I am replacing a Janitrol HPT18-60 with a Honeywell RTH110B thermostat. I hooked up all the wiring accordingly with the 5-wire diagram as I have all five wires (y,g,r,b,w) and the heat will work, but the cooling will not. I have an outside heat pump. I also live in a mobile home if that makes a difference. Supposedly this model thermostat is good for single and multi stage units. I am new at all this and would appreciate the help.

Check the box for the stat, I don't believe you bought one that works with a heat pump. Take it back and ask for one that works on a heat pump.