Thermostat Question - 5-wire system, 6-wire thermostat

[aphex]

My friend is replacing a 5-wire thermostat with a 6-wire programmable thermostat...

Pic

Here is the picture of the 6 wire thermostat I?m trying to rewire to a 5 wire system.
Basically, I need to figure out how the Rc/Rh on the new system match up to the R/O wires of the old system.

 

[VirginiaDonkey]

make sure you bought the right type programmable thermostat. some are for heat pump only, some are for gas heat, heat pump air

 

[xrax]

I went from a 6 wire to a 5 wire thermostat. The 6 wire had W-O-G-R-C-Y labels. The 5 wire has G-Rc-Rh-Y/O-W/B-Y1. Y1 is for a heat pump. G went to G. Y/O went to Y. O wasn't hooked up. R went to both Rc-Rh (jumper). W went to W/B. The C meant power, but it can also mean compressor by my directions.

Generally G means fan. R means heat and cool relay. Rc means cool relay, Rh heat relay. Y/O means A/C compressor. W/B means heat. Without seeing the original thermostat and the instructions for the new it is hard to determine.

 

[Rubycon]

O is usually the reversing valve solenoid on those pesky heat pumps.

Oh and the R line is the hot side of 24v - touch this to G and your blower will run, for example.

As always, RTFM.

And KISS works too. (T87F forever!)