Apr 14, 2023
Troubleshooting Communication Issues With Observer System
•Where do you start?
–Be sure you haven’t criss-crossed any wires
•If the Green and Yellow communication wires are reversed, communication may not work
•Make sure all wire connections are secure
Remeber R-R, C-C, (DX+)-(DX+), (DX-) - (DX-)
Make sure wire twisting is tight- Example below we want the Yellow wire look...

–Disconnect all accessories
•Humidifier
•Ventilator
–Check for float switches
•Condensate Pump
•Drain pan overflow switch
–Shielded wire may be necessary
•“Noisy” areas can cause communication problems
•Fluorescent lighting ballasts
•Near or with security wiring
In a conduit with high voltage wiring
Remember to ground cable at one end only, other the shield becomes an antenna for all sorts of signals
•Make sure your wires are connected properly
–Check wires in screw terminal strips, loose connections can cause comm. issues
–Look for wire nuts/splices in wiring between indoor & outdoor units
–Wires run in a wall can be nicked by a nail or screw
–Look for indications of water on control boards, blower motors, etc.
•Fan coil boards will sweat in the summer if the thermostat wire entry point is not properly sealed
•There may be a power supply problem
–Check for insufficient VA from the transformer to power zoning system communication bus, and all other system accessories
–This is especially likely when multiple CTS (color touch screen) display are used for zone sensors
–If necessary, add a field-supplied transformer for the Observer System communication bus…
Alternate Zone Panel Power:
Field Supplied 120, 208/230 V - 24 V - 60VA Transformer
Transformer will power the panel using R & C (C will be tied back to the inside communicating equipment) DX+ & DX- will be hooked up between inside communicating equipment & Observer® zone panel.

•AC or HP can’t communicate
–Take the Observer® control out to the AC or HP and connect to the Furnace using the DX+, DX-, R, C wires. If it communicates, you know the wire is okay. If not, there may be a problem in the wire running between the AC or HP and the furnace
•Furnace can’t communicate
–Disconnect the wires going outside to the AC or HP
–Disconnect the wires going from the furnace to the wall plate where the wall control is mounted
–Connect the Observer control to the furnace using a short piece of wire
–Be sure the furnace DIP switches are all in the correct position (switch 4-1 in the on position disables the communication relay)
–Make sure the furnace is not in test mode (DIP switches)

