Help! I am switching from a Honeywell Chron II to a new Total Line P374-2800 and can not get the P374 to light up. Red wire volts read 24vac at wall so am getting proper voltage at stat. HWC II had jumper between R and Rc. Do I need similar jumper on P374? If so, where?
Have Carrier 2ton a/c split system with 1995 80% Carrier gas furnace

Here are P374 terms as marked on base plate and schematic.

(G-fan) (Y1-cool) (W1/O/B-Heat 1st stage) (R-pwr) (C-common) (W1/O/B- Rev. valve) (W2 Heat stage 2) (Misc 1) Misc 2) Misc 3) (RS+5 remote sensor +5vdc) (RS1- remote sensor signal) (RSGND remote sensor ground) (RS2-remote sensor signal 2) (CK1 dry contact switch 1) (CKGRN-dry contact switch 2)

This thermostat requires a common wire connected to the "C" terminal where as the old one may not have needed a common wire, no jumper on this thermostat, good luck, Mike

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Originally Posted by Scrambler81st

Help!! I am switching from a Honeywell Chron II to a new Total Line P374-2800 and can not get the P374 to light up. Red wire volts read 24vac at wall so am getting proper voltage at stat. HWC II had jumper between R and Rc. Do I need similar jumper on P374? If so, where?
Have Carrier 2ton a/c split system with 1995 80% Carrier gas furnace

Here are P374 terms as marked on base plate and schematic.

(G-fan) (Y1-cool) (W1/O/B-Heat 1st stage) (R-pwr) (C-common) (W1/O/B- Rev. valve) (W2 Heat stage 2) (Misc 1) Misc 2) Misc 3) (RS+5 remote sensor +5vdc) (RS1- remote sensor signal) (RSGND remote sensor ground) (RS2-remote sensor signal 2) (CK1 dry contact switch 1) (CKGRN-dry contact switch 2)

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Thanks, Mike. For clarification purposes, you are saying that I need to have a wire run from "C" on the air handler (furnace) computer board to "C" terminal on P374?. and DO NOT even attempt to use a jumper on P374?

Yes that is correct. Mike

Hi my name is kim,
My question is if I can install Totaline P/N P274-2800 T-Start to the Tempstar gas package unit?