Instructions for the Aprilaire 8840 Series communicating thermostat system are found in a separate document (DP 10004345). A portion of the command set is found in Appendix 2 in this manual. For a complete command set with programming suggestions, see the programming manual (DP 10005756). Contact Research Products Corporation for these documents at 888-782-8638. THERE ARE 14 STEPS INVOLVED IN THE INSTALLATION OF A COMPLETE SYSTEM. Step 1 GET ALL THE COMPONENTS YOU WILL NEED 1 Step 2 DISCONNECT P