How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask BillyHvac Your Own Question
BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22515
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
12672042
Type Your HVAC Question Here...
BillyHvac is online now
A new question is answered every 9 seconds

what are the s-1,s-2 terminals on a thermostat use for

Customer Question

what are the s-1,s-2 terminals on a thermostat use for?
Submitted: 7 years ago.
Category: HVAC
Expert:  BillyHvac replied 7 years ago.
Chat Conversation Started
Billy :

I do not know what thermostat you have...but s1 and 2 are normally for remote sensor. Thermostat in one spot but the temperature controlled in another. Very popular in commercial settings where the thermostat is in a office and the sensor in the retail space.

Customer:

this is in a residential setting. On a heat pump. The t'stat is programmable etc. The AHU does not this wiring on the board.

Billy :

Ok, then that one is for outdoor sensor. If you wanted you could hook up an outdoor sensor and have a set point for heat pump changover if you had a gas back up furnace...

Customer:

no gas back up. heat strips and the heat pump only has 5 wir connections. r/w/y/o/c

Billy :

Great...then you will just disregard the unapplicable wire terminals.

Customer:

did that and the ahu terminal board faults. The led indicator (DAYTON 1.5T AHU) tells me thatthere are to many open relays?

Billy :

What is model number of air handler

Related HVAC Questions