Summary of the content on the page No. 1
CONTENTS
Preparations .................................................. 1
Thermostat Details ........................................ 1
Installation Instructions for
Removing Old Thermostat ............................ 1
Mounting and Wiring ..................................... 2
Heating & Cooling
Check Thermostat Operation ........................ 4
Specifications ................................................ 7
Digital Model 850
Troubleshooting ............................................ 7
Summary of the content on the page No. 2
REMOVING OLD THERMOSTAT 3 CAUTION ! CONTINUED FROM FIRST PAGE Take care when securing and routing wires so they do ATTENTION! This product does not contain mercury. How- not short to adjacent terminals or rear of thermostat. ever, this product may replace a unit which contains mercury. Personal injury and/or property damage may occur. Do not open mercury cells. If a cell becomes damaged, do not touch any spilled mercury. Wearing non-absorbent gloves, take up the spilled mercury and place into a
Summary of the content on the page No. 3
MOUNTING AND WIRING 4 CONTINUED FROM SECOND PAGE THERMOSTAT ‡ C B O Y G W RC RH SYSTEM Hot JUMPER Cooling Fan Heating WIRE 24 VAC 120 VAC System Relay System THERMOSTAT ‡ Neutral C B O Y G W RC RH SYSTEM HEATING TRANSFORMER Fan Heating Hot Relay System Hot 24 VAC 120 VAC 24 VAC 120 VAC NOTE Neutral Neutral For 2-wire Heat only, COOLING TRANSFORMER attach to RH and W TRANSFORMER Figure 5. Typical wiring diagram for Figure 2. Typical wiring diagram for heat/cool, 5-wire, two-transformer systems h
Summary of the content on the page No. 4
CHECK THERMOSTAT OPERATION 5 If at any time during testing your system does not operate properly, contact a qualified service person. Turn on power to the system. Fan Operation If your system does not have a G terminal connection, skip to Heating System. 1. Move FAN switch to ON position. The blower should begin to operate. 2. Move FAN switch to AUTO position. The blower should stop immediately. Heating System 1. Move SYSTEM switch to HEAT position. If the heating system has a standing pilot, be
Summary of the content on the page No. 5
5) Select filter replacement run time - The thermostat will CHECK THERMOSTAT OPERATION 5 display “FLTR” after a set time of operation. This is a reminder to change or clean your air filter. This time can be CONTINUED FROM FOURTH PAGE set from 0 to 1950 hours in 50 hour increments. A selection 1) Select Temporary Hold Time - The thermostat can hold any of 000 will cancel this feature. When “FLTR” is displayed, temperature you set it to for the amount of time you select on you can clear it by pres
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Set Current Time and Day CHECK THERMOSTAT OPERATION 5 1. Press TIME button once. The display will show the hour only. CONTINUED FROM FIFTH PAGE • HOLD TEMPERATURE — The thermostat can hold any PM EXAMPLE: temperature within its range for an indefinite period without reverting to the programmed temperature. Momentarily press 2. Press and hold either or until you reach the correct HOLD button. HOLD will be displayed. Then choose the hour and AM/PM designation (AM begins at midnight; PM desired
Summary of the content on the page No. 7
1. Move SYSTEM switch to COOL position. PROGRAMMING YOUR THERMOSTAT 6 2. Follow the procedure for entering your heating program, using CONTINUED FROM SIXTH PAGE your selected cooling times and temperatures. 7. Repeat steps 3 through 5 for the 3rd and 4th heating program Check Your Programming periods. Weekday heating programs are now complete. Follow these steps to check your thermostat programming one 8. Press PRGM once. “SA” will appear in the display, along with final time before beginning th
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TROUBLESHOOTING 8 CONTINUED FROM SEVENTH PAGE Symptom Possible Cause Corrective Action No Heat (continued) 5. Heating system requires service or Diagonistic: Set SYSTEM Switch to HEAT and thermostat requires replacement. raise the setpoint above room temperature. Within a few seconds the thermostat should make a soft click sound. This sound usually indicates the thermostat is operating properly. If the thermostat does not click, try the reset operation listed below. If the thermostat does not cl
