Your new White Rodgers 1F85-275 is a programmable/non-programmable thermostat with auto changeover for multi-stage/heat pump systems. It uses solid-state microcomputer technology for precise time/temperature control, with 5-1-1 day programming, 4 periods per day, simultaneous heat/cool storage, and features like filter reminder and keypad lockout. Compatible with 24V systems up to 1.5A per terminal. 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. Shut off electricity at main fuse box until installation complete. Label wires before disconnecting. This thermostat is for 24V systems only; not for millivolt or line voltage. Install away from drafts, direct sunlight, or heat sources for accurate sensing.
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.
ATTENTION! MERCURY NOTICE This product does not contain mercury. However, this product may replace a product that contains mercury. Mercury and products containing mercury must not be discarded in household trash. Do not touch any spilled mercury. Wearing non-absorbent gloves, clean up any spilled mercury and place in a sealed container. For proper disposal of a product containing mercury or a sealed container, refer to www.white-rodgers.com for location to send product containing mercury.
The thermostat consists of cover and base. Features LCD display showing time/room temperature alternating with set point, up/down arrows for adjustment, SYSTEM switch (COOL/OFF/HEAT/EMER), FAN switch (ON/AUTO), O/B switch for changeover (factory "O" for COOL energized). Terminals: R, C, Y, Y2, G, W/E, W2, O/B, L. Supports heat pump with/without aux/emergency heat, up to 2-stage heat/cool, heat-only/cool-only systems.
Applications:
| Description | Supported |
|---|---|
| Heat Pump (No Aux. or Emergency Heat) | Yes |
| Heat Pump (with Aux. or Emergency Heat) | Yes |
| Systems with up to 2 Stages Heat, 2 Stages Cool | Yes |
| Heat Only Systems (with optional fan switch) | Yes |
| Millivolt Heat Only Systems – Floor or Wall Furnaces | Yes |
| Cool Only Systems | Yes |
| Gas or Oil Heat | Yes |
| Electric Furnace | Yes |
| Hydronic (Hot Water) Zone Heat – 2 Wires | Yes |
| Hydronic (Hot Water) Zone Heat – 3 Wires | No |
CAUTION! To prevent electrical shock/equipment damage, disconnect power at main fuse/circuit breaker until installation complete. Label wires prior to disconnection.
WARNING! Do not use on circuits exceeding 20-30 VAC 50/60 Hz or DC (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.
CAUTION! Below 50°F, do not operate cooling (compressor damage). For electric heat/single-stage heat pump, set GAS/ELEC if fan energizes on heat call. For hydronic, clip W905 for longer cycles.
A standard heat/cool thermostat consists of three basic parts: 1. The cover, which may be either a snap-on or hinge type. 2. The base, which is removed by loosening all captive screws. 3. The switching subbase, which is removed by unscrewing the mounting screws that hold it on the wall or adapter plate. Before removing wires from old thermostat, label each wire with the terminal designation from which it was attached. Disconnect the wires from the old thermostat one at a time. Do not let wires fall back into the wall.
Remove packing from thermostat; gently pull cover off base. Set O/B switch to "O" (default) or "B" as needed. For slow cycle, clip W905; for Celsius, clip W904. Connect wires per diagrams. Place base over wall hole, mark/drill mounting holes, secure with screws (level for appearance). Push excess wire into wall, seal hole with fire-resistant material. Snap cover on.
Batteries: 2 AA alkaline (replace every 2 years; low battery shows "BATT"). Insert positive (+) to right. For unoccupied homes >3 months, replace if icon displayed. Offset occurs when <2 months life remains (±10°F); reset manually.
Terminal Designations:
| Terminal | Description |
|---|---|
| L | Heat pump malfunction indicator for systems with malfunction connection |
| O | Changeover valve for heat pump energized constantly in cooling |
| B | Changeover valve for heat pump energized constantly in heating |
| Y | Compressor Relay |
| Y2 | 2nd Stage Compressor |
| W/E | Heat Relay/Emergency Heat Relay (Stage 1) |
| W2 | 2nd Stage Heat (3rd Stage Heat in HP 2) |
| G | Fan Relay |
| RH | Power for Heating |
| RC | Power for Cooling |
| C | Common wire from secondary side of cooling system transformer or heat only system transformer |
| 6 | 3 Wire Zone Valve – Energized when no call for Heat |
Heat Pump Systems (Fig. 2): R to 24VAC hot, C to neutral, Y to compressor, G to fan, W2 to aux (stage 2), E to emergency, O/B to changeover (energized in COOL if "O"). Jumper for single aux both stages. CLASS II TRANSFORMER HOT 24VAC NEUTRAL 120VAC. NOTE: If your system does not provide an E connection, jumper W2 to E/W1 to use the Auxiliary Heat in the Emergency Mode.
Single Stage or Multi-Stage System (No Heat Pump) (Fig. 3): Similar wiring for non-heat pump systems, with notes on energized modes for Single Stage 1 (SS1) and Multi-Stage 2 (MS2).
CAUTION! Tighten securely; keep wires clear. Refer to equipment manuals for specifics.
To prevent static discharge problems, touch side of thermostat to release static build-up before touching any keys. Do not allow the compressor to run unless the compressor oil heaters have been operational for 6 hours and the system has not been operational for at least 5 minutes.
CAUTION! If at any time during testing your system does not operate properly, contact a qualified serviceperson.
If your system does not have a G terminal connection, skip to Heating System.
EMER bypasses the Heat Pump to use the heat source wired to terminal E on the thermostat. EMER is typically used when compressor operation is not desired, or you prefer back-up heat only.
To prevent compressor and/or property damage, if the outdoor temperature is below 50°F, DO NOT operate the cooling system.
The Thermostat Buttons and Switches
The Display
For Programmable Models Only:
Reset Operation Remove wires from R and C terminals (do not short), remove batteries for 2 minutes, reconnect. Display shows all segments on reset. Resets installer menu and programming to factory settings.
Comfort Alert Codes Monitors outdoor systems with Copeland Scroll compressors. Abnormal conditions shown by flashing ALERT codes on yellow LED:
Thermostat reacts by turning compressor off if Active Protection is ON.
General Troubleshooting
Factory Settings System Type: Single Stage (SS 1). Differential: Heat 0.6°F (single), 1.2°F (heat pump); Cool 1.2°F. Setpoint Range: 45°-90°F. Programming: Model-dependent (e.g., 5/1/1 Day for 1F85-275). All configurations reset to defaults on reset.