How many strand t-stat wire?

Gee134

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.

billtwocase

I like

6 cord thermostat wire. Is there going to be a humidistat up in the house? A/C ?

DClark

Conductors

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

R 24v

C 24v com

AUX/EM

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