AboutJ Cook Expertise With 25+ years experience, I am familiar with residential, commercial, and industrial HVAC equipment including but not limited to boilers, chillers, reciprocating and screw compressors. I am trained in all manners of control wiring.
Experience I currently have three HVAC licenses and Refrigeration license by the State of North Carolina. I have been in this field for over twenty years. I have been a service technician for a contractor and also worked at a state college in the repair and maintenance of steam lines and equipment. I am currently the Building Maintenance Superintendent for a municipality.
Question I am replacing a standard thermostat (FHP Manufacture, Simple comfort)with a Honeywell Focus Pro6000,TH6110D10039, Programmable thermostat. The 5 year old HVAC system is an "Earth Energy" geo-thermal water system in an apartment building. The wiring on the original thermostat is:G-green, O-orange, Y and W with jumper-yellow, C-black, and R-red. When I installed the new thermostat the wiring was G-green, O/B-orange, C-black, Y-yellow, R and Rc with a jumper-red. The fan would not start. Since this is a heat-pump only system there is not any supplemental heat source. The fan starts almost instantly with the original thermostat. Any ideas on how I should proceed. Thanks, Jim"
Answer All of the wiring is correct Jim. With an O terminal, this stat is specifically for a heat pump and the fan should start immediately as it did with the old stat. The G terminal is the fan circuit. You can test this circuit by turning the unit power off, removing the front section of the stat exposing the sub base with the attached wiring. The R terminal is the switching leg of the 24 volts and install a jumper from R to G and turn the power back on and see if the fan starts immediately. If so, there may be some switches or programming in the stat delaying the fan. Thanks J
