Emerson 850 Mounting And Wiring, Electric Heat or Single Stage Heat Pump Systems

3 REMOVING OLD THERMOSTAT

CONTINUED FROM FIRST PAGE

ATTENTION! This product does not contain mercury. How- ever, this product may replace a unit which contains mercury.

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 container which can be sealed. If a cell becomes damaged, the unit should be discarded.

Mercury must not be discarded in household trash. When the unit this product is replacing is to be discarded, place in a suitable container and return to White-Rodgers for proper disposal.

4 MOUNTING AND WIRING

!WARNING

Do not use on circuits exceeding specified voltage. Higher voltage will damage control and could cause shock or fire hazard.

Do not short out terminals on gas valve or primary control to test. Short or incorrect wiring will damage thermostat and could cause personal injury and/or property damage.

Thermostat installation and all components of the sys- tem shall conform to Class II circuits per the NEC code.

Electric Heat or Single Stage

Heat Pump Systems

This thermostat is configured from the factory to operate a heat/ cool, fossil fuel (gas, oil, etc.), forced air system. It is configured correctly for any system that DOES NOT require the thermostat to energize the fan on a call for heat. If your system is an electric or heat-pump system that REQUIRES the thermostat to turn on the fan on a call for heat, locate the GAS/ELECTRIC switch (see fig. 1) and switch it to the ELECTRIC position. This will allow the thermostat to energize the fan immediately on a call for heat. If you are unsure if the heating/cooling system requires the thermostat to control the fan, contact a qualified heating and air conditioning service person.

Hydronic (Hot Water or Steam)

Heating Systems

This thermostat is set to operate properly with a forced-air heating system. If you have a hydronic heating system (a system that heats with hot water or steam), you must set the thermostat to operate properly with your system. Change the second option in the configuration menu to SL (see CONFIGURATION MENU, page 5).

!CAUTION

Take care when securing and routing wires so they do not short to adjacent terminals or rear of thermostat. Personal injury and/or property damage may occur.

TERMINAL CROSS REFERENCE CHART

New Thermostat		Other Manufacturers’
Terminal Designation		Terminal Designation
RH	4	RH	M	*	*
				R5	R
RC	R	R	V	-	-
G	G	G	F	G	G
W	W	W	H	4	W
Y	Y	Y	C	Y6	Y

*These are four-wire, single-transformer systems. Factory installed jumper wire between the RH and RC terminals must remain in place.

Attach Thermostat Base to Wall

1.Remove the packing material from the thermostat. Gently pull the cover straight off the base. Forcing or prying on the thermostat will cause damage to the unit. If necessary, move the electric heat switch (see ELECTRIC HEAT SYSTEMS, above).

2.Connect wires beneath terminal screws on base using appro- priate wiring schematic (see figs. 2 through 7).

3.Place base over hole in wall and mark mounting hole locations on wall using base as a template.

4.Move base out of the way. Drill mounting holes.

5.Fasten base loosely to wall, as shown in fig. 1, using two mounting screws. Place a level against bottom of base, adjust until level, and then tighten screws. (Leveling is for appear- ance only and will not affect thermostat operation.) If you are using existing mounting holes, or if holes drilled are too large and do not allow you to tighten base snugly, use plastic screw anchors to secure base.

6.Push excess wire into wall and plug hole with a fire-resistant material (such as fiberglass insulation) to prevent drafts from affecting thermostat operation.

Battery Location

This thermostat requires 2 “AA” alkaline batteries to operate. If the word LO BATTERY is displayed, the batteries are low and should be replaced with fresh “AA” Energizer® alkaline batteries. To replace the batteries, install the batteries along the top of the base (see fig. 1). The batteries must be installed with the positive(+) ends to the right.

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