ritetemp 8085c User manual

Customer Support: 888-515-2585 or Visit our webiste www.ritetemp-thermostats.com
Printed in China
1-402-005
The 8085C can be used with most 24 volt gas, oil or electric heating and air conditioning systems, heat pumps with or without
auxiliary heat, gas millivolt heating systems, or zoned heating systems using air or water control valves. It cannot be used with
120 volt heating systems. Ask The Home Depot for other thermostats to control those systems.
The 8085c is a very versatile programmable thermostat:
1. The 8085c separately programs each weekday, Sat and Sun for both heat and cool.
2. There are 4 programming periods per day on program (A).
3. In addition, there are 2 or 6 programming periods per day on a 2nd program (B).
4. Each program (A and B) can be programmed separately and easily selected.
5. You can use the built in program for A or B or alter them to suit your life.
6. The programming display and function is so easy to use, it is almost intuitive.
7. You can easily override any program for as little as one period or as long as a
vacation.
The large liquid crystal touch screen display shows: day of the week, time, present
period, present room temperature, target temperature, humidity, and heating or cooling
status. The word FILTER will come on to remind you when the air filter should be changed.
Built in Electro Luminescent backlight gives high visibility of the display in the dark. When using a compressor for heat pump
and/or for air conditioning, a 5 minute delay time protects your compressor from stalling in heat and cool.Two AA batteries are
used to retain your programs and run the thermostat. In addition, the thermostat may be run with AC power if the C wire is
available. The accuracy of the 8085c is +/- 1
o
F with display resolution of .5
o
F. The room temperature can be changed (calibrated)
to match another thermostat or to compensate for a location.
The 8085c has a humidistat built in to measure and display humidity. It also can be programmed to control high humidity, and/or
low humidity (humidifier required).The 8085c changes the time display to daylight time (DST) by the push of a button.
The 8085c is compatible with dual stage heating systems and heat pumps (with or without auxiliary heat). It also displays the
status of each stage of these systems. If using a heat pump with (expensive) electric auxiliary heat, the 8085c allows you to
choose comfort vs efficiency depending on your location.
8085C Features
RESET
MENUPROGRAM
Install guide 8085C
ENGLISH
RESET
MENUPROGRAM

PG 1
PG 2
Install guide 8085C
1 Location
Caution
Tools
To avoid electrical shock and to prevent damage to the furnace, air conditioner,
and thermostat, disconnect the power supply before beginning work.
This can be done at the circuit breaker, or at the appliance.
C A U T I O N
• Your thermostat is a precise instrument.
• Please handle it with care.
• Turn off electricity to the appliance before installing or
servicing thermostat or any part of the system. Do not turn
electricity back on until work is completed.
• Do not short (jumper) across electric terminals at control
on furnace or air conditioner to test the system.
• This will damage the thermostat and void your warranty.
• All wiring must conform to local codes and ordinances.
• This thermostat is designed for use with 24 volt AC and
millivolt systems. The thermostat should be limited to a
maximum of 1.0 amps; higher amperage may cause
damage to the thermostat.
• On replacement installations, mount the new thermostat in place of the old
one if possible.
• On new Installations, follow the guidelines listed below.
• Locate the thermostat on an inside wall, about 5 ft. (1.5m) above the floor,
and in a room that is used often.
• Do not install it where there are unusual heating conditions, such as: in
direct sunlight; near a lamp, radio, television, radiator register, or fireplace;
near hot water pipes in a wall; near a stove on the other side
of a wall.
• Do not locate in unusual cooling conditions, such as: on a wall separating
an unheated room; or in a draft from a stairwell, door, or window.
• Do not locate in a damp area.
This can lead to corrosion that will shorten thermostat life.
• Do not locate where air circulation is poor, such as:
in a corner or an alcove; or behind an open door.
• Do not install the unit until all construction work and painting has been
completed.
• This thermostat does not require leveling.
You will need #1 Phillips screwdriver (small) and
Drill with 3/16-in. (4.8mm) bit for this installation.
Good
5ft.
(1.5m)

PG 3
PG 4
RESET
MENU PROGRAM
B
G
W
C
H
W
2
R
C
O
B
RH
W
Y
G
A
2 Remove old unit
3 Mount the 8085C
Caution
• Switch electricity to the furnace and air conditioner OFF;
then proceed with the following steps.
• Remove cover from old thermostat. Most are snap-on types and simply pull off.
Some have locking screws on the side or front. These must be
loosened. Note
the letters printed near the terminals.
• Attach labels (enclosed) to each wire for identification.
• Label the wires one at a time. You must have all the wires labeled before you
proceed. With all wires labeled, remove them from the old unit.
• Make sure the wires do not fall back inside the wall.
• Wind them around a pencil to keep them from
falling.
• Loosen all screws on the old thermostat and
remove it from the wall.
• Fill wall opening with non-combustible insulation
to prevent drafts.
Read instructions carefully before removing any wiring from existing thermostat.
Wires must be labeled before they are removed. THERE IS NO STANDARD
COLOR CODE. When removing wires from their terminals, ignore the color of the
wires since these may not follow the standard.
• Separate front from back of unit. Press up on the
catch on bottom of thermostat and swing the body away
from the base, lift up to remove the body from the base.
• Hold the base against the wall, with the wires coming
through the opening below the terminal block.
• Position the base for best appearance. (If you chose to use the optional
wall plate, hold the wall plate against the wall, with the wires coming
through the opening. Then pull the wires through the opening in the base
unit. Position the base unit for best
appearance.)
• Attach the base to the wall with the two
screws provided.
• If you are mounting the base to sheet rock or
if you are using the old mounting holes, use the
plastic anchors provided. Drill a 3/16-in.(4.8mm)
hole for the insert at each screw location, then
mount the base.
Terminal
Block
Wall Plate Thermostat Base

PG 5
GAS
DIFFERENTIA
ELECT
PUMP NORMAL
2
o
3
o
4
o
AA
AA
LOWBATT
LOWBATT
Please be aware of the followng power options
1) The 8085C can run on batteries only. (2AA Alkaline) 
The batteries will last well over 1 year. If the batteries are not replaced the
thermostat will stop working.
2) The 8085C can run on the C wire if available. 24VAC ONLY
As shown in the wiring diagrams, The C wire is the other side of the 24VAC heating
transformer. If the C wire is used, the batteries are then for AC power loss only and
will last much longer. The thermostat will continue working if the batteries die.
6 Install Batteries
The 8085C requires batteries to operate your furnace
and retain its programming in memory.
Switch MODE switch to OFF and
the FAN switch to AUTO.
• Insert 2 AA alkaline batteries according to the polarity
noted in the compartment.
• Press the RESET button to clear transient program
memory. Initially, all LCD segments will go off.
NOTE: Replace the batteries when this LOW battery indicator
appears on the display or once a year. When replacing batteries, you
have approximately 1/2 minute before your custom program is lost.
4 Gas-Electric Selection
5 Heat Pump Switch
7 Power Options
Gas/ Electric
jumper
Heat Pump
Switch
Circuit
Board
Heat Pump
Differentia jumper
Rear view of control unit
PG 6
REFER to the back of the Control Unit:
• If you have Electric Heat or a Heat Pump you must place the Gas/Electric
jumper in the ELECT position (thermostat controls the Fan).
• If you have Gas Heat the Gas/Electric Jumper should be in the GAS position
(furnace controls the Fan ).
NOTE: If you do not have a
Heat Pump, go to step 7.
• If you have a HEAT PUMP
switch the PUMP-NORMAL
switch to the PUMP position.
Reset the unit, the unit display
appear PUMP word.
• Select the desired Temperature
Differential jumper setting. This
determines how much your AUX
heat will come on. Select the
2,3,4, remember reset the unit. 
2 is for comfort or cool climates 
4 is for efficiency or warm
climates.

PG 7
PG 8
Please refer back to these guidelines for safe and secure wire connections.
• Take care not to damage the labels for each wire in handling.
• Strip insulation 3/8 in. (9.5mm) from wire ends.
• Connect labeled wires only to a terminal with corresponding letter.
• Bend the wire slightly, insert the wire under the contact plate and tighten
the screw down onto the wire.
The Wire Label List shows wire
labels used on Ritetemp thermostats.
Please determine what wires you
have and select the correct wiring
diagram to "go to" on pages 8-9.
If you have a HEAT PUMP select a
wiring diagram on pg 9.
If you have a Humidifier select a
diagram on pg9.
Before you Connect Wires
Caution
Do not allow
wires to touch
each other or parts on unit.
Wires must be routed through
the hole in the back plate, below
the terminal block, or they will
hit parts on the cover.
Make sure your wires are labeled. This is necessary to determine which step-by-step
wiring diagram you should use. This may require you to find the 'other end' connection for
each wire on your heating or air conditioning equipment and read the label there. 
If you have a Zoned Heating/Cooling system with multiple thermostats, please refer to our
website at www.ritetemp-thermostats.com for installation notes or call 1-888-515-2585.
8 Wire Connections
What Wires Do You Have?
RH
G
Y
W
C
From Furnace
And AC unit
R
or
RC
G
Y
W
C
From Furnace
And AC unit
RH
Go To Page 13 Go To Page 14
WIRE LABEL LIST
R- Single source power for heat/cool (R connected to
RC and RH using the jumper wire)
RH or R - Heating Power
RC - Cooling Power
W - Heating return
G- Fan return
Y- Compressor return
H - Humidifier (built into the furnace)
W2 - 2nd stage heat in NORMAL, auxiliary heat in PUMP mode.
A- For 3 wire zoned heating systems 
C- AC power for the thermostat if available
O- Damper control (Zoned heating) or heat pump
changeover valve (powered in COOL)
B- Damper control (Zoned heating) or heat pump
changeover valve (powered in HEAT)
NOTE: Do not
connect both O and B on a heat pump. Connect O to
O & tape off B.
X - Tape off X
E - Tape off E
W
RH
R
or
From Furnace
Go To Page 11
C
Go To Page 12
R
or
RH
W
C
From Furnace
G

8 Wire Connections cont
When you have finished connecting the wires, close
cover and attach control unit to wall unit. Hook the
top of the body onto the base, swing the body down,
and snap the body onto the base.
If you do not find the wiring
information for your system try
our webiste for more
information.
9 Check Unit
Follow these procedures to verify you have correctly
installed the unit.
To check HEAT mode:
• Set the mode switch to HEAT. Set the fan switch AUTO.
• Touch the main temperature display then touch the TEMP UP arrow
to raise the set point to 90
o
. Touch HOME. Wait 5 min.
• Verify that heat is blowing from the system.
To check COOL mode:
• Set the mode switch to COOL.
• Touch the main temperature display then
touch the TEMP DOWN arrow to 5
o
below the
room temperature. 
• Touch HOME. Wait 5 min.
• Verify that cool air is blowing from the system.
To check Fan: (If you connected the G wire)
• Switch Mode to OFF during fan test.
• Switch the FAN switch to the ON position. Verify air is blowing from vents. 
• After test, return to Fan switch to AUTO, and Mode to HEAT or COOL
Congratulations, you have successfully installed your unit. Please proceed
to the OPERATING Guide to initialize the new thermostat.
REMEMBER, Mode Switch must be in HEAT or COOL to operate.
PG 9
PG 10
W
G
W2
R
C
From Normal
two stage system
W
RH
H
Humidifier w/ any
Heater
Go To Page 15
B
G
Y
R
C
From heat pump
w/o Aux heat
O
or
Go To Page 16
Go To Page 18
B
G
Y
R
C
From heat pump
with Aux heat
O
or
W or W2
Go To Page 17
RESET
MENU PROGRAM
RESET
MENUPROGRAM
Mode
Switch
Fan
Switch MENU
button
PROGRAM
button

PG 11
PG 12
STEP 1 - Connect the R(or
RH) wire to the RH terminal on
the thermostat.
This connects the Heater
Power to the thermostat.
STEP 2 - Connect the Wwire
to the Wterminal on the
thermostat.
This connects the heater control line to
the thermostat.
Your Heater is now connected to the
thermostat.
STEP 1 - Connect the R(or
RH) wire to the RH terminal
on the thermostat. This
connects to the Heater
Power .
STEP 2 - Connect the Wwire to the W
terminal on the thermostat.
This connects the heater control line to the
thermostat.
STEP 3 - Connect the Gwire to the Gterminal on
the thermostat.
This connects the Fan to the thermostat.
Your system is now connected to the thermostat.
Return To Page 9
Return To Page 9
2 WIRE Heating
(GAS MILLIVOLT or 24vac
NOTE: Wires marked with
the dotted line are optional.
NOTE: Wires marked with
the dotted line are optional.
3 WIRE
W
RH
R
or
From Furnace
C
RH
W
C
From Furnace
G
or R
jumper
wire
FURNACE
HEAT
Thermostat
R W C
HEAT
Power
FURNACE
jumper
wire
Heat
Power Heat
W G RH C
FAN
Thermostat

PG 14
PG 13
From Furnace
and AC unit
G
W
Y
RH
RC
C
R
G
Y
W
C
RH
or
FromFurnace
and AC unit
STEP 1 - Connect the Y wire to
the Yterminal on the thermostat.
This connects to the Cooler
compressor.
STEP 2 - Connect the RH or R
wire to the RH terminal on the
thermostat.
This connects the Heater/Cooler
Power.
STEP 3 - Connect the Wwire to the W
terminal on the thermostat.
This connects to the heater control line.
STEP 4 - Connect the G wire to the Gterminal on the Thermostat.
This connects to the Fan.
Your HVAC system is now connected to the thermostat.
STEP 1 - Remove the Jumper wire.
STEP 2 - Connect the Y
wire to the Yterminal on the
thermostat. This connects to
the Cooler compressor.
STEP 3 - Connect the RH wire to the RH
terminal on the thermostat. This connects to the
Heater Power .
STEP 4 - Connect the RC wire to the RC terminal
on the thermostat. This connects to the Cooling
Power .
STEP 5 - Connect the Wwire to the Wterminal on the thermostat.
This connects to the heater control line.
STEP 6 - Connect the G wire to the Gterminal on the Thermostat.
This connects to the Fan.
Your HVAC system is now connected to the thermostat.
Return To Page 9
Return To Page 9
5 WIRE NON_HEAT PUMP
4 WIRE NON_HEAT PUMP
NOTE: Wires marked with
the dotted line are optional.
NOTE: Wires marked with
the dotted line are optional.
HVAC SYSTEM
jumper
wire
Heat
Power Heat
WG RH
C
FAN
Y
Cool
Comp
Thermostat
HVAC SYSTEM
Remove
jumper
wire
HEAT
Power
Heat
WG RHRC
C
FAN
Y
Cool
Comp
COOL
Power
Thermostat

PG 16
PG 15
STEP 1 - Connect the G wire to
the Gterminal on the thermostat.
This connects the Fan.
STEP 2 - Add a jumper wire
between Wand Y.
STEP 3 - Connect the Ywire to
the Y terminal on the thermostat.
This connects the Compressor.
STEP 4 - Connect the O or B wire
to the O or B terminal on the
thermostat. (If you have both Oand B contact
Ritetemp or your local HVAC contractor for further
help) This connects the change over valve.
STEP 5 - Connect the R wire to the RC terminal on the Thermostat.
This connects to the 24vac power.
Your HVAC system is now connected to the thermostat.
Return To Page 9
HEAT PUMP
w/o Auxillary Heat
NOTE: Wires marked with the dotted line are optional.
From Furnace
and AC unit
R
G
Y
C
O
or
B
O or B
Single Stage HEAT PUMP
Change
Over
G
O or B
R
C
FAN
Y
Comp
24VAC
Power
jumper
wire
jumper
wire
Thermostat
STEP 1 - Connect the G wire to
the Gterminal on the thermostat.
This connects the Fan.
STEP 2 - Connect the
between W wire to W. This
connects the 1st stage heat.
STEP 3 - Connect the between
W2 wire to W2. This connects the
2nd stage heat.
STEP 4 - Connect the R wire to the RH terminal on
the Thermostat. This connects to the 24vac power.
Your HVAC system is now connected to the thermostat.
(If the system also has AC, connect it per instructions for RC and Y on pg 14)
Return To Page 9
NORMAL 2 Stage 
Heat System
NOTE: Wires marked with the dotted line are optional.
Two Stage Heat System
G
RW2
C
FAN
W
Two Stage
Furnace
jumper
wire
Thermostat
W
G
W2
R
C
From Normal
two stage system

PG 18
PG 17
STEP 1 - Connect the G wire to
the Gterminal on the thermostat.
This connects the Fan.
STEP 2 - Add a jumper wire
between Wand Y.
STEP 3 - Connect the Ywire to
the Y terminal on the thermostat.
This connects the Compressor.
STEP 4 - Connect the O or B wire to the
O or B terminal on the thermostat. (If you have both O
and B wires, use the Oand tape off the B).
This connects the change over valve.
STEP 5 - Connect the R wire to the RC terminal on
the Thermostat. This connects to the 24vac power.
STEP 6 - Connect W or W2 to W2 on the thermostat. This connects the AUX heat.
Your HVAC system is now connected to the thermostat.
Return To Page 9
HEAT PUMP
with Auxillary Heat
NOTE: Wires marked with the dotted line are optional.
STEP 1 - Connect the H wire to the Hterminal on
the thermostat.
This connects the Humidifier.
STEP 2 - Connect the Wwire to the W terminal on the
thermostat. This connects the Heat control line.
STEP 3 - Connect the Rwire to the RH terminal on
the thermostat.
This connects the Heater Power.
Your Humidifier and heater are now connected to the thermostat.
Return To Page 9
NOTE: Wires marked with the dotted line are optional.
O or B
(not both)
HEAT PUMP
Change
Over
AUX
Heat
G
O or B
R
C
FAN
Y
Comp
24VAC
Power
jumper
wire
jumper
wire
Thermostat
Humidifier
H R W
C
24VAC
Power
jumper
wire
Thermostat
W
RH
H
ExternalHumidifier
w/ any Heater
B
G
Y
R
C
From heat pump
with Aux heat
O
or
W
or
W2