This site appears helpful, but I didn't see my situation, and I tried the Honeywell wiring wizard but it doesn't include my model.
I currently have a White Rodgers (9510E7) rectangular thermostat and I am trying to replace with Honeywell 5-2 Day Programmable RTH230B.

Currently there are 8 wires coming out of the wall
Blue- not connected to anything
Black- not connected to anything
Red- R
Brown- C
Yellow- Y
White- W2
Green-G
Pink- O

The new thermostat only has room for 5 wires. Some are straight forward, but others are confusing. The outlets are:
Rh- Heating Power
Rc- Cooling Power
W- Heating Signal
Y- Cooling Signal
G- Fan
*Jumper wire between Rh and Rc.

Can someone please tell me what wires connect to the Rh,Rc,W,Y,G Honeywell outlets and which are not used (and possibly why not used). Thanks in advance!

During a recent electrical outage (extended time over 12 hours), the automatic pilot light on the furnace went out. It is a Carrier model and has an electronic igniton, I cannot get the pilot light to relight. Is there a trick, or do I need a service call?

Johhny... I just had asked for this thread to be moved to heating/cooling section. I'm out since cooling appears to be involved.

Joankev... Try this... shut off power switch to the furnace, then reset the breaker at the breaker box or install a new fuse at the fuse box to assure yourself that power is coming out of electric panel, then turn the power switch at boiler back on. It will take a minute or so for pilot to ignite.

If that doesn't work then unless you are very handy with an electrical tester you should probably call in a qualified service technician... an HVAC contractor!

Let us know how you make out!

MARK

Johnny, hopefully this will help.Thermostat wiring colors and furnace terminal designations repair.