To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.
The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Need to contact us? Visit

How many strand t-stat wire?

Gee134Gee134 Member Posts: 1
I just had my old oil fired hot air furnace replaced with a new oil furnace with an ECM variable speed fan (if that matters). I currently have a 2 strand t-stat wire. He's also coming back to install a heat pump and humidifier. The home has never had a heat pump/central air system or humidifier prior. I'm a low voltage electrician and would prefer running the wire myself. My 2 questions are...How many strand t-stat wire would I need for a duel fuel central air system with a humidifier? (oil warm air furnace with humidifier, heat pump, & ac) He said "probably" 7, but I didn't feel confident of his answer. Second, How would I run the cable for him? Currently my wire runs directly from furnace to t-stat. Would I run 1 t-stat to furnace, 1 from furnace to humidifier on return, and 1 furnace to heat pump? Or 1 continuous run? Thank you for the help. A licensed contractor is doing the installation of the equipment and termination of the wires. I just want to have it in place for him for both cost and time savings.


  • billtwocasebilltwocase Member Posts: 2,385
    I like

    6 cord thermostat wire. Is there going to be a humidistat up in the house? A/C ?
  • DClarkDClark Member Posts: 1

    Depending on the t-stat and HP, up to 12. I usually get away with 8

    R 24v

    C 24v com


    W1 1st stage htg

    W2 2nd stage htg

    Y1 1st stage cooling

    Y2 2nd stage cooling

    G fan

    O/B reversing valve

    S(2 or 3) outdoor sensor
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!