Source 1 S1-THEC11NS Thermostat

Source 1 S1-THEC11NS Thermostat

  • $56.05

Source 1 S1-THEC11NS Non-Programmable Thermostat

The S1-THEC11NS offers basic operation of HVAC equipment at an affordable price. Operating on either 24V system power or 2 AA batteries (included), the S1-THEC11NS is compatible with most equipment including millivolt systems. The front loading compartment makes battery replacements a snap.

The separate RC and RH terminals allows easy retrofit on older systems with dual transformers.

  • 1-Stage Heat / 1-Stage Cool thermostat
  • Works with Heat Pumps, Gas Electrics or Hydronic Heating
  • 2, 3, 4 or 5 wires compatible
  • Setpoints are never lost in power failure
  • Fully electronic for accurate, responsive temperature control
  • Separate RC and RH terminals
  • Battery operated
  • Compatible with 24VAC, DC, and millivolt systems
  • Battery or system powered
  • *Does not control auxiliary heat
  • Large LCD
  • Room temperature & set temperature displayed
  • Easy to operate
  • Heat/Off/Cool – Fan On/Fan Auto
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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.

  • 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.


  • 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.

  • 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.

  • 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.

  • 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

  • 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.

  • 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.


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

    No, not with this non-programmable model.