Honeywell T8090A User Manual

TRADELINE

and Heating-Cooling Thermostat,

T8090A Heating, Cooling,

Wallplate and Subbase

Preparation

Check thermostat and subbase (if used) suitability for the heating, cooling, or heating/cooling system. Refer to Table 1.

Assemble tools required: flat bladed screwdriver, hand or power drill with 3/16 in. drill bit, wire cutter/stripper or sharp knife, bubble level or plumb bob and line.

TABLE 1—SYSTEM COMPATIBILITY FOR NON-BATTERY POWERED THERMOSTATS.

Type of Heating System to be Controlled Conditions/Compatibility

Electric (Line Voltage)—Typical baseboard and radiant

Fan Coil Unit • Compatible. Assure correct subbase identity selected for

Gas—Direct Spark Ignition (DSI), Intermittent Pilot (IP), and Standing Pilot (SP)

Heat Pump • Compatible. Assure correct subbase identity is selected

Hot Water Zone • Honeywell 2-wire valves are compatible.

Oil • If not using battery backup, assure that the 24V control

Vent Damper • Honeywell damper motors are compatible.

Warm Air Zone • Most are compatible.

If thermostat is not compatible with the system being controlled, the system will not operate. No hazard exists. The thermostat will not be damaged unless it is used to directly control a line voltage system. For proper system operation, a Honeywell R841 or R8239D1015 Isolating Relay must be added to the thermostat control circuit.

Cut the two black heat anticipator jumper wires before installing the thermostat. See Set Heat Anticipator section.

Consult manufacturer for installation requirements.

• The R8239D1015 Isolating Relay or R841 Silent

• Compatible. If not using battery backup, assure that the

• Some non-Honeywell 2-wire valves will require an

• Some 3-wire valves will require an R8239A1052

• Some non-Honeywell damper motors will require an

Assure power is off to the heating, cooling, or heating/ cooling system at the main fuse panel. Most buildings have a separate switch box or circuit breaker for disconnecting power to the heating and cooling (if applicable) equipment.

This thermostat is compatible with all heating, cooling or heating/cooling systems when thermostat is powered by batteries. If thermostat is not powered by batteries, refer to Table 1 for thermostat and system compatibility information.

Switching Center must be installed in the thermostat control circuit.

fan control.

24V control transformer common is accessible for connection to thermostat cable conductor and power to the transformer is not regularly interrupted by high temperature or limit operation.

for fan control and changeover control (O terminal for cool and B terminal for heat).

R8239D1015 Isolating Relay in the thermostat control circuit.

Isolating Relay in the thermostat control circuit.

transformer common is accessible for connection to thermostat cable conductor and power to the transformer is not regularly interrupted by high temperature, purge cycle, or limit operation.

R8239D1015 Isolating Relay in the thermostat control circuit.

a,b

Check control amperage requirement.

a,c,b

D.F. • Rev. 10-94 • • ©Honeywell Inc. 1994 • Form Number 69-0750—1

1 69-0750—1

M3375

Recycling Notice

This control contains mercury in a sealed tube. Do not

place control in the trash at the end of its useful life.

If this control is replacing a control that contains mer-

cury in a sealed tube, do not place your old control in the trash.

Contact your local waste management authority for instructions regarding recycling and the proper disposal of this control, or of an old control containing mercury in a sealed tube.

If you have questions, call Honeywell Inc. at 1-800468-1502.

Installation

WHEN INSTALLING THIS PRODUCT…

1. Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.

2. Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.

3. Installer must be a trained experienced service technician.

4. After installation is complete, check out product operation as provided in these instructions.

CAUTION

1. Disconnect power supply to prevent electrical shock or equipment damage.

2. Run wires as close as possible to the subbase. To prevent interference with the thermostat linkage, keep wire length to a minimum. Push excess wire back into the hole and plug hole to prevent drafts from affecting thermostat operation.

3. Do not overtighten thermostat captive mounting screws because damage to subbase threads may result.

4. Do not short across coil terminals on relay; this may burn out the heat anticipator.

LOCATION

Locate thermostat about 5 ft [1.5m] above the floor in an area with good air circulation at average temperature. Do not mount the thermostat where it may be affected by:

— drafts, or dead spots behind doors and in corners.

— hot or cold air from ducts.

— radiant heat from the sun or appliances.

— concealed pipes and chimneys.

— unheated (uncooled) areas behind the thermostat.

Run wires from the heating, cooling or heating-cooling equipment to the new thermostat location.

The number of wires required to connect this thermostat to the heating, cooling or heating-cooling equipment depends on how the thermostat is powered—by the 24 Vac or battery, or through the control system. Refer to the Typical Wiring Diagrams section to determine the number of wires required for your application.

UNPACK THERMOSTAT

Handle your new thermostat carefully; rough handling may interfere with its accuracy. Before unpacking, refer to Fig. 1.

Remove and discard the shipping wrap.

IMPORTANT: Save package of screws and instructions

for the homeowner.

Fig. 1—Unpack thermostat.

THERMOSTAT COVER

THERMOSTAT BASE

CAPTIVE MOUNTING SCREWS

LIFT COVER

M1518

Remove the thermostat cover by lifting from the bottom. Set aside cover until needed later.

Carefully remove the material protecting the mercury switch bulb.

Loosen two captive mounting screws and separate the wallplate (if provided) from the back of the thermostat base.

MOUNT WALLPLATE OR SUBBASE Wall Mounting (See Fig. 2)

Hold the wallplate or subbase in position on the wall. See Fig. 2.

Mark holes on the wall for anchors. Use the spirit level to make sure the wallplate or subbase is level.

Drill 3/16 in. holes and gently tap the anchors into the holes until flush with the wall.

Pull wires through the large wiring hole in the wallplate or subbase.

Loosely fasten the wallplate or subbase to the wall with the three screws. Do not tighten the screws completely.

Carefully level the wallplate or subbase and firmly tighten the screws. See Fig. 3.

Outlet Box Mounting (See Fig. 4)

Use a horizontally mounted outlet box if possible. If a vertical outlet box is used, mount the wallplate or subbase on a 193121A (beige) or 202689A (white) Cover Plate Assembly (ordered separately). Follow the instructions provided with the cover plate assembly.

Align wallplate or subbase mounting holes on the outlet box and loosely fasten with two screws.

Carefully level the wallplate or subbase and firmly tighten the screws. See Fig. 3.

69-0750—1 2

Fig. 2—Mounting wallplate or subbase to wall.

3 SCREW HOLES WITH PLASTIC ANCHORS

HEATING-ONLY WALLPLATE

FAN

HEATING/COOLING SUBBASE

Fig. 3—Leveling methods for wallplate or subbase.

AUTO OFF

HEATON

COOL

PLUMB BOB OR WEIGHT

PLUMB LINE

M1552A

FAN

AUTO OFF

Fig. 4—Mounting wallplate or subbase on horizontal outlet box.

3 SCREW HOLES WITH PLASTIC ANCHORS

SPIRIT LEVEL

COOL

HEATON

M857

M1555

EXISTING HORIZONTAL OUTLET BOX

FAN

AUTO OFF

HEATON

HEATING/ COOLING SUBBASE

COOL

M1553A

VERTICAL OUTLET BOX

NOT INCLUDED WITH UNIT.

ACCESSORY PARTS AVAILABLE.

EXISTING HORIZONTAL OUTLET BOX

HEATING-ONLY WALLPLATE

M856A

SUBBASE OR WALLPLATE

ADAPTER RING

MOUNTING SCREWS (2)

COVER PLATE

M1554A

3 69-0750—1

+ 7 hidden pages