RT4 Manual Changeover Non-Programmable Hardwired Non-Programmable Electronic Thermostat • For use with Friedrich PTAC and Vert-I-Pak Systems • 30-Minute Power Loss Memory Retention Installation, Operation & Application Guide
Table of Contents Parts Diagram........................................................................................................................................... 1 Specifications ........................................................................................................................................... 2 Important Safety Information .................................................................................................................. 2 Package Contents/Tools Required ....
Parts Diagram Celsius/ Fahrenheit Jumper Heat Pump/ Non-Heat Pump Jumper F–C NON–HP HP Gas Electric Reset Button Auto Cool Mode Switch Off Gas/Electric Switch On Heat Fan Switch 1
Specifications Input: • Voltage: 18-30 VAC Output: • Maximum: 1 amp per terminal (3 amp total for all terminals) Temperature Ranges: • Temperature control range: 45°F to 90°F (7°C to 32°C) Accuracy: ± 1°F (± 0.5°C) • Differential range: 1°F to 3°F (0.5°C to 1.5°C) Accuracy: ± 1°F (± 0.
Package Contents/Tools Required Package includes: RT4 non-programmable thermostat on base, thermostat cover, wiring labels, screws and wall anchors, Installation, Operation and Application Guide. Tools required for installation: Drill with 3/16” bit, hammer, screwdriver.
To Remove Existing Thermostat ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse or switching the appropriate circuit breaker to the OFF position before removing the existing thermostat. 1. Turn off power to the heating and cooling system by removing the fuse or switching off the appropriate circuit breaker. 2. Remove cover of old thermostat. This should expose the wires. 3. Label the existing wires with the enclosed wire labels before removing wires.
To Install Thermostat (continued) 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. Put thermostat base against the wall where you plan to mount it (Be sure wires will feed through the wire opening in the base of the thermostat). Mark the placement of the mounting holes. Set thermostat base and cover away from working area. Using a 3/16” drill bit, drill holes in the places you have marked for mounting. Use a hammer to tap supplied anchors into mounting holes.
Replacing Wiring Labels Replace the old labels with the enclosed new labels: 6 Old New F, G G Type Fan control relay B B Heat active reversing valve Y, Y6 Y Cooling control H, W, 4 W Heating control C C Transformer, common side M, 4, RH, RS, R R Transformer, hot side
Operation Setting the Room Temperature (Setpoint Temperature) Step 1: Press the or button; the current temperature setpoint displays. Step 2: Press the or button until the desired temperature setpoint displays. The new temperature setting is automatically saved. After 5 seconds, the display returns to showing the current room temperature. Setting a New Temperature Differential The default temperature differential is 1°. When your room temperature varies by 1°F, the thermostat turns on your system.
A Quick Test caution!: Do not switch system to cool if the outdoor temperature is below 50°F (10°C). This can damage the air conditioning system and may cause personal injury. Action: Set the Mode switch to Cool. Press the button until the temperature setting is 3°F below the room temperature. Result: The A/C system and fan should turn on. Action: Set the Mode switch to Off. Result: The A/C should turn off (there may be a fan delay). Action: Set the Mode switch to Heat.
Wiring Diagram HARDWIRED F R I E D R I C H P T A C C C R R W W Y Y B B O G G T H E R M O S T A T NOTE: B terminal used on heat pump models only 9
Troubleshooting Symptom The system is not turning on Remedy Check the wiring (see Installation, Page 4) LCD is blank Check the wiring (see Installation, Page 4) Thermostat is not properly controlling the fan Check that the Gas/Electric switch is set to electric Thermostat is continuously turning on and off Increase the temperature differential (see Setting a New Temperature Differential, Page 7) Temperature display is not accurate Your thermostat has two options for temperature readout: Fahrenheit
Friedrich Air Conditioning Co. Post Office Box 1540 • San Antonio, Texas 78295-1540 4200 N. Pan Am Expressway • San Antonio, Texas 78218-5212 (210) 357-4400 • FAX (210) 357-4480 www.friedrich.
