Using 360° Viewing:
- Rotate: Use top-to-bottom, side-to-side by use of mouse arrow.
- Zoom In: Double click on image.
- Zoom Out/Reset: Put photo at full zoom & then double click.
Low Voltage Thermostat, Stages Cool 2, Stages Heat 4
- Item # 1RZY2
- Mfr. Model # YTH9421C1002
- UNSPSC # 41112209
- Catalog Page # N/A
- Shipping Weight 1.5 lbs.
- Item Low Voltage Thermostat
- Stages Heat 4
- Stages Cool 2
- Temp. Settings per Day 4
- Programs per Week 7
- Terminal Designations R, RC, RH, C, W1, W2, W3, Y, Y2, G, L, 1, 2, 3, Out1, Out2, In1, In2, Dats1, Dats2, Hum1, Hum2, Dhm1, Dhm2, Vnt1, Vnt2
- System Switching Auto-Heat-Cool-Off-Emergency
- Fan Switching Auto-On-Circulate
- Display Type LCD, Backlit
- Key Pad Lockout Yes
- Programmable Fan Yes
- Humidification Control Yes
- Remote Sensing Capability Yes
- Battery Backup No
- Low Battery Indicator No
- Dual Transformer Compatible Yes
- Power Method Hardwired
- Voltage 24VAC
- Height 4-9/16"
- Width 6"
- Depth 1-3/8"
- Color White
- Control Range Heat 40 Degrees to 90 Degrees F, Cool 50 Degrees to 99 Degrees F
- Features Touch Screen selectable 7 Day or Nonprogrammable, 3 Heat/2 Cool Conventional or 4 Heat/2 Cool Heat Pump System, Humidification, Dehumidification and Ventilation Control with 3 Wires to Thermostat
- For Use With Module or EnviraZONE panel
- Includes Thermostat and Interface Module
- Green Environmental Attribute Product Contributes to Reducing Energy Consumption
Compliance and Restrictions
Green Product - This item has been designated by the manufacturer as an environmentally preferable product (EPP) because this item has one or more environmentally preferable attributes. For additional information, see the Tech Specs tab on the product description page.
Item # 1UHG7DAYTON
Price $210.25 / each
Item # 2NY19WHITE-RODGERS
Price $75.85 / each
Item # 1AYR8HONEYWELL
Price $163.75 / each
Item # 6WY10HONEYWELL
Price $99.35 / each
Item # 3MY13WHITE-RODGERS
Clearance Price $109.67 / each
Price $121.85 / each
Item # 34GR15HONEYWELL
Price $297.50 / each
Item # 6WY11HONEYWELL
Price $108.75 / each
Item # 3MY14WHITE-RODGERS
Price $88.15 / each
Item # 6WY12HONEYWELL
Price $127.60 / each
Item # 6WY18HONEYWELL
Price $363.00 / each
Item # 6WY13HONEYWELL
Price $138.50 / each
Item # 1AYR6HONEYWELL
Price $333.50 / each
Alternate Search Terms
- Temperature Controls (931)
- Heating/Cooling Controls (491)
- Heating/Cooling Thermostats (315)
- Digital Thermostats (277)
- Low-Voltage Thermostats (209)
- Residential Thermostats (188)
- Programmable Thermostats (164)
- Electronic Thermostats (155)
- Wall Thermostats (144)
- Heat Pump Thermostats (118)
- Multistage Thermostats (103)
- Microelectronic Thermostats (87)
- Touchscreen Thermostats (25)
- Universal Thermostats (25)
Product Reviews Disclaimer:
Grainger is neither responsible for, nor does it endorse, the content of any product review or statement posted. Any statements posted constitute the statements of the poster and are not the statements of Grainger. The statements posted by Grainger employees with the Grainger employee badge represent the views of such employees and are not the statements of Grainger. Grainger makes no representations as to the appropriateness, accuracy, completeness, correctness, currentness, suitability, or validity of any product review or statements posted, including those posted by employees with the Grainger employee badge, and is not liable for any losses, injuries or damages which may result from any such product review or statements. Use of any linked web site provided in a product review or post is at the user's own risk.
Ask your questions. Share your answers.
The EIM is where the actual control wires for the system get attached. From the EIM to the thermostat there are 3 wires, two are for power with the third being for communication between the thermostat and the EIM.
The YTH9421C1002 is an ideal device when upgrading to a multistage system that would require more wires going to the thermostat than currently exist or you are in a situation where you cannot pull additional wires to the thermostat.
Ask and Answer Disclaimer:
Grainger is neither responsible for, not does it endorse, the content of any statement posted. Any statements posted constitute the statements of the poster and are not the statements of Grainger.
The statements posted by Grainger employees with the Grainger employee badge represent the views of such employees and are not the statements of Grainger. Grainger makes no representations as to the appropriateness, accuracy, completeness, correctness, currentness, suitability, or validity of any statements posted, including statements posted by employees with the Grainger employee badge, and is not liable for any losses, injuries or damages which may result from any such statements.
Use of any linked web site provided in a post is at the user's own risk. This site should not replace the use by you of any technical product manual or other professional resource or adviser available to you.
The source for the answers given by Grainger in Ask and Answer are based on the information provided with the question, which may not be complete or may not apply to other situations, and based on product literature and informational materials, the content of which is provided by Grainger's product suppliers. Grainger disclaims liability for any information it provides in Ask and Answer which later may be alleged or determined by a court of law to be inaccurate or incorrect.
The answers given by Grainger in Ask and Answer are not intended to replace or supplement any professional, engineering or other consultation services available to its product users. Always read, understand, and follow the product information and instructions provided by the manufacturer. same on category AAA as well