[emanuel9681]

I recently purchased a Ace brand programmable thermostat and some of the letters aren't on the new thermostat that are on the old one. Could any one help me!!

Old: R = R
G= G
O= O
Y = Y
W2= B
E= PURPLE WIRE
L = WHITE WIRE


New= A
RH (jumper to RC)
W2
RC
G
Y
W1
O
B
C

[hvac1000]

C Black 24 Vac Common From one side of the 24Vac transformer (Think of this as 24Vac neutral
R or V Red 24 Vac Power to be switched From other side of the 24Vac transformer (Think of this as 24Vac L1)
Rh or 4 Red 24 Vac Heat call switch power Same as R, but dedicated to the Heat call switch
Rc Red 24 Vac Cooling call switch power Same as R, but dedicated to the cooling call switch
G Green Fan Fan switch on thermostat - is connected to R when Fan /Auto switch is in the fan position
W White Heating call Is connected to R or Rh when themostat calls for heat. (Might be jumpered to Y on a heat pump. On others might be second stage heating
[B]Y Yellow Cooling call Is connected to R or Rc when themostat calls for cooling. Also Cooling or 1st stage heating on a heat pump
Most often connected to G when Fan switch is set to auto
New signals - for heat pumps and staged systems[/B

Y2 Blue or Orange 2nd stage Cooling
W2 Varies Second Stage Heating First stage Auxiliary heating on a heat Pump
E Varies,
blue, pink,
gray, tan Emergency heat relay on a heat pump. Active all the time when selected, usually not used. Disable the heat pump and turn on first stage Aux heating
O Varies,
Orange Reversing valve Energize to cool (Changes from heat to cool on heat pumps)
B Varies,
blue, black
brown, orange Sometimes common side of transformer. Needed on some electronic thermostats or if you have indicator lamps
OR
Reversing valve (energize to heat) above. York and Trane sometimes use (B) as common. Might be heating changeover or on older stuff common of transformer.
X Varies SEE NOTES BELOW Might be common but sometimes emergency heat relay
X2 Varies Second stage heating or indicator lights on some thermostats Might be emergency heat relay
T Varies,
Tan or Gray Outdoor anticipator reset Used on GE/Trane/American Standard and some Carrier Products.
L Varies Service Light

Without model numbers this is as good as it is going to get.