I just bought a honeywell rth7000 thermostat, i am installing in a old house that only uses 2 wires, one is green and the other brown, can anyone advise me how to connect these 2 wires to this unit i am not sure exactly where to connect them to on the honeywell thermostat--thanks

If it will work with only 2 wires, connect one to the RH, and the other to the W. It might be best if you checked to see which one connected to the R terminal at the furnace or directly to the transformer and made it the one connected to RH. See
https://www.askmehelpdesk.com/heating-air-conditioning/common-thermostat-questions-40771.html

It may need batteries for power.

Labman thanks for your reply, there is no RH on the RTH7000, its labeled C, G, Y, W, RC, R, PLEASE ADVISE

OK the red wire goes to R. If you have A/C, but only one transformer, jumper R to RC.

I don't have a/c its just a oil burner, so are you saying that I should connect the Green(ground wire) to C and the brown(hot wire) to R, then should I remove the jumper that connects Rc to R?

I dont have a/c its just a oil burner, so are you saying that I should connect the Green(ground wire) to C and the brown(hot wire) to R, then should I remove the jumper that connects Rc to R?
Just connect one wire to R it doesn't matter if jumper is there for R-Rc or not. The other wire goes to W.