70810-IM 12/21/06 2:52 PM Page 1 ® Model 70810 INSTALLATION AND OPERATING INSTRUCTIONS 5-2 Programmable Electronic Thermostat Heat/Cool
70810-IM 12/21/06 2:52 PM Page 2 Compatible with low voltage single stage gas, oil or electric heating or cooling systems and single stage heat pumps. For use on 24VAC systems (not to exceed 30VAC) and 250mv to 750mv millivolt heating only systems. WARNING! • To prevent electrical shock and/or equipment damage, disconnect electric power to system at main fuse or circuit breaker box until installation is complete. • Do not use this thermostat on applications with voltages above 30VAC.
70810-IM 12/21/06 2:52 PM Page 3 Removing The Existing Thermostat 1) CAUTION: Make certain the power to the system has been disconnected. 2) Remove the cover of the old thermostat and locate the wires that are connected to the terminal board. IMPORTANT: Before removing these wires, NOTE (ON A PIECE OF PAPER) THE COLOR OF EACH WIRE AND THE CORRESPONDING TERMINAL MARKING ON THE OLD THERMOSTAT. 3) Remove the wires from the terminals. Remove the old thermostat and mounting base from the wall.
70810-IM 12/21/06 2:52 PM Page 4 9) Carefully place the thermostat body face down on a soft surface to expose the main circuit board. Gently set the following switches in the correct position for the application. • GAS / ELECTRIC: Configures the thermostat to either gas/oil or electric heating systems. For electric, se the switch to HE. For gas, set the switch to HG. • C / F: Sets the display in either Celsius or Fahrenheit.
70810-IM 12/21/06 2:52 PM Page 5 2) Set the fan switch to the ON position. The system blower should start. 3) Set the fan switch to the AUTO position. The system blower should stop. 4) Set the system switch to the HEAT position and depress the red arrow key until the temperature set point is at least 3 degrees above the room temperature. The LCD will display a flame icon to indicate heat. The heating system should start within several seconds (the system blower may not come on immediately).
70810-IM 12/21/06 2:52 PM Page 6 2) When the desired setting is made, release the key and the unit will automatically store the setting after 15 seconds. Programming & Operating The New Thermostat Setting the Time & Day 1) With the thermostat in set at either COOL, OFF, or HEAT, depress the TIME/DAY key. The hour will flash. Using the red/blue arrow keys, set the correct hour. 2) Depress the TIME/DAY key a second time. The minutes will flash. Using the red/blue arrow keys, set the correct minutes.
0810-IM 12/21/06 2:52 PM Page 7 Customizing the Program 1) Set the System switch to the HEAT or COOL position and the Fan switch to either the AUTO or ON position. NOTE: In AUTO, the system blower will run only when the A/C or heat is running. In ON, the system blower will operate continuously. 2) Depress the PROGRAM key. LCD will display an image similar to the following. The set point temperature will blink and the time will be displayed.
70810-IM 12/21/06 2:52 PM Page 8 Vacation Hold 1) The thermostat can be set to hold a single specific temperature for up to 30 consecutive days. Upon activation, the thermostat will hold the temperature until the duration period times out at which point the thermostat will return to program mode. To activate this feature, depress the VACATION key. The LCD will display the duration in days and the set point temperature. Image shows 1 day hold at 73 F Image shows 25 day hold at 71 F.
70810-IM 12/21/06 2:52 PM Page 9 • Compressor Protection: To protect the system compressor(s) from damage, the thermostat features a 5 minute delay. After the cooling system (or heat pump turns off), the thermostat will not allow it to re-start until the 5 minute delay expires. A blinking snowflake/flame indicates this feature has been activated. Once the 5 minute delay expires, the snowflake/flame will illuminate continuously and the system will be able to re-start when called upon.
70810-IM 12/21/06 2:52 PM Page 10 Troubleshooting SYMPTOM CORRECTIVE ACTION Display is blank Check thermostat wiring & connections. Check circuit breaker/fuse panel. No heat Set system switch to HEAT and raise set point above room temperature. If flame icon is blinking, allow the 5 minute compressor lock-out to expire. Check thermostat wiring and connections. Check pilot light or HSI system on furnace. No cool Set system switch to COOL and lower set point below room temperature.
70810-IM 12/21/06 2:52 PM Page 11 Wiring Diagrams Install Jumper RC RH Typical 4-Wire System C G Y FAN CONTROL W HEAT CONTROL COOL CONTROL HOT 24 VAC TRANSFORMER COM 11 B O
70810-IM 12/21/06 2:52 PM Page 12 Wiring Diagrams Typical 5-Wire System RC RH C HOT G Y FAN CONTROL COOL CONTROL COOL 24 VAC TRANSFORMER 12 W HOT COM B O HEAT CONTROL HEAT 24 VAC TRANSFORMER COM
70810-IM 12/21/06 2:52 PM Page 13 Wiring Diagrams Typical 2-Wire Millivolt System RC RH C G W Y B O HEAT CONTROL HOT 13 24 VAC TRANSFORMER COM
70810-IM 12/21/06 2:52 PM Page 14 Wiring Diagrams Typical Single Stage Heat Pump System RC RH Install Jumper C G W Y FAN CONTROL B Install Jumper COMPRESSOR CONTROL HOT 24 VAC TRANSFORMER 14 O REV. VALVE COOL ENERGIZED REV.
70810-IM 12/21/06 2:52 PM Page 15 Warranty ONE YEAR LIMITED WARRANTY Motors & Armatures Inc. warrants each new MARS thermostat against any defects due to non-conforming material or workmanship for a period of one year after the original date of purchase by a professional service technician and does not include the cost of removal or re-installation. This warranty extends to the contractor or dealer who purchased the product from a wholesaler.
70810-IM 12/21/06 2:52 PM Page 16 INSTALLATION AND OPERATING INSTRUCTIONS 5-2 Programmable Electronic Thermostat Heat/Cool Model 70810 ®
