70801-IM 12/14/06 3:06 PM Page 1 ® Model 70801 INSTALLATION AND OPERATING INSTRUCTIONS Non-Programmable Electronic Thermostat Heat/Cool
70801-IM 12/14/06 3:06 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.
70801-IM 12/14/06 3:06 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.
70801-IM • • • 10) 11) 12) 13) 12/14/06 3:06 PM Page 4 GAS / ELECTRIC: Configures the thermostat to either gas/oil or electric heating systems. C / F: Sets the display in either Celsius or Fahrenheit. NORM / HP: Configures the thermostat for normal heating/cooling systems or heat pump systems (single stage). Attach the thermostat body to the back plate by resting the top of the thermostat body on the two clips on the upper portion of the back plate.
70801-IM 12/14/06 3:06 PM Page 5 5) Set the system switch to the OFF position. The system should shut down within several seconds. The LCD will again display only the room temperature. 6) Set the system switch to the COOL position and depress the blue arrow key until the temperature set point is at least 3 degrees below the room temperature. The LCD will display a snowflake icon to indicate A/C. The cooling system should start within several seconds.
70801-IM 12/14/06 3:06 PM Page 6 Operating The New Thermostat 1) Set the System switch to either 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) Use the red and blue arrow keys to select the desired temperature set point.
0801-IM 12/14/06 3:06 PM Page 7 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. 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 If snowflake is blinking, allow the 5 minute compressor lock-out to expire.
70801-IM 12/14/06 3:06 PM Page 8 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 8 B O
70801-IM 12/14/06 3:06 PM Page 9 Wiring Diagrams Typical 5-Wire System RC RH C HOT G Y FAN CONTROL COOL CONTROL COOL 24 VAC TRANSFORMER W HOT COM 9 B O HEAT CONTROL HEAT 24 VAC TRANSFORMER COM
70801-IM 12/14/06 3:06 PM Page 10 Wiring Diagrams Typical 2-Wire Millivolt System RC RH C G W Y B O HEAT CONTROL HOT 24 VAC TRANSFORMER COM 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 10 O REV. VALVE COOL ENERGIZED REV.
70801-IM 12/14/06 3:06 PM Page 11 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.
70801-IM 12/14/06 3:06 PM Page 12 INSTALLATION AND OPERATING INSTRUCTIONS Non-Programmable Electronic Thermostat Heat/Cool Model 70801 ®