Heating System Table
Note: Setting the screw “out one turn” means turning the screw 360°
Type of system | Screws A and B | Fuel switch |
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Warm air, gas, or oil heating system with an efficiency rating under 90%. | Use factory setting | F |
(The furnace efficiency rating should be on the furnace.) |
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F | ||
Utilization Efficiency) unit |
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Hot water boiler | F | |
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Electric furnace | E | |
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Step 5. Wire the thermostat terminals
Fig. 9
G
Y
W
R
a.Hold the thermostat as shown in Fig. 9.
b.Using the labels on the wires, match the letter of your old thermostat wire with the corresponding terminal on the back of your new thermostat.
Note: If the letters on the old thermostat terminals do not match the letters on the new thermostat terminals, you might not need to connect all of the old wires to the new thermostat. See the special wiring instructions on page 9 for details.
c. Loosen the terminal screws and slip each wire beneath its
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| M20125 | matching terminal (Fig 10). |
Fig. 10 |
| INSERT |
| d. Securely tighten the terminals. |
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| 5/16 in. | STRAIGHT |
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| UNDER |
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| (8 mm) |
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| SCREW HEAD |
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| STRIP |
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END OF WIRE
VISIBLE HERE
M20126
INSTALLATION 7 |