White Rodgers 775 User Manual

The White Rodgers 775 is a 7-day programmable electronic digital thermostat for low voltage heating and cooling systems, compatible with single-stage heat/cool, heat-only, cool-only, millivolt, gas/oil/electric furnaces, and hydronic zone heat. It features 7-day programming with 4 periods per day, automatic/manual changeover, battery backup (2 AAA batteries), and adjustable cycle rates. Powered by 24 VAC; compatible with systems up to 1.5A per terminal, 1.5A max total. Below are the key specifications, installation, operation, programming, and troubleshooting instructions.

Preparations

Assemble tools: hand or power drill with 3/16 inch drill bit (if needed), flat blade screwdriver, wire cutter/stripper, level. Shut off electricity at main fuse box until installation complete. Label wires before disconnecting. This thermostat is for 24V systems only; not for line voltage. Install away from drafts, direct sunlight, or heat sources for accurate sensing. Install 2 AAA alkaline batteries before programming.

WARNING! Failure to read and follow all instructions carefully before installing or operating this control could cause personal injury and/or property damage. Save these instructions.

Description

The thermostat uses solid-state microcomputer technology to provide precise time/temperature control. Features 7-day programming with four time/temperature settings per day, simultaneous heat/cool programs, automatic changeover (selectable), compressor protection, fan auto/on, backlit LCD display, °F/°C convertibility. LCD display shows time/room temp/setpoint, up/down arrows, SYSTEM switch (HEAT/OFF/COOL/AUTO), FAN switch (ON/AUTO). Terminals: R (hot), C (common), G (fan), Y (compressor), W (heat).

Applications: Single-Stage Heat/Cool: Yes; Heat Only: Yes; Cool Only: Yes; Millivolt: Yes; Gas/Oil/Electric/Hydronic: Yes.

Precautions

CAUTION! To prevent electrical shock/equipment damage, disconnect power at main fuse/circuit breaker until installation complete. Label wires prior to disconnection. If in doubt about wiring, consult qualified heating/air conditioning contractor.

WARNING! Do not use on circuits exceeding 17-30 VAC 50/60 Hz (0.05-1.5A per terminal, 1.5A max total); higher voltage damages control/causes shock/fire. Do not short terminals on gas valve/primary control to test; short/incorrect wiring burns out components/causes injury/property damage. Conform to NEC Class II circuits. Do not operate cooling below 50°F (compressor damage).

ATTENTION! This product does not contain mercury but may replace one that does. Do not open mercury cells; if damaged, wear non-absorbent gloves, clean up spilled mercury, place in sealed container. Refer to www.thermostat-recycle.org for disposal. Handle to avoid static discharge.

Specifications

• Electrical: 17-30 VAC 50/60 Hz, NEC Class II; Terminal Load 0.05-1.5A per terminal, 1.5A max total.
• Batteries: 2 AAA alkaline (backup).
• Setpoint Range: 45°F to 90°F (7°C to 32°C).
• Operating Ambient: 32°F to 105°F (0°C to 41°C).
• Humidity: 90% non-condensing max.
• Shipping: -40°F to 150°F (-40°C to 65°C).
• Dimensions: Approx. 3-1/2”H x 5-1/2”W x 1-1/8”D.
• Other: 7-day programming with 4 periods/day; Compressor lockout 5 min.

Removing Old Thermostat

A standard heat/cool thermostat consists of three basic parts: 1) Cover; 2) Base; 3) Subbase. Label each wire with terminal designation before disconnecting. Disconnect wires one at a time; do not let fall into wall.

Installation

Remove old thermostat. Mount new base level on wall, connect wires to terminals. Push excess wire into wall, secure base, attach thermostat body. Power up and configure.

Batteries: Install 2 AAA alkaline; low battery indicated on display.

Wiring Diagrams

Terminal Designations: R (24V hot), C (common), Y (compressor), G (fan), W (heat).

Single Stage Heat/Cool: R to hot, C to common, Y to compressor, G to fan, W to heat.

Heat Only: R to hot, W to heat.

Cool Only: R to hot, Y to compressor, G to fan.

Millivolt: W to millivolt gas valve.

CAUTION! Refer to equipment manuals for specifics. Do not short wires.

Check Operation

Restore power. Set SYSTEM to HEAT/COOL, FAN to ON/AUTO, adjust setpoint to test.

Fan Operation

1. FAN ON: Blower runs continuously.
2. FAN AUTO: Blower runs on call for heat/cool.

Heating System

1. SYSTEM HEAT.
2. Setpoint above room temp: Heat activates.
3. Setpoint below: Heat stops.

Emergency System

1. Not applicable for single-stage.

Cooling System

CAUTION! Do not operate below 50°F.

1. SYSTEM COOL.
2. Setpoint below room temp: Cool activates.
3. Setpoint above: Cool stops.

Operating Features

• Home Screen: LCD shows time/temp/setpoint, alternates; icons for system on, hold, battery.
• Key Features: Automatic changeover, preprogrammed schedules, short-cycle protection, temporary override, indefinite hold, °F/°C, adjustable cycle rates.
• Compressor Protection: 5-min lockout.
• Range Limits: 45-90°F.

Programming

7-day programming with 4 periods per day. Factory preprogrammed; press RUN to start.

1. Set Time/Day: Press TIME, adjust hour/min, DAY for day.
2. Program: Select HEAT/COOL, press PROGRAM for period, TIME/TEMP to set.
3. Copy: Hold COPY to duplicate.
4. Review: Press PROGRAM to cycle.
5. Run: Press RUN.
6. Hold: Press HOLD for permanent; temporary override.

Factory Heat: Weekdays 6AM 70°F, 8AM 62°F, 5PM 70°F, 10PM 62°F; Weekends 6AM 70°F, 10PM 62°F. Cool: Similar with 78°F, 85°F, 78°F, 82°F.

Installer Configuration

Press HOLD + RUN for 5 seconds to enter menu. Use UP/DOWN to adjust, HOLD to advance.

Troubleshooting