Replacing an old Lennox thermostat for electric forced air heat, a/c, heat pump with wire attached to: V,R,F,M,A,Y,X. I bought a Ritetemp 6010.

How old exactly is that furnace?

Here is a old LUX cross over sheet. It will work for the Ritetemp. Always double check your low voltage wiring.

http://www.luxproproducts.com/crossref/htPmpCrsRefWith.pdf