The White Rodgers 875 is a 5+1+1 day programmable electronic digital thermostat for low voltage heating and cooling systems, compatible with multi-stage heat/cool, heat pumps (with/without aux/emergency heat), heat-only, cool-only, millivolt, gas/oil/electric furnaces, hydronic zone heat, and central air conditioning. It features 5+1+1 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 2 stages heat/2 stages cool, 1.5A per terminal, 2.5A max total. Below are the key specifications, installation, operation, programming, and troubleshooting instructions.
Assemble tools: hand or power drill with 3/16 inch drill bit (if needed), flat blade screwdriver, wire cutter/stripper, level, voltmeter. 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.
The thermostat uses solid-state microcomputer technology to provide precise time/temperature control. Features 5+1+1 day programming with four time/temperature settings per day, simultaneous heat/cool programs, up to 2 stages heat/2 stages cool, 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/EMER), FAN switch (ON/AUTO). Terminals: R (hot), C (common), G (fan), Y1/Y2 (compressor stages), W1/W2 (heat stages), O/B (changeover).
Applications: Multi-Stage Heat/Cool: Yes; Heat Pump with Aux/Emergency: Yes; Single-Stage: Yes; Heat Only: Yes; Cool Only: Yes; Millivolt: Yes; Gas/Oil/Electric/Hydronic: Yes.
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, 2.5A 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.
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.
Remove old thermostat. Mount new base level on wall, connect wires to terminals. For single transformer systems, install red jumper between RH and RC if needed. Push excess wire into wall, secure base, attach thermostat body. Power up and configure.
Batteries: Install 2 AAA alkaline before programming; low battery flashes "BATT". Replace if flashing; program retained.
Terminal Designations: R (hot), C (common), G (fan), Y1/Y2 (compressor stages), W1/W2 (heat stages), O/B (changeover).
Multi-Stage Heat/Cool: R to hot, C to common, Y1/Y2 to compressor stages, W1/W2 to heat stages, G to fan.
Heat Pump: Y1/Y2 compressor, O/B changeover (O cool, B heat), W1/W2 aux heat.
CAUTION! RED jumper between RH and RC for single transformer systems. Refer to equipment manuals for specifics.
Restore power. Set SYSTEM to HEAT/COOL, FAN to ON/AUTO, adjust setpoint to test.
CAUTION! Do not operate below 50°F.
5+1+1 day programming with 4 periods per day. Factory preprogrammed; press RUN to start.
Factory Heat: M-F 6AM 70°F, 8AM 62°F, 5PM 70°F, 10PM 62°F; Sa/Su 6AM 70°F, 10PM 62°F. Cool: M-F 6AM 78°F, 8AM 85°F, 5PM 78°F, 10PM 82°F; Sa/Su 6AM 78°F, 10PM 82°F.
Press HOLD + RUN for 5 seconds to enter menu. Use UP/DOWN to adjust, HOLD to advance.
| Menu Item | Default | Options | Comments |
|---|---|---|---|
| Changeover | AUTO | AUTO/MAN | Auto changeover |
| Anticipation Heat | 2 | 2-40 | Heat cycle rate |
| Anticipation Cool | 4 | 4-40 | Cool cycle rate |
| °F/°C | °F | °C | Temperature scale |
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Display Blank | Power loss. | Check transformer/wiring; restore power. |
| BATT Flashing | Low battery. | Replace 2 AAA batteries. |
| System Not Responding | Wiring error. | Verify wiring, circuit breaker. |
| Short Cycling | Cycle rate setting. | Adjust in menu. |
| Compressor Won't Start | 5-min lockout. | Wait; check indicators. |