Honeywell T841A1308 Thermostat User Manual

Home

href="
T841A Heating-Cooling  
Heat Pump Thermostat  
INSTALLATION INSTRUCTIONS  
APPLICATION  
The T841A Heating-Cooling TRADELINE® Thermostat  
provides 24 Vac control of two-stage heating and one-  
stage cooling in heat pump systems, using manual  
changeover. This thermostat provides SYSTEM switch  
selections of EM. HEAT-HEAT-OFF-COOL and FAN  
switch selections of AUTO-ON. See Fig. 1. See Table 1 for  
T841A TRADELINE® specifications.  
Test holes are provided on the front of the thermostat to  
accommodate test meter probes without removing the  
thermostat from the wall. Remove the cover of the  
thermostat to expose the test holes, which are labeled to  
correspond with the terminals on the back of the  
thermostat.  
Table 1. T841A TRADELINE® Specifications.  
Auto Fan  
in EM.  
HEAT  
No  
LED  
Indication  
Heat  
Anticipation Designations  
Stage 2 fixed, G, R, W , E,  
Terminal  
System  
Switch  
OS Number  
Changeover  
Manual Cool  
or Heat  
Remarks  
a
T841A1308  
EM. HEAT ,  
AUX. HEAT  
2
Use when E  
and W are  
2
jumpered.  
EM. HEAT,  
HEAT, OFF,  
COOL  
0 to 1.5A  
L, B, X, Y, O  
T841A1316  
G, R, E, L, X  
Does not  
Yes  
W
2
, B, W1,  
replace  
Y
1
, O  
T841A1068.  
Not for systems  
b
T841A1423  
EM. HEAT,  
Stage 2  
W
3
2
, G, R, W ,  
AUX. HEAT,  
CHECK  
adjustable, 0.1 E, L, B, X, Y,  
with E to W  
2
jumper  
d
to 1.2A  
O
b,c  
T841A1464  
T841A1498  
EM. HEAT  
Stage 2 fixed, G, R, W, H, B, Exact  
0
to 1.5A  
X, O, Y  
replacement for  
York model no.  
2TH11703324  
b
T841A1506  
a
b
c
d
EM. HEAT LED also indicates compressor malfunction.  
Premier White® color.  
Sold only in Australia: degrees C.  
CHECK LED indicates compressor malfunction.  
FRONT OF DEVICE  
BACK OF DEVICE  
COVER  
80  
70  
60  
50  
80  
70  
60  
50  
THERMOMETER  
SET POINT  
SCALE  
EM. HEAT HEAT OFF COOL  
FAN AUTO ON  
CHECK  
EM. HEAT AUX. HEAT  
LED (UP  
SYSTEM SWITCH  
FAN SWITCH  
TO THREE)  
MOUNTING  
HOLES (4)  
WIRING TERMINAL  
(UP TO 12)  
M2960A  
Fig. 1. External view of T841A.  
®
U.S. Registered Trademark  
Copyright © 1997 Honeywell Inc. •  
All Rights Reserved  
69-0452-8  
href="
T841A HEATING-COOLING HEAT PUMP THERMOSTAT  
OPERATION  
The stages of heat make sequentially as the temperature  
drops. Make refers to the mercury switch initiating a call for  
heat or cool.  
CAUTION  
1
.
.
Disconnect power supply to prevent electrical  
shock or equipment damage.  
2
To prevent interference with the thermostat  
linkage, keep wire length to a minimum and  
run wires as close as possible to the thermo-  
stat base.  
There is about 1°F (0.6°C) between stages so the second  
stage (auxiliary heat) makes only when the first stage  
cannot handle the load. This 1°F is the interstage differen-  
tial.  
3.  
4.  
5.  
Do not overtighten the thermostat captive  
mounting screws, because damage to the  
threads can result.  
Do not short across coil terminals on the relay.  
This can burn out the thermostat heat  
anticipator.  
Never install more than one wire per terminal  
unless a factory-supplied jumper with spade  
terminal is used.  
The LED indicators on certain thermostat models light up  
when something specific happens within the system.  
When the green or amber LED lights, the auxiliary heat  
(
second stage heat) is operating because the weather is  
so cold, the heat pump alone cannot handle the load.  
When the red EM. HEAT LED lights, the emergency heat  
is operating (usually electric strip heaters), because the  
homeowner has physically switched to the EM. HEAT  
position. See heating/cooling manufacturer instructions for  
specific meaning.  
Location  
Locate the thermostat about 5 ft (1.5m) above the floor in  
an area with good air circulation at average room tempera-  
ture.  
RECYCLING NOTICE  
This control contains mercury in a sealed tube. Do  
not place the control in the trash at the end of its  
useful life. If this control is replacing a control that  
contains mercury in a sealed tube, do not place  
your old control in the trash.  
Do not mount the thermostat where it can be affected by:  
drafts, or dead spots behind doors and in corners.  
hot or cold air from ducts.  
radiant heat from sun, appliances or fireplaces.  
concealed pipes and chimneys.  
unheated (uncooled) areas such as an outside wall  
behind the thermostat.  
Contact your local waste management authority for  
instructions regarding recycling and the proper  
disposal of this control, or any control containing  
mercury in a sealed tube.  
This thermostat is a precision instrument and was carefully  
adjusted at the factory. Handle it carefully.  
Mounting and Wiring  
CAUTION  
Disconnect power supply before beginning  
installation. Can cause electrical shock or  
equipment damage.  
INSTALLATION  
The T841A can be mounted directly to a wall or  
horizontal outlet box. Choose the method that best fits  
your installation.  
When Installing this Product…  
1.  
Read these instructions carefully. Failure to follow  
them could damage the product or cause a hazard-  
ous condition.  
In replacement applications, check the existing thermostat  
wires for cracked or frayed insulation. Replace wires in  
poor condition.  
2.  
Check the ratings given in the instructions and on  
the product to make sure the product is suitable for  
your application.  
All wiring must comply with local codes and ordinances.  
3
4
.
.
Installer must be a trained, experienced technician.  
After installation is complete, check out product  
operation as provided in these instructions.  
69-0452—8  
2
href="
T841A HEATING-COOLING HEAT PUMP THERMOSTAT  
Grasp the thermostat cover at the top and bottom with one  
hand. Pull outward on the bottom edge of the cover until it  
snaps free of the thermostat base. Carefully remove and  
save the packing material surrounding the mercury  
switches.  
SETTINGS  
Heat Anticipator Setting  
The second stage heat anticipator is adjustable. Move the  
adjustable indicator to match the current draw of the  
second stage heating primary control, or the anticipator  
setting of the old thermostat. See Fig. 6.  
1
.
Run the wiring (if necessary) to the location. If the  
wiring is plastered into the wall, make a hole next to  
the cable and loosen the wires so that they can be  
pushed back into the wall later. Thread the wires  
through the hole in the packing material saved  
above. Connect the wires to the terminals on the  
back of the thermostat. See Fig. 2 through 5.  
Set the second stage adjustable heat anticipator to  
match the current draw of the primary heating  
control (see Heat Anticipator Setting section).  
Push the excess wire back through the hole and  
plug any opening with packing material to prevent  
drafts that may affect thermostat performance.  
Use screws to loosely secure the thermostat to the  
wall or outlet box through the two mounting holes in  
the middle of the device.  
Temperature Setting  
Move the setpoint lever to the desired control point on the  
temperature scale.  
2.  
3.  
4.  
SYSTEM Switch Setting  
The SYSTEM switch positions control the system opera-  
tion as follows:  
EM. HEAT: Emergency heat relay is energized. Cooling  
system is off. Compressor is de-energized. Fan runs  
on call for heat if FAN switch is in the AUTO  
position. EM. HEAT LED is on.  
HEAT: Heating system is automatically controlled by  
the thermostat. Cooling system is off.  
OFF: Both the heating and cooling systems are off. If  
the fan is at the AUTO position, the cooling fan is  
also off.  
COOL: Cooling system is automatically controlled by  
the thermostat. Heating system is off.  
The sheetmetal screws included with the thermostat are  
designed for use in plaster walls that do not need anchors.  
IMPORTANT  
An incorrectly leveled thermostat causes  
inaccurate temperature control.  
5
.
Level the thermostat using a spirit level or plumb  
line. Tighten the two mounting screws at the middle  
of the device.  
Install the two screws in the top mounting holes and  
tighten.  
FAN Switch Setting  
AUTO: Fan operates in response to thermostat in both  
heating and cooling.  
6
.
.
ON: Fan operates continuously.  
7
Replace the thermostat cover.  
L1  
(
HOT)  
ODT 1  
L2  
1
RTD 1  
EHR 1  
ODT 2  
RTD 2  
RTD 3  
H1  
C1  
H1 & C1  
ANTICIPATOR  
FALL  
FAN  
SWITCH  
ERH 2  
FAN RELAY  
AUTO  
ON  
G
R
SYSTEM  
MONITOR  
RTD 1  
H2 ANTICIPATOR  
W2  
AUX. HT.  
LED (GREEN)  
E
SYSTEM  
SWITCH  
EM. HEAT  
RELAY  
RD  
H2  
L
EM. HEAT  
FALL  
HEAT  
OFF  
B
EM. HT.  
LED  
2
CHANGEOVER  
RELAY (HEAT)  
COOL  
(RED)  
X
3
COMPRESSOR  
CONTACTOR  
LACO  
CHP  
Y
1
2
3
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
CHANGEOVER  
RELAY (COOL)  
WHEN SYSTEM MONITOR IS CONNECTED TO L TERMINAL, EM. HT.  
LED ALSO INDICATES COMPRESSOR MALFUNCTION.  
O
X TERMINAL MUST BE CONNECTED FOR PROPER OPERATION.  
M1099B  
Fig. 2. Internal schematic and typical wiring diagram for TRADELINE® T841A1308 with EM. HEAT and AUX. HEAT  
LEDs. No fan control in EM. HEAT. Provides heat or cool changeover relay control.  
69-0452—8  
3
href="
T841A HEATING-COOLING HEAT PUMP THERMOSTAT  
L1  
HOT) L2  
(
1
CHANGEOVER  
RELAY (COOL)  
O
L
H1  
FALL  
FAN SWITCH  
AUTO  
C1  
SYSTEM  
MONITOR  
EM. HT.  
LED (RED)  
3
FAN RELAY  
G
R
E
H1 ANTICIPATOR  
C1 ANTICIPATOR  
ON  
4
EM. HT.  
RELAY  
X
AUX. HT.  
LED (GREEN)  
W2  
SYSTEM  
SWITCH  
FALL  
AUX. HT.  
RELAY  
B
H2  
EM. HT.  
HEAT  
CHANGEOVER  
RELAY (HEAT)  
W1  
Y1  
OFF  
2
JUMPER  
HEAT RELAY 1  
COOL  
H2 ANTICIPATOR  
COMPRESSOR  
CONTACTOR  
1
2
3
4
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
REMOVE W1-Y1 JUMPER WHEN HEAT RELAY 1 IS USED.  
WHEN L TERMINAL IS CONNECTED TO SYSTEM MONITOR, EM. HEAT LED ALSO INDICATES COMPRESSOR MALFUNCTION.  
X TERMINAL MUST BE CONNECTED FOR PROPER OPERATION.  
M1103E  
Fig. 3. Internal schematic and typical wiring diagram for SUPER TRADELINE® T841A1316 with AUX. HEAT and  
EM. HEAT LEDs. Provides heat or cool changeover relay control and automatic fan in EM. HEAT mode.  
AUTO  
G
FALL  
C1  
ON  
FAN RELAY  
L1  
(HOT)  
H1  
FAN  
SWITCH  
R
L2  
H1/C1  
ANTICIPATOR  
W
1
HEAT RELAY  
"H" RELAY  
H
2
B
X
SYSTEM  
SWITCH  
EM. HT.  
LED (RED)  
3
H2  
EM. HT.  
HEAT  
OFF  
EM. HT. RELAY  
ANTICIPATOR  
O
Y
CHANGEOVER  
RELAY (COOL)  
FALL  
COOL  
H2  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND  
OVERLOAD PROTECTION AS REQUIRED.  
COMPRESSOR  
CONTACTOR  
M3171B  
2
3
B TERMINAL MUST BE CONNECTED FOR PROPER OPERATION.  
AUTO FAN IN EM. HEAT.  
Fig. 4. Internal schematic and typical wiring diagram for TRADELINE® T841A1498 and T841A1506  
with EM. HEAT LED. Provides cooling changeover relay control.  
69-0452—8  
4
href="
T841A HEATING-COOLING HEAT PUMP THERMOSTAT  
L1  
HOT)  
L2  
(
1
RTD 1  
ODT 1  
EHR 1  
W3  
8
5
RDT 2  
FAN  
SWITCH  
H1  
C1  
RD  
ODT 2  
EHR 2  
FALL  
AUTO  
ON  
H1/C1  
ANTICIPATOR  
RTD 3  
9
3
G
R
FAN REALY  
W2  
4
AUX. HT.  
LED (GREEN)  
RTD 1  
12  
E
EM. HT.  
LED (RED)  
EM. HT. RELAY  
11  
L
H2  
SYSTEM  
SWITCH  
FALL  
2
CHECK  
LED (RED)  
SYSTEM MONITOR  
10  
EM. HT.  
HEAT  
OFF  
B
6
HEAT CHANGE-  
OVER VALVE  
X
Y
COOL  
LACO  
CHP  
COMPRESSOR  
CONTACTOR  
O
COOL CHANGE-  
OVER VALVE  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
AUTO FAN IN EM. HEAT.  
2
M6059C  
Fig. 5. Internal schematic and typical wiring diagram for TRADELINE® T841A1423 and T841A1464 (sold only in  
Australia) with AUX. HEAT, EM. HEAT and CHECK LEDs. Provides heat or cool changeover relay control and  
automatic fan in EM. HEAT mode.  
LONGER  
.
8.6 .4  
EM.HEAT HEAT OFF COOL  
MOVE INDICATOR  
TO MATCH CURRENT  
RATING OF PRIMARY CONTROL  
M2962B  
Fig. 6. Second stage adjustable heat anticipator indicator.  
69-0452—8  
5
href="
T841A HEATING-COOLING HEAT PUMP THERMOSTAT  
CHECKOUT  
Cooling  
Heating  
CAUTION  
Move the SYSTEM switch on the thermostat to HEAT and  
the FAN switch to AUTO. Move the setpoint lever to about  
Do not operate cooling if outdoor temperature is  
below 50°F (10°C). Refer to manufacturer recom-  
mendations.  
1
0°F (6°C) above the room temperature. Heating should  
start and the fan should run. Move the setpoint lever about  
0°F (6°C) below the room temperature. Heating and fan  
1
Move the SYSTEM switch on the thermostat to COOL  
and the FAN switch to AUTO. Move the setpoint lever  
about 10°F (6°C) below the room temperature. Cooling  
and fan should start. Move the setpoint lever about 10°F  
(6°C) above the room temperature. Cooling and fan  
should shut off.  
should shut off.  
NOTE: To prevent compressor short cycling, a minimum-  
off timer may be included to prevent the com-  
pressor from starting for up to five minutes from  
when the thermostat last turned the compressor  
off, or from when the system first received power.  
Fan  
Move the SYSTEM switch to OFF, and the FAN switch to  
ON. The fan should run continuously. Move the FAN  
switch to AUTO. In this position, the fan operates in  
response to the thermostat in both heating and cooling.  
Automation and Control Solutions  
Honeywell International Inc.  
985 Douglas Drive North  
Golden Valley, MN 55422  
Honeywell Limited-Honeywell Limitée  
35 Dynamic Drive  
Scarborough, Ontario M1V 4Z9  
1
69-0452—8 J.S. Rev. 5-97  
www.honeywell.com/yourhome  

Honeywell CT70 Thermostat User Manual

Lux Products RS5000 Thermostat User Manual

Honeywell 8162 Thermostat User Manual

White Rodgers 1F80ST 0471 Thermostat User Manual

Aube TH110A SP P Thermostat User Manual

Emerson 1F83 0422 Thermostat User Manual

Lux Products P521Ua Thermostat User Manual

Honeywell T6811DP08 Thermostat User Manual

Honeywell TH1210DN Thermostat User Manual

White Rodgers 1F71 Thermostat User Manual