Installation: 1source S1-THEC11P5S Programmable Thermostat Instruction Manual

Content

Overview

The S1-THEC11P5S Programmable Thermostat is a backlit digital thermostat for residential heating and cooling systems. Its 5+2-day schedule supports separate weekday and weekend temperature programming, while the system and fan switches provide direct control during everyday operation.

This thermostat is intended for compatible single-stage HVAC applications, including many gas, electric, millivolt, and heat pump systems. It supports one stage of heating and one stage of cooling, but heat pump installations must not require auxiliary or emergency heat control.

Specifications

Model: S1-THEC11P5S
Thermostat type: 5+2-day programmable digital thermostat
System capacity: 1-stage heat and 1-stage cool
Power options: 24-volt system power or two AA alkaline batteries
Display: Backlit digital display with Fahrenheit or Celsius selection
Terminals: C, RH, Y, W, G, RC, and O/B
System applications: Compatible 1-heat, 1-cool systems, including selected heat pump configurations without auxiliary heat
Fan control: On and Auto settings
Additional indication: Low-battery and service-filter reminders

Detailed Description

The S1-THEC11P5S measures the room temperature and compares it with the selected temperature. When the room requires heating or cooling, the thermostat energizes the appropriate HVAC outputs. The single-stage design is intended for equipment with one heating demand and one cooling demand.

The front display shows operating information and provides backlighting for easier viewing in low-light conditions. The mode switch selects HEAT, OFF, or COOL. The fan switch selects continuous fan operation with ON or automatic fan operation with AUTO.

The thermostat uses a front-access battery compartment. Two AA alkaline batteries should remain installed even when 24-volt power is connected. In a system-powered installation, the batteries help preserve the clock during a power interruption.

The backplate includes a thermal insulating sheet with wire slots. Leave this sheet in place because openings in the wall can allow drafts to reach the thermostat and affect room-temperature readings.

Safety

Disconnect power to the heating and air-conditioning equipment at the main fuse panel or circuit breaker before removing the old thermostat or wiring the new one.
Confirm that the existing heater and air conditioner operate correctly before beginning installation.
Use a qualified technician if any wiring, system type, or installation step is unclear.
Replace both AA alkaline batteries at least every 12 months. Replace them immediately when the low-battery symbol appears.
Annual battery replacement is especially important where freezing temperatures could occur. Exhausted batteries may prevent the heating system from turning on.
The thermostat complies with applicable FCC Part 15 operating conditions. It must not cause harmful interference and must accept received interference, including interference that could affect operation.

Setup and Installation

Required Tools

Flat-blade screwdriver
Wire cutter and stripper

Remove the Existing Thermostat

Switch off power to the heating and cooling equipment at the main electrical panel.
Remove the old thermostat cover. Check for retaining screws if the cover does not release easily.
Loosen the screws securing the old thermostat base or subbase to the wall, then lift it away.
Disconnect the wires one at a time. Label each wire with the letter of the terminal from which it was removed.
Keep the old thermostat available until the new installation has been tested successfully.

Connect the Wires

Use the terminal function rather than wire color when transferring conductors. The following mapping applies to the compatible systems described for this model:

C: Common conductor
Y: Cooling equipment
W: Heating equipment
G: Fan control
O/B: Heat pump reversing valve
RC: Cooling transformer power
RH: Heating transformer power

The factory jumper between RC and RH is used for systems with one transformer. Remove this jumper only when connecting a dual-transformer system with separate heating and cooling power supplies. For dual-transformer wiring, the common conductor must be connected to the furnace common terminal.

Typical wiring uses 18- to 22-gauge unshielded cable. Depending on the equipment, the installation may use two, three, four, or five conductors. A common wire is optional in the listed configurations; when one is not used, the thermostat must be powered by two AA alkaline batteries.

Jumper Configuration

Set the internal jumpers before attaching the thermostat to the backplate. The correct settings depend on the equipment type:

Gas heat with electric cooling: Set J1 to GAS and J2 to ELEC/GAS. J3 is not used.
Electric heat with electric cooling: Set J1 to ELEC/HP and J2 to ELEC/GAS. J3 is not used.
Heat pump with an O reversing valve: Set J1 to ELEC/HP, J2 to HP, and J3 to O.
Heat pump with a B reversing valve: Set J1 to ELEC/HP, J2 to HP, and J3 to B.

The thermostat does not provide auxiliary or emergency heat control for heat pump systems. Do not connect unused O/B output wiring to equipment.

Install the Batteries

Press down on the battery cover on the front of the thermostat.
Pull the cover outward to open the battery compartment.
Remove the old batteries and install two new AA alkaline batteries with the polarity matching the markings inside the compartment.
Insert the bottom hook of the cover into its slot and press the cover closed until it snaps into place.

If the thermostat is connected to 24-volt power, keep the batteries installed so the clock can continue operating during a line-power interruption.

Complete the Installation

Route the conductors through the slots in the thermal insulating sheet without removing the sheet.
Secure the backplate to the wall. Avoid overtightening the screws, especially on an uneven wall.
Attach the thermostat to the mounted backplate.
Restore power to the HVAC system.
Set the mode, fan operation, temperature scale, clock, and programmed schedule as required for the installation.

Test Operation

Move the fan switch to ON while the mode switch is set to OFF. The indoor fan should run continuously.
Move the mode switch to HEAT.
Raise the temperature setting to approximately 10 degrees above the current room temperature. The heating equipment should start.
Move the mode switch to COOL.
Lower the temperature setting to approximately 10 degrees below the current room temperature. The cooling equipment should start.

The compressor protection feature may delay heating or cooling operation for up to five minutes. This delay is normal; do not repeatedly switch modes while waiting for the equipment to respond.

Battery Replacement and Maintenance

Replace the batteries at least once a year, or sooner when the low-battery indicator appears. Battery replacement is necessary even when the thermostat normally receives 24-volt system power, because the batteries support clock operation during a power interruption.

Keep the display and thermostat controls free of dust, and avoid allowing moisture to enter the housing. The installation instructions specifically identify filter cleaning or replacement as routine HVAC maintenance; follow the equipment manufacturer’s maintenance schedule for the correct filter procedure.

Troubleshooting

Slide Switches Are Difficult to Move

The backplate may be fastened too tightly against an uneven wall. Loosen the mounting screws slightly and check whether the switches move more freely.

Cooling Does Not Start

Lower the cooling setpoint below the current room temperature.
Confirm that the mode switch is set to COOL.
Replace weak or depleted batteries.
Allow up to five minutes for the compressor protection delay to expire.

Heating Does Not Start

Raise the heating setpoint above the current room temperature.
Confirm that the mode switch is set to HEAT.
Replace weak or depleted batteries.
Check that the equipment power has been restored after installation.

Fan Does Not Run

Move the fan switch firmly into either the ON or AUTO position. In automatic operation, the fan normally runs only when the HVAC system calls for the corresponding heating or cooling operation.

Incorrect Temperature Reading

Check that the thermal insulating sheet remains installed over the wall opening and that wires are routed through its slots. Drafts entering from inside the wall can influence the thermostat’s temperature measurement.

Warranty

The S1-THEC11P5S includes a one-year limited warranty against defects in materials and workmanship, beginning from the date of original installation. The stated coverage applies to the product at its original installation location and may provide a new or remanufactured replacement part at the manufacturer’s option.

The warranty does not cover labor or other costs associated with diagnosis, removal, installation, shipping, servicing, or handling. It also excludes routine maintenance, incorrect installation, misuse, unauthorized modification, unsuitable parts, electrical-service problems, weather or accident damage, and indirect or consequential property or commercial losses where permitted by law.

Pros & Cons

Pros: Backlit display, 5+2-day programming, Fahrenheit or Celsius selection, battery or 24-volt operation, service-filter indication, and support for several common single-stage HVAC configurations.
Pros: Separate RC and RH terminals allow the factory jumper to be adapted for single- or dual-transformer systems.
Cons: The thermostat is limited to one heating stage and one cooling stage.
Cons: Heat pump installations are limited to systems without auxiliary or emergency heat control.
Cons: Batteries require regular replacement to maintain dependable operation, particularly in areas exposed to freezing temperatures.

PDF

Faqs

How do I safely install the S1-THEC11P5S programmable thermostat?

Turn off power to the heating and air-conditioning equipment at the main fuse panel or circuit breaker before removing the old thermostat. Photograph or label each wire with its original terminal marking, then compare those markings with the new thermostat connections. Use the supplied wall plate and keep the insulating label over the wall opening to prevent drafts from affecting temperature readings. If the wiring or system type is unclear, stop and have a qualified technician complete the installation.

Which HVAC systems are compatible with the S1-THEC11P5S?

The S1-THEC11P5S is designed for many one-stage heating and one-stage cooling systems. The installation instructions show applications for gas or electric heat, electric cooling, two-transformer systems, two-wire gas heat, and heat pumps using either an O or B reversing valve. Heat-pump installations shown do not include auxiliary or emergency heat control. Confirm that your equipment matches the wiring diagrams and jumper settings before connecting power.

How should the wires be connected to the S1-THEC11P5S terminals?

Match the old thermostat terminal functions rather than relying only on wire colors. Typical connections are C for common, Y for cooling, W for heating, G for fan, R or RC for power, and O/B for a heat-pump reversing valve. The factory jumper between RC and RH is used for a single-transformer system. Remove it only when wiring separate heating and cooling transformers, and connect each power wire to the appropriate terminal.

How do I replace the batteries in the S1-THEC11P5S thermostat?

Open the front battery compartment by pressing down on the cover and pulling it outward. Remove both old batteries and install two new AA alkaline batteries in the correct orientation, then place the lower cover hook into its slot and snap the cover closed. Replace the batteries at least every 12 months and immediately when the low-battery symbol appears. Even with 24-volt system power, keep batteries installed so the clock can continue during a power interruption.

What should I do if the thermostat does not turn on the heating system?

First confirm that the mode switch is set to Heat and raise the heating setpoint above the displayed room temperature. If the display shows a low-battery condition, replace both AA alkaline batteries immediately. Check that power has been restored to the HVAC equipment and that the circuit breaker is not open. A heat-pump or compressor-related delay may affect operation, so allow several minutes before deciding that the system has failed to respond.

Why is the air conditioner not starting with the S1-THEC11P5S?

Set the mode switch to Cool and lower the cooling setpoint below the current room temperature. Make sure the batteries are not weak and that the HVAC equipment has power at its breaker or disconnect. The thermostat may intentionally delay cooling for up to five minutes because of its compressor lockout feature. If cooling still does not start after the delay, return the setpoint to a normal value and verify that the wiring matches the equipment terminals.

Why does the fan not run when the compressor is operating?

Check the fan switch and move it firmly into either Auto or On. In Auto, the thermostat operates the fan when the system calls for heating or cooling; in On, the fan should run continuously. A switch that is positioned between settings may prevent the expected fan operation. If the slide switches feel unusually stiff, the wall plate may be fastened too tightly against an uneven wall. Loosen the mounting screws slightly and test the switch again.

How can I test heating, cooling, and fan operation after installation?

Restore power to the HVAC equipment, then set the thermostat to Off and move the fan switch to On to verify continuous fan operation. For heat, select Heat and set the target temperature about 10 degrees above room temperature. For cooling, select Cool and set it about 10 degrees below room temperature. Allow up to five minutes for compressor protection delays. Return the controls to the desired mode and fan setting after testing is complete.