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Wiring a thermostat.

Ruud heater model (-)HQA(-) five wires coming out of the unit. Two black labels G and W. One yellow wire coming from the 24v transformer. And one purple and one brown. Need to know how to wire just the heater without the air unit.

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Re: Wiring a thermostat.

The green one is for the evaporator fan motor relay. The white one is for the heat sequencer. The one coming out of the transformer is usually red BUT it will be the power so attach it to the terminal labeled R on the thermostat. If there is a RH and a RC, put a jumper in between them. See if the purple and brown ones go to the fan motor, if so, then just cap them off with wire nuts, and that should have your heat working. Check to make sure the green and white wires go to their designated areas (the heat sequencer looks like a stacked set of thermal overload switches and the relay looks like, well, a relay) and neither ground out before flipping on power or you will pop your transformer.

Posted on Jan 28, 2008

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No cold air

sounds like you need a new contactor but check to make sure you have 24v at the control wiring side of the contactor first. If you don't have 24v check the condenser low voltage wiring and the thermostat wiring.

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Need to know full low voltage wiring information to thermostat

Usually the Red wire provides 24v and connects to the R termenal-
Next the Green wire is to the indoor blower motor and connects to G terminal-
Next the Yellow wire is to the outdoor unit to call for cooling and will engage power to the contactor solenoid to pass 240v power to compressor and power to Start/Run capacitor and fan! It will connect to the Y terminal-
Next is the White wire an it calls for Hea and is connected to the W terminal-
If you have an Orange wire it is for the reversing valve of a heat pump system.
Remember the red feeds 24v to each of these colored wires to complete a connection and pass power to the device being called into action.
BLue or Black wire will be ground if the thermostat needs power instead of batteries.

Red wire is the only hot 24v wire going to the thermostat period! And it comes from the Transformer!

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1 Answer

I need wiring manual for goodman mini split.

outside unit L1 and L2 are load (input 240vac)
then you have control voltage, usually yellow and blue (24vac) this connects to some 18/2 thermostat wire which goes inside as white and red.

note: this unit may only need 24v control which is 2 wires from the inside unit and also 3 wires 2 hot 1 ground for line voltage.

on the inside unit you have green, white, blue and red control wires.

on your thermostat you have white, red, yellow and green

you run the wire from the outside unit to the inside unit. then run a 18/4 wire to the thermostat if wired and join the following wires.

inside unit thermostat outside unit

Oct 08, 2009 | Air Conditioners

1 Answer

Will a short/ground in the thermostat wires cause a model(-) HQA to burn up the 24 volt transformer

If the transformer wires are shorted together, this will burn up the transformer. Normally transformers on the LV side (24 volt) are not grounded, but the solenoids that they control could be grounded, and a t-stat wire that is unintentionally grounded could burn up the transformer, but its not likely.

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24v wiring for RHEEM heat pump

Brown wire connect to com C on terminal block in your furnance (0VAC from 24VAC transformer)
Yellow turn on compresor (hot wire from 24VAC Transfrormer)
Blue switch Valve from AC to Heat (hot wire from 24VAC Transfrormer)
Purple prevent starting compressor in Heat pump and furnace in same time

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1 Answer

Thermostat wiring

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Please note. Not all installers use the proper color codes when they install or replace equipment. It may be necessary go go to the furnace or outdoor unit to verify what wires are for what purpose. Also be sure there are no splices in the wire that could change the wire colors between components.
  • R (red) or Rh (Red heat) 24 volts from equipment.
  • Rc (Red cooling) 24 volts from transformer in cooling equipment.
Note: If only furnace has a transformer and cooling equipment does not jumper Rc and Rh.
  • W (White) sends 24 volts to furnace control to start the heating cycle.
  • W2 (no standardized wire color, usually whatever wire color is available) controls second stage heat.
Note: W2 is most often used for heat pumps to control what is called emegency heat or Auxillary heat, and most often will use the white wire.
  • Y (yellow) often (blue) is used, controls cooling unit (outdoor condensing unit) also is used for heat pump heat.
  • Y2 (no standardized wire color, usually whatever wire color is available) controls second stage cooling.
  • G (Green) controls the fan "on" operation of the furnace/air handler. Also often is used to start the blower for many electric furnaces.
  • C (common) most often brown but can also be black or other color available to installer.
  • O (orange) Energizes heat pump reversing valve for cooling (Trane and most other brands).
  • B (Blue) Energizes heat pump reversing valve for heating (Rheem, Ruud and Weatherking).

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1 Answer

Ho to turn on central AC unit? (Ruud High Efficiency)

This is typical wiring for a 4 wire thermostat

R = Red One Side of 24 volt Transformer
G = Green Blower relay
Y = Yellow Cool Condensing unit
W = White Heat Furnace

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1 Answer

I have a carrier air/heating unit with pump. It has 8 wires. Brown,blue, white, yellow, green, black, orange,and red. I'm trying to install honeywell thermostat. The wires from my unit are suppose to go...

Turn the power off to the air handler. Open the control cover. Write down what color wires go together at the wiring terminal. All 8 wires are probably not used.
Post the findings here.
In most cases,
E= brown-emergency heat
AUX=white-auxillary heat to supplement HP
Y= yellow-to compressor for heat or cool(hp)
G=green-indoor fan
O-orange-reversing valve on HP when energized in COOL
L=t-stat light(probably not used)
R=red-24v incoming power
B=black-reversing valve on HP when energized in HEAT
C=blue-common wire for 24v
Only one of the "O" or "B" will be used. Not both.

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1 Answer

Manual Thermostat replcaement with Programmable Digital unit.

Hopefully there are markings on the old t-stat as to what terminal is what.
on the honeywell 8000 use the heat pump labeling and then the standard wiring would be
R- red
Y- yellow
B- O/B
C- black
G- green
There should not be a bare wire, it probably just has the insulation stripped back way too far.
You should probably open the furnace and compare the terminal label in the furnace to the wire color. normally yellow and blue pass through the furnace and are wire nutted to wires going to the outdoor unit. In the furnace the white wire will connect to the w or w1 terminal. also, you will need to set the Honeywell stat to have the following parameters.
other parameters that I did not specify, you may read the manual and make your own decision but I recommend factory settings for the other parameters

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5 Answers

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we are trying to install a goodman heat pump with a rheem air handler, the orange wire is hook up and the unit is still staying in the heat mood. does anyone have a wiring diagram for the air handler, their is some white wires in the air handler one with a purple strip and one with a black strip we need help

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