My existing thermostat is a Janitrol HPT18-60. Wich has 7 connections, and 6 wires... Y-yellow, G-green, R-tan, O-brown, C-blue, and a red wire connecting an E and W2. I'd like to replace it w/ a Honeywell RTH230B. Wich has... Rh, Rc, W, Y, and G. However, I cannot find a wiring schematic, for the Janitrol, to tell me what each connection is for. WHAT DO I DO??