The White Rodgers 1F62-21 is a low voltage setback thermostat designed for 24V AC heat/cool and heat-only systems. It features automatic temperature setback for energy efficiency, one-finger operation with LCD display, and minimum cycle timing. Powered by 24V transformer with battery backup. Below are the key specifications, installation, operation, and troubleshooting instructions.
Assemble tools: Screwdriver, wire strippers, level. Disconnect 120V AC power before installation. Ensure wiring is 24V AC; if unsure (millivolt, line, or low voltage), have it inspected by a qualified professional. Install away from drafts, dead air spots, doors, or corners for accurate sensing. Meets HUD requirements and energy efficiency standards.
This setback thermostat provides automatic temperature setback for comfort and energy savings. Features one-finger operation with LCD display, minimum 6-minute cycle timing for heat/cool. Powered by 24V transformer; two 1.5V watch batteries maintain operation during outages. Components: Base/cover, system switch (Cool-Off-Heat), fan switch (heat/cool), setback switch (0°F/5°F/10°F/15°F), temperature slide, time set button, differential switch (preset 1°F), gas/electric switch.
WARNING! Do not use on circuits exceeding 24V AC; higher voltage can damage thermostat or cause shock/fire. Disconnect power before installation/maintenance. For two-transformer systems, ensure proper phasing/grounding; otherwise, cannot be used. Qualified service person required for resistor installation or fuse replacement.
CAUTION! Omit air conditioner test if outdoor temperature below 40°F. Do not connect resistor to R terminal or furnace to avoid damage. Short battery life may result from airflow issues, power interruptions, or system type (e.g., Bryant, Payne furnaces).
Disconnect 120V AC power. Remove old thermostat cover, note/label wires (Y, W, R, etc.), remove base.
Option Switches: Differential to 1°F (default); Gas/Electric for system type; Temperature Unit to °F/°C.
2-Wire Heat-Only: W (heat) to W, R (power) to R; 120V AC transformer.
4-Wire Heat/Cool: W (heat) to W, Y (cool) to Y, G (fan) to G, R (power) to R; 120V AC transformer.
Cooling System: Y (cool) to Y, G (fan) to G, R (power) to R.
Heating System: W (heat) to W, G (fan) to G (if applicable), R (power) to R.
Note: For two-transformer systems, verify grounding/phasing.
Display shows time, temperature, system status, setback mode. Use time set button for adjustments (1-minute increments). Temperature slide sets desired temp. System switch: Cool/Off/Heat. Fan: Auto (cycles with system) or On (continuous).
Testing: Set to Off (no display/fan); Cool 5°F above room (A/C activates in 2 min, omit <40°F); Heat 5°F above room (furnace activates).
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| No Display | Miswired or no voltage | Check 20-24V AC between R/W; inspect limit switch |
| Heating Not Working | Not in Heat mode, not calling for heat, faulty components (e.g., gas valve), blown fuse | Set to Heat, raise temp; check/replace fuse; verify wiring |
| Cooling Not Working | Not in Cool mode, not calling for cool, setback active, miswired | Set to Cool, lower temp; disable setback; check wiring |
| Short Battery Life | Airflow issues, power interruptions, system type (e.g., Carrier furnaces) | Install 1K, 0.5W resistor (qualified person required) |
Fuse Replacement: Check/correct wiring; replace if miswired/overloaded. Resistor Installation: Methods 1-3 for heat/cool or heat-only; qualified service person required. Contact technical service: 1-314-577-1300 or 1-800-876-TECH (8:00 AM-4:30 PM CST) if unresolved.