I am replacing my Rudd thermostat which has a White (E), Red (R), Green (G), Yellow(Y) Blue (B) and brown (X) wires coming from the wall. I am replacing it with a Honeywell RTH2410 thermostat which has O/B, Y, R, G and W/AUX connectors. The Y, R, W and G connections are easy. But what happens to the blue and brown wires?

Thank you!

Blue to o, brown to L or not used.

Thank you!