Nest Learning Thermostat Pro installation & configuration guide Need help? • Help online: http://support.nest.com/certified • Nest Certified Professional support: 1-855-VIP-NEST (1-855-847-6378) • Hours: 5am-9pm (pacific), 8am-midnight (eastern). Last updated: April 17, 2013 Version: 2.
Table of Contents Installation overview 1 What’s different about installing Nest 1 Installation check-list 1 Installation details 2 Technical specifications 4 Supported wiring 6 Wiring diagrams: Conventional Systems 8 Wiring diagrams: Heat Pump Systems 12 Wiring diagrams: Humidifiers and Dehumidifiers 15 Configuring Nest with Pro Setup 18 What is Pro Setup? 18 How do I enter Pro Setup? 18 How do I use Pro Setup? 18 How do you configure special systems? 19 How To Quick Reference G
Installation overview What’s different about installing Nest No jumper wires needed Discard any jumper wires on the old thermostat. Nest won’t need them. System Match Nest senses what wires are connected and asks you a few questions so it can offer different features specifically for your customer’s heating and cooling system. Pro Setup Pro Setup is an advanced setting to enable you to set up complex systems, including dual fuel systems humidifiers and dehumidifiers.
✓ Take advantage of the software update time. If there’s a software update available, Nest will start downloading it as soon as it connects to the Internet. The update can take as long as 10 minutes, so take this time to set your customer’s expectations about teaching Nest. ✓ Test heating and cooling for two minutes each. This is vital to any installation. After setting up Nest, you need to run each part of the system for a few minutes.
HVAC compatibility details Nest Learning Thermostat 2nd Generation HVAC–system Nest works with 95% of 24V systems: gas, compatibility electric, oil, forced air, heat pump & radiant. Heating: 1, 2 and 3 stages (W1, W2, W3) Cooling: 1 and 2 stages (Y1, Y2) Heat pump: with auxiliary and emergency heat (O/B, AUX, E) Fan (G) Power (C, Rh, Rc) Humidifier or dehumidifier (HUM, DEHUM) Available Y1 connectors Y2 G O/B Rc W1 W2/AUX C * (E/W3/HUM/DHUM) Rh Networking Wi-Fi recommended.
Technical specifications Nest Learning Thermostat 2nd Generation Sensors Temperature sensor +/- .5°F Humidity sensor +/- 3%RH Near-field activity sensor Far-field activity sensor Ambient light sensor Power Power sharing (with built-in rechargeable Li-ion battery, 7-10 year battery life) No external power required No common wire required with most installations Display 24 bit color 320 x 320 pixel display 1.
Nest Learning Thermostat 2nd Generation Display Mass = 215g / 7.6oz Diameter = 83.0mm / 3.27” Height = 28.0mm / 1.10” Base Mass = 37g / 1.3oz Diameter = 76.5mm / 3.01” Height = 10.7mm / 0.42” Assembled Mass = 215g / 7.6oz Diameter = 83.0mm / 3.27” Height = 32.0mm / 1.
Supported wiring Nest Learning Thermostat 2nd Generation Conventional connectors Heat pump connectors Y1 Stage 1 compressor relay Y1 Stage 1 compressor relay Y2 Stage 2 compressor relay Y2 Stage 2 compressor relay G Fan relay G Fan relay O/B Not used O/B Changeover valve relay Rc 24VAC power from cooling transformer* Rc Not used W1 Stage 1 heat relay W1 Stage 1 heat relay W2/AUX Stage 2 heat relay W2/AUX Auxiliary heat relay C 24VAC common wire. C 24VAC common wire.
Nest Learning Thermostat 1st Generation Conventional connectors Heat pump connectors Rh 24VAC power from heating transformer* Rh 24VAC power from heating transformer* W1 Stage 1 heat relay W1 Not usually used Y1 Stage 1 cooling compressor relay Y1 Stage 1 compressor contact G Fan relay G Fan relay C 24VAC common wire. C 24VAC common wire.
Wiring diagrams: Conventional Systems Conventional 1 stage heating Label Function Y1 Compressor Relay (Stage 1) Y2 Compressor Relay (Stage 2) G Fan Relay * O/B Heat Pump Changeover Valve Rc 24VAC power from cooling transformer W1 Heat Relay (Stage 1) W2/AUX Heat Relay (Stage 2)/Auxiliary Heat Relay C 24VAC Common Wire † * Star connector: W3, E, HUM, or DHUM Rh 24VAC power from heating transformer ‡ * Fan relay (G) is optional.
Conventional 3 stage heating Label Function Y1 Compressor Relay (Stage 1) Y2 Compressor Relay (Stage 2) G Fan Relay * O/B Heat Pump Changeover Valve Rc 24VAC power from cooling transformer W1 Heat Relay (Stage 1) W2/AUX Heat Relay (Stage 2)/Auxiliary Heat Relay C 24VAC Common Wire † * Star connector: W3, E, HUM, or DHUM Rh 24VAC power from heating transformer ‡ * Fan relay (G) is optional. However, without a G wire, Nest will not be able to control the fan independent of heating.
Conventional 2 stage heating and 1 stage cooling Label Function Y1 Compressor Relay (Stage 1) Y2 Compressor Relay (Stage 2) G Fan Relay * O/B Heat Pump Changeover Valve Rc 24VAC power from cooling transformer W1 Heat Relay (Stage 1) W2/AUX Heat Relay (Stage 2)/Auxiliary Heat Relay C 24VAC Common Wire † * Star connector: W3, E, HUM, or DHUM Rh 24VAC power from heating transformer ‡ * Fan relay (G) is optional.
Conventional 3 stage heating and 2 stage cooling Label Function Y1 Compressor Relay (Stage 1) Y2 Compressor Relay (Stage 2) G Fan Relay * O/B Heat Pump Changeover Valve Rc 24VAC power from cooling transformer W1 Heat Relay (Stage 1) W2/AUX Heat Relay (Stage 2)/Auxiliary Heat Relay C 24VAC Common Wire † * Star connector: W3, E, HUM, or DHUM Rh 24VAC power from heating transformer ‡ * Fan relay (G) is optional.
Wiring diagrams: Heat Pump Systems 1 stage heat pump Label Function Y1 Compressor Relay (Stage 1) Y2 Compressor Relay (Stage 2) G Fan Relay * O/B Heat Pump Changeover Valve Rc 24VAC power from cooling transformer W1 Heat Relay (Stage 1) W2/AUX Heat Relay (Stage 2)/Auxiliary Heat Relay C 24VAC Common Wire † * Star connector: W3, E, HUM, or DHUM Rh 24VAC power from heating transformer ‡ * Fan relay (G) is optional.
1 stage heat pump with aux heat and emergency heat Label Function Y1 Compressor Relay (Stage 1) Y2 Compressor Relay (Stage 2) G Fan Relay * O/B Heat Pump Changeover Valve Rc 24VAC power from cooling transformer W1 Heat Relay (Stage 1) W2/AUX Heat Relay (Stage 2)/Auxiliary Heat Relay C 24VAC Common Wire † * Star connector: W3, E, HUM, or DHUM Rh 24VAC power from heating transformer ‡ * Fan relay (G) is optional.
2 stage heat pump with aux heat Label Function Y1 Compressor Relay (Stage 1) Y2 Compressor Relay (Stage 2) G Fan Relay * O/B Heat Pump Changeover Valve Rc 24VAC power from cooling transformer W1 Heat Relay (Stage 1) W2/AUX Heat Relay (Stage 2)/Auxiliary Heat Relay C 24VAC Common Wire † * Star connector: W3, E, HUM, or DHUM Rh 24VAC power from heating transformer ‡ * Fan relay (G) is optional. However, without a G wire, Nest will not be able to control the fan independent of heating.
Wiring diagrams: Humidifiers and Dehumidifiers The 2nd generation Nest LearningThermostat is compatible with most whole home humidifier and dehumidifier systems that connect to your thermostat with one or two low voltage wires.
Possible configurations: Stand Alone Humidifier, 1 Wire • • • • This system has a humidifier that is separate from the HVAC system. Install the hum wire directly into the * terminal at Nest. Correctly ground the other wire from the Humidifier. No relay is recommended. Stand Alone Humidifier, 2 Wire • • • • This system has a humidifier that is separate from the HVAC system. Install the 2 hum wires directly into the relay. Run the single wire from the relay to the * terminal at Nest.
Built-in Humidifier System, 2 Wire • • • • This system has a humidifier built in to its HVAC system and 2 separate hum wires. Install the 2 hum wires directly into the relay Run the single wire from the relay to the * terminal at Nest. Nest recommends the White Rogers 90-290Q or similar 24VAC HVAC relay. Built-in Humidifier System, 1 Wire • This system has a humidifier built in to its HVAC system and only 1 hum wire. • Connect the hum wire from the built-in system directly to the * terminal at the Nest.
Configuring Nest with Pro Setup Pro Setup lets installation professionals quickly configure the way Nest controls an HVAC system. Complex systems such as dual fuel systems, humidifiers and dehumidifiers require Pro Setup. Nest recommends professional installation to homeowners with these systems. Pro Setup can be used the first time you set up Nest or anytime through the SETTINGS menu. What is Pro Setup? Pro Setup allows HVAC technicians to configure how Nest controls your system.
throughout the home). Depending on the wire configuration, the Source or Delivery settings may have only one default option. Source options include: • Gas • Electric • Oil • Propane (LP) • Geothermal Delivery options include: • Forced air • In-floor radiant • Radiators It's recommended that all connectors highlighted in yellow be reviewed to ensure that the options chosen are right for that system. However, you can turn the ring and select DONE at any time to exit Pro Setup without making any changes.
Humidifiers and Dehumidifiers The 2nd generation Nest Learning Thermostat supports wholehome humidifiers and dehumidifiers. There are multiple Pro Setup settings for the * wire to control a humidifier or dehumidifier. All wire Types include a Fan setting to specify whether or not the fan should be activated when humidification or dehumidification is engaged. Humidifier Pro Setup will show an Activate setting to specify whether heat needs to be activated for humidification to turn on.
How To Quick Reference Guide Action Steps Configuring Nest for the installation location and HVAC system Just after installation, Nest will guide you through a set up interview, where you will configure it for the heating and cooling system it’s controlling and for the home or business where it’s installed. To help with HVAC configuration, Nest mechanically and electrically detects the wires inserted into its press connectors.
Action Steps Testing second stage or auxiliary Conventional heating heat after installation Before Nest has activated Time-to-Temperature, second stage heat will turn on when the setpoint is 4°F or greater than the room’s ambient temperature. Heat Pumps Auxiliary heat will turn on when the setpoint is 4°F and the outdoor temperature is below 50°F, the default auxiliary heat lockout temperature.
Action Steps Adjust Away Heating and Cooling Temperatures These temperatures are set as the final step during the set up interview. But if Nest is already configured, here are the steps: 1. Press the ring to bring up the menu. 2. Turn the ring and select SETTINGS. 3. Turn the ring and select AWAY. Turn the ring to set the HEAT TO temperature. Press the ring to set the COOL TO temperature. Press the ring again when done.
Wiring error quick reference guide When Nest senses what wires have been connected to its base, it automatically configures its software for the system type it detects. If it’s a heat only system, Nest won’t show any cooling options. If it’s a heat pump, Nest will know—and do a special test to check the orientation of the O/B wire. If Nest senses a problem with the wiring, you’ll get an error if the issue must be fixed before setup can continue, or a note if it is not critical to fix during setup.
Error number Description What’s going on? No power to Y1wire detected. Your Nest is physically detecting a wire in the Y1 connector but isn’t detecting any power to it. Heat pump wireO/B detected. No heat pump system present. Your Nest is physically detecting a wire in the O/B connector but isn’t detecting any power to it. Heat pump can have at most one auxiliary heat wire.
Error number Description What’s going on? Your Nest may have tripped an internal fuse and Nest needs to be replaced. Your Nest either has wires that aren't fully inserted into the connectors or has tripped an internal fuse. Power wire Rc detected. Not connected to equipment. Your Nest isn’t electrically detecting your Rc wire, but one is connected to the Nest base. Power wire Rh detected. Not connected to equipment.
Error number Description What’s going on? W2 Failed to connect. Your Wi-Fi access point may have security settings enabled that prevent your Nest from connecting. W3 Failed to connect. Your Wi-Fi access point is not providing a network IP address to your Nest. W4 Failed to connect. Nest is connected to your wireless network but not to the internet. Important Note: These errors may change with future software updates. Visit nest.com/support for the latest information.
Troubleshooting Handling unusual thermostat wiring When a B or X wire is a common wire Most thermostat manufacturers use C to designate the connector for the common wire. However there are some Trane, American Standard, and York thermostats use B for the common wire. The NEMA standard designated the B wire as one of the change-over wires for some heat pump manufacturers. This is a simple issue to address: 1.
What if Nest isn't getting enough power from W or Y and the consumer doesn't have a Common (“C”) wire installed? While we find that in the vast majority of homes Nest can charge its built in battery power sharing from the regular heating and cooling wires, a few installations require a common wire to bring power to Nest without interfering with the normal operation of the heating and cooling system.
Heat only systems Heating and cooling systems The heat call is detected by the controller board when the W wire is shorted to the R wire, which causes the 24V AC voltage to be detected. When the Nest thermostat is taking power, a small voltage is generated between W and C (typically less than 8 volts) which can cause a false heat call in a small number of systems.
Quick Troubleshooting Reference Guide Symptom What’s going on Steps to fix Nest doesn’t turn The internal battery is low and on after needs to charge. installation. Red LED blinking on front. If you leave it where it is, it will slowly charge and eventually turn on. This can take an hour or two. If you have a mini-USB cable and wall charger you can charge it more quickly over USB. You need to restart or reset the settings on the thermostat.
Symptom What’s going on Steps to fix Your customer is seeing a question mark on their Nest when they use one of the Nest apps. The Nest apps will show a question mark over the thermostat when the Nest servers can’t communicate with the device. This may happen if: • The customer’s Internet Service Provider is down. • The customer’s router is incompatible with Nest. • The Nest servers are down or undergoing maintenance.
