Heat Pump Thermostat Wiring.

Discussion in 'HVAC Heating & Cooling' started by Randyj, Jul 10, 2008.

  1. Randyj

    Randyj Master Plumber

    Messages:
    1,047
    Location:
    Alabama
    Actually I have two questions but will post the other separately. I do a huge amount of repair and maintenance work. Every time I get involved in HVAC sytems and have to wire up a thermostat I get lost. The system I"m currently working on is a new Rheem heat pump. Wires coming from the package unit are pretty standard... red, yellow, green, blue, brown, white(with black stripe). There are 8 terminals in the thermostat (White-Rogers 1F89-211). In general I'm following color codes but am confused as to where the blue and brown wires go although I know the brown is the common for the transformer. The terminals in the thermostat are marked O/B Y G W2 E C L R ... so... which wire goes where????
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    You have to wire by function. One thing to watch out for...Rheem units have the reversing valve energized on HEAT where many other brands have the reversing valve energized on COOL. This will result in differences involving the B and O wires, usually. You need to take the manual for your T-stat and match the wiring to the diagram for the Rheem unit.
  3. Randyj

    Randyj Master Plumber

    Messages:
    1,047
    Location:
    Alabama
    It took mostly studying and deduction to figure it out. Plus I found a site by doing a google search that explained thermostat control wiring pretty decently. The brown wire on this unit is for common from the transformer which was attached to the "c" terminal of the thermostat and the blue wire is for the heat energizer(reversing valve) which is connected to the O/B terminal...all others were simply color coded.... I've wired up several thermostats and have not done it frequently enough to remember the function of each wire. I'm still learning. Before switching the unit on I had a HVAC pro to check everything out. Only thing I had not done was to put the o/b switch in the correct position...he flipped the switch and that's all. It worked perfectly. Nothing in the product manual/information tells which position the switch is supposed to be in...at least, not in layman's terms.
Similar Threads: Heat Pump
Forum Title Date
HVAC Heating & Cooling Ductless heat pump question Sunday at 2:43 PM
HVAC Heating & Cooling Package heat pump vs gas pack -costs vs each other to buy Nov 2, 2014
HVAC Heating & Cooling Help! Exchanger on Pool Heat Pump Leaking! Mar 8, 2014
HVAC Heating & Cooling Electrical question fir 5 ton pool heater heat pump Feb 28, 2014
HVAC Heating & Cooling heat pump problem Feb 8, 2014

Share This Page