installing a new thermostat for Lux model DMH110. I have 5 wires; red, blue, yellow, white and green. The model shows letters, am I to connect the wires to the letters; Y for yellow, etc. Not sure where to connect the red wire. The thermostat has a RH and a RC indicator. The it also shows and O and a C. Email address is Sandra.Snyder@Supervalu.com or phone # is 630-945-6327. Thank you