. Remote Vacation Switch (optional)

Switching the optional remote vacation switch to "Vacation ON" forces the system to act as a conventional central air conditioning and heating system. All zones will be controlled by the Zone 1 room thermostat, and all zone dampers will remain in the open position.

3. Emergency Heat Switch

When the Harmony III™ control center is used with a heat pump and the Emergency Heat switch is turned ON, the unit will satisfy all heating demands with electric backup heat. When the Emergency Heat switch is OFF, the heat pump is used for heating demands. (This switch has no effect on operation in a non-heat pump system, such as Option 1).

NOTE: Emergency Heat is usually more expensive to operate than Heat Pump heating. If equipped, use Emergency Heat only when necessary.

To turn off the Harmony III™ Zone Control System, either:

• Turn each thermostat to OFF, or
• Turn the master thermostat OFF and turn either vacation switch to "Vacation ON".

Switch Positions and Indicators:

• Vacation OFF: Enables individual zone control.
• Vacation ON: Conditions all zones simultaneously.
• Emergency Heat OFF: Allows the Heat Pump to provide heat.
• Emergency Heat ON: Forces auxiliary (backup) heat, disallowing the heat pump from providing heat.

Control Panel Indicators:

• Damper LEDs: Indicate when a damper to a specific zone is closed (no air permitted to that zone).
• Emergency Heat LED: Illuminates when the Emergency Heat switch is set to ON.
• Central Mode LED: Illuminates when only the Zone 1 thermostat is functional and controlling air to all zones.
• Operating Mode LEDs: Indicate the current operating mode.

How do I use the thermostat controls?

Whether in central mode (only Zone 1 thermostat is functional) or in zone mode (all thermostats are functional), thermostats operate as in a traditional, non-zoned system:

• HEAT setting: Tells the control center to provide heat to the zone(s) when needed.
• COOL setting: Tells the control center to provide cool air to the zone(s) when needed.
• AUTO setting: Allows either heating or cooling to occur based on the need. This setting is ideal for spring or autumn when temperatures vary throughout the day. Heating can come on in the morning, and cooling in the afternoon, if required.
• FAN AUTO or FAN ON: Controls blower operation. FAN AUTO allows the blower to turn on and off with heating/cooling needs. FAN ON runs the blower continuously. Zone-controlled dampers allow some zones to call for continuous fan (FAN ON) while others are set to FAN AUTO.

How do I use the central (Vacation) mode?

When central (Vacation ON) mode is selected, heating and cooling affect all zones.

1. Move the vacation switch on the zone control to VACATION ON (or, if used, move the remote vacation switch to "vacation on").
2. Choose HEAT, COOL, or AUTO on the master (Zone 1) thermostat.
3. Choose FAN AUTO or FAN ON on the master thermostat.
4. Set the master thermostat to the desired room temperature.

How do I use the zone mode?

When zone (Vacation OFF) mode is selected, heating and cooling are controlled by specific zone thermostats.

1. Move the Vacation switch on the control center to OFF.
2. Choose HEAT, COOL, or AUTO on each thermostat (thermostats need not be set alike).
3. Choose FAN AUTO or FAN ON on each thermostat (these settings may differ between zones).
4. Set thermostats to the desired room temperature.

How are zones determined?

Your Lennox dealer determines how rooms are sectioned into zones based on the following considerations:

1. Structural and Architectural Considerations

In multi-level houses with standard HVAC systems, heated air rises, causing upper floors to become too hot. Zoning remedies this by splitting the conditioned space into separate zones (e.g., 1st and 2nd floors). The 2nd floor temperature is then controlled by its own thermostat, independent of the 1st floor.

2. Climate Considerations

Exposure to sun and weather can create cold and hot spots in homes controlled by a single thermostat. Zoning mitigates this by grouping rooms with similar exposure into one zone. For example, rooms with northern exposure should not be zoned with rooms with southern exposure, as northern rooms may be too cool in winter while southern rooms may be too hot. To maintain balanced conditioned air, zones should contain rooms with similar weather exposure.

3. Occupancy Considerations

A single structure may contain different types of living spaces. Without zoning, it is difficult to condition all areas for everyone's comfort. Zoning allows the owner to control specific zones based on usage. Rooms used or occupied simultaneously are grouped together. For instance, bedrooms used primarily at night should not be zoned with a living room used only during the day or evening.

How do I use the optional Humiditrol® dehumidification accessory?

NOTE: If your zoned system is equipped with an optional Humiditrol dehumidification accessory, refer to the instructions provided with the Humiditrol Zoning Accessory manual (505,337M) for setting up zone control and thermostat operation.

Enabling and Disabling Humiditrol® using the ComfortSense™ 7000 Thermostat

NOTE: While this section describes enabling and disabling Humiditrol®, a simple way to prevent dehumidification during vacation (when the switch is set to "Vacation ON") is to set the thermostat's dehumidify setting as high as possible. To actively turn Humiditrol® on and off, follow these procedures:

NOTE: In INSTALLER SETTINGS, users can change both modes and setpoints. In USER SETTINGS, users can only change setpoints.

Disable Humiditrol (INSTALLER SETTINGS)

From the OPTIONS screen of the ComfortSense™ 7000 thermostat, select INSTALLER SETTINGS, scroll to HUMIDITY SETTINGS, and press ENTER. Then, press DEHUMIDIFY.

On the DEHUM MODE SETTING screen, use the arrows to select OFF and press ENTER.

Press the HOME tab to return to the HOME screen.

Enable Humiditrol and adjust dehumidification setpoint (INSTALLER SETTINGS)

From the OPTIONS screen, select INSTALLER SETTINGS. Scroll to HUMIDITY SETTINGS and press ENTER. Then, press DEHUMIDIFY.

On the DEHUM MODE SETTING screen, use the arrows to select HUMIDITROL and press ENTER.

Adjust the dehumidification setpoint, then press SAVE.

NOTE: When returning from vacation, ensure the vacation switch is returned to VACATION OFF (or ZONING ON).

Adjust dehumidification setpoint (USER SETTINGS)

From the OPTIONS tab, select USER SETTINGS, then select HUMIDITY SETTINGS and press ENTER. Press the box below DEHUMIDIFY.

Use the up/down arrows to change the humidity setpoint (between 45% and 60%); then press SAVE.

NOTE: If OFF was selected in installer settings for both humidify and dehumidify, the message "HUMIDITY MODES OFF" appears when HUMIDITY SETTING is pressed.

NOTE: If OFF was selected for DEHUMIDIFY but HUMIDIFY is ON in installer settings, the humidification menu appears. This setpoint adjustment has NO effect on dehumidification.

HUMIDITROL ADJUST is also available in user settings. The default is MAX dehumidification but can be changed to MID or MIN. Use arrows to scroll to MID or MIN, then press SAVE. This adjustment allows more (MAX) or less (MID, MIN) cooling beyond the cooling setpoint to meet the relative humidity level setpoint. Refer to the ComfortSense™ 7000 thermostat manual (506061-01) for more information about Humiditrol Adjust.

Owner Reminders and Maintenance

OWNER REMINDER!

Ensure the system installer has recorded the zoning information in Table 1 (on page 8) and identified a contact person and phone number for issues. If you have the optional Humiditrol® Enhanced Dehumidification Accessory (EDA) along with the Humiditrol® Zoning Accessory installed, request a copy of their installation and operation instructions.

Thermostat replacement

If a thermostat fails and requires replacement, be aware that not all thermostats are compatible with all systems. Certain thermostats, known as "power-robbing" thermostats, lack a "C" (common) wire connection terminal, which can cause unintended system operation and must not be used. Contact your Lennox dealer to identify and install a compatible thermostat with a "C" terminal.

Maintenance

Once your Lennox Harmony III™ Zone Control System is properly installed, no maintenance is required for the control panel's components. Only standard heating and cooling equipment (HVAC) maintenance is necessary.

If you experience problems with the system turning on for heating or cooling, it may be due to a programmed time delay, which typically expires within 5 to 20 minutes. These delays are normal and are built-in to ensure proper equipment operation.

Table 1. Homeowner's Zone Information Record

Lennox Dealer: _________________________

Contact: _________________________

Telephone Number: _________________________

Installation Date: _________________________