The White Rodgers P150 is a programmable line voltage thermostat for electric heating systems such as baseboards, convectors, or aeroconvectors. It maintains room temperature at the set point with high accuracy, supporting resistive loads up to 18A (2400W at 120V, 4800W at 240V). Features 7-day programming with 4 events per day, Day/Night modes, optional Automatic mode for cycling, Celsius/Fahrenheit display, and short cycle protection. Below are the key specifications, installation, operation, programming, and troubleshooting instructions.
Assemble tools: screwdriver, wire stripper. Shut off electricity at main fuse box until installation complete. Label wires before disconnecting. This thermostat is for line voltage electric heating units only (120/240 VAC resistive loads); not for low voltage or inductive loads. Install away from drafts, direct sunlight, or heat sources for accurate sensing. No batteries required.
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 is a programmable line voltage control for electric heating, with 7-day scheduling for 4 events per day. It cycles the heating load on/off based on digital sensing. Knob or buttons for setpoint adjustment; modes: Day/Night, Automatic cycling optional. LCD shows time/temp/setpoint, programming menu.
Applications: Electric Heating: Baseboard, Convector, Aeroconvector; Voltage: 120/240 VAC; Resistive Loads Only.
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 electrician.
WARNING! Do not use on circuits exceeding 120/240 VAC 50/60 Hz, 18A resistive; higher voltage or inductive loads damages control/causes shock/fire. All wiring must conform to local/national electrical codes. Do not use on low voltage systems.
Shut off power. Remove old thermostat cover. Label wires before disconnecting. Disconnect wires one at a time; do not let fall into wall. Remove old base from wall.
Remove old thermostat. Mount new base level on wall using screws. Connect wires to terminals (no polarity for line voltage). Push excess wire into wall, secure base, attach thermostat cover. Power up and configure programming.
Terminal Designations: L1 (Hot), L2 (Load).
240 VAC: Connect L1 to power hot, L2 to heater load.
120 VAC: Connect L1 to hot, L2 to load, neutral to heater.
CAUTION! All wiring must conform to local/national electrical codes. Use CO/ALR connectors for aluminum wiring.
Restore power. Adjust setpoint above room temperature to test heating.
Not applicable; heating-only thermostat without fan control.
Not applicable; use circuit breaker for shutdown.
Not applicable; heating-only thermostat.
7-day programming with 4 events per day. Factory preprogrammed; enter menu to customize.
Enter installer menu by holding HOLD + DOWN for 5 sec. Adjust cycle rates, lockout settings, short cycle protection.
| Setting | Default | Options | Comments |
|---|---|---|---|
| Cycle Rate | Fast | Fast/Slow | For different systems |
| Short Cycle Protection | 5 min | Off/5 min | Prevents compressor short cycles |
| Lockout | Off | On/Off | Keypad lock |
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Heater not turning on | Knob set too low, power off, wiring issue. | Adjust knob above room temp; check power and wiring. |
| Heater runs continuously | Stuck contacts, faulty bimetal. | Inspect for damage; replace thermostat. |
| Erratic operation | Loose wires, damaged sensing element. | Tighten connections; avoid distorting bimetal. |
| Overheating | Short cycle or load issue. | Check differential (3°F); ensure non-inductive load. |