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Source 1 S1-THEC11NS Thermostat

Source 1 S1-THEC11NS Thermostat

York

The York S1-THEC11NS is a commercial-grade, non-programmable digital thermostat designed for 1 heat / 1 cool configurations in residential and light commercial applications. This low-voltage control is engineered for compatibility with conventional single-stage gas or electric furnaces, air conditioners, and millivolt heating systems. As a veteran-preferred HVAC replacement part, it offers a reliable digital upgrade for older mechanical mercury-bulb thermostats, ensuring more precise temperature regulation without the complexity of scheduling. The unit features dual power options, functioning via 24VAC hardwiring or 2 AA alkaline batteries, providing flexibility for 4-wire or 5-wire installations. Its intuitive interface includes a clear LCD screen, dedicated "COOLER" and "WARMER" buttons, and a front-loading battery door for rapid field servicing. The S1-THEC11NS wiring is straightforward, utilizing standard terminal designations (R, C, W, Y, G) with factory-installed jumpers for single or dual transformer systems, making it a robust solution for maintaining stable environmental control in diverse HVAC environments.

Key Benefits
  • Universal System Compatibility: Operates seamlessly with 1H/1C conventional gas, electric, and oil systems, as well as millivolt applications and single-stage heat pumps without auxiliary heat.
  • Flexible Powering Options: Can be powered by 24V low-voltage wiring for a permanent connection or by two AA batteries for systems without a common (C) wire.
  • User-Friendly Interface: Features a large, backlit digital display for easy reading in low-light utility rooms or dark hallways.
  • Maintenance-Focused Design: Includes a front-access battery compartment and a low-battery indicator to prevent system downtime during extreme weather.
  • Precise Temperature Control: Replaces inaccurate mechanical levers with a digital thermistor for tighter temperature swings and improved equipment efficiency.
Common Questions

Is the York S1-THEC11NS compatible with my 2-wire heating system?
Yes, this unit is an excellent choice for 2-wire, heat-only systems, including gas-fired wall heaters and millivolt floor furnaces, when operated on battery power.

Does this thermostat require a common wire (C-wire) for installation?
A common wire is recommended for constant power, but it is not required. You can utilize 2 AA alkaline batteries to power the logic circuit if a C-wire is not present at the mounting location.

Can I use this thermostat for a heat pump with emergency heat?
No, the S1-THEC11NS thermostat is specifically designed for 1-stage heating and cooling. For systems requiring auxiliary or emergency heat (multi-stage), a 2H/1C or 2H/2C model is required.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.

QUESTIONS & ANSWERS

Ask a Question

  • the word heat is flashing, what could that mean?

    It should mean the unit is calling for heat. Please see manual for details.

  • how do you know id batteries need changed?

    A low battery icon will be displayed on the screen.

  • How do you open this thermostat to see about the batteries

    Hi, just flip open the front cover and you will see the battery cover. Thanks.

  • what if the lights are flashing on and off.

    Could be a power source problem but please refer to manual link below for troubleshooting.

    Owner's Manual

  • Have a source 1 thermostat. How do I set it

    Please see instruction manual here.

  • How do you set thermostat, mine doesn't have a manual

    Please see link below for manual.

    Manual

  • Typical lifespan

    It depends. One customer's unit is dead within a year while some are still going strong after 10+ years. These can be damaged by the system power / load so it may not be the thermostat's problem.

  • When I turn it on to heat, I can hear a 'click' as it presumably sends the current temp to the heater. Sometimes it does not click, and the heater will not even try to turn on.

    Please see page 23 for the troubleshooting section at link below. Thank you.

    Manual

  • My heater is not coming on

    Please see link below to troubleshoot the thermostat. If that doesn't help you may need to call a contractor to check your system.

    https://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf

  • THE HEAT WON'T GO ON, I PUSH THE BUTTON TO RAISE HEAT BUT NOTHING HAPPENS, IF I TURN IT TO COOL IT WILL WORK THERE.

    If the heat is blinking then it is calling for heat already. In that case you may have other problems with the heating unit if the unit is not turning on.

  • I don't see how to change the time (fall back)- this was set up for us by the service man and i have not booklet or instructions

    THEC11NS is not a programmable thermostat so it does not have any time settings.

  • My thermostat seems to be stuck on 69 for heating, despite trying to set it higher. Flashing Heat.

    If it is flashing heat then it is calling for heat but your unit is not heating up. You may have something wrong with the heating unit.

  • How do I get my heater to go on

    Turn it to heat and auto then set the temperature. Thanks.

  • How to make the room cooler?

    The thermostat controls on and off of your ac unit based on the temperature setting. The AC still has to be able to cool it down so if the thermostat is calling for AC but your AC is not cooling then you will need to check your AC.

  • What does it mean when cool is flashing and the temperature continue to increase higher not lower?

    That means the thermostat is already calling for cool but your A/C system is not cooling down the area. Something is wrong with the A/C system.

  • Is it automatically?

    Yes it controls on and off of your AC automatically depending on your temperature setting. Thank you.

  • How to get fan off

    Please see manual below.

    http://source1thermostats.com/documents/S1-THEC11NS/Manual%20Source1%20S1-THEC11NS%20Rev%204.pdf

  • How do you open battery compartment?

    Here is the info: http://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf

  • Display is reading 45. Does the thermostat need to be replaced? System seems to still be running. We are using air conditioning.

    If the temperature is way higher than 45 and it senses 45 then something is wrong with the thermostat.

  • how do I get an owners manual? I recently purchased the home but the manual was not included.

    Please see manual at the link below. Thanks.

    http://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf

  • Why doesn't it turn on

    Please see owner's manual below to troubleshoot unit.

    http://source1thermostats.com/documents/S1-THEC11NS/Manual%20Source1%20S1-THEC11NS%20Rev%204.pdf

  • Source 1 S1-THEC11NS Thermostat First of all, thank you very much for your help! The problem: Having changed the new batteries and switched to mode “HEAT”, the display was flashing first repeatedly “HEAT 32” or “HEAT 35” by set temp of 45 for more than 5 minutes, and then it remained blank with the only two strokes (- -) on the display forever; nothing happened, neither fan nor heat! My Questions: 1. What are the causes of this problem? 2. How can I fix it by do-it-myself? With a new Source 1 S1-THEC11NS Thermostat? 3. If it was a big issue and a professional were needed, what could be the cost? Thank you again so much for your answers!

    Please see link below for troubleshooting info(P.23).

    http://www.thermostatsusa.com/pdfs/S1-THEC11NS-manual-rev4.pdf

    We don't know what might be wrong without checking it out in the field. You might be able to troubleshoot it if you have a voltmeter and know how to do it. You can call a pro to check for you, hourly rate varies but you can always call around to see if anyone can give you a free estimate. Thank you.

  • If display is blank after changing the batteries, does thermostat dead need replacement?

    Yes, if the batteries are good and there is still no display there might be some problem with the thermostat.

  • Unit doesn’t shut down when thermostat reaches set temperature

    It could be contactor problem, wiring problem, short circuit problem, thermostat problem etc. Need to pinpoint what the problem is on site.

  • I'm looking for this do you have it source thermostat model s1-THE 11P5S

    S1-THE 11P5S is not coming up as a valid part number. Please check again. Thanks.

  • The display is blank. what doe this mean? I changed the batteries and its still blank

    This thermostat can be system powered or battery powered. If yours is wired for battery powered and the display is blank then either the battery itself does not have enough juice or the display is dead. Thank you.

  • How do i set temperature

    Just use the up and down arrow to set temperature. Please see link below for more information. Thank you. Owner's Manual

  • How to put it on auto

    Here is the user manual:

    https://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf


  • Why my thermostat flashes “set timer”?

    Please see the user manual:

    https://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf


  • how do I flip it open

    Here is the user manual:


    https://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf


  • How do you set the heat tempature

    Here is the manual:


    https://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf

  • Why does the heater not come on occasionally

    It could be the thermostat, controls within the heater, loose wire etc. It needs to be check in the field.

  • What if thermostat has nothing on screen and air conditioner just keeps running constant?

    Please check with your local licensed contractor.

  • How to open the thermostat to see the battery

    https://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf

  • Has blinking numbers it goes up and down between numbers

    https://source1thermostats.com/downloads/ManualSource1S1-THEC11NSRev4.pdf

  • My office thermostat is set at 67 degrees I don’t see a reset button. It’s freezing in our office how do we get the heat working

    There is no reset button but you can turn it off, wait a few mintues then turn it back on. Please see link below to troubleshoot the thermostat. If the thermostat is calling for heat already it could be your heating unit that is not working properly.

    Manual

  • Does this model have a back lit display?

    No it does not.

  • Can I program the system to turn on and off at certain days and times?

    No, not with this non-programmable model.