Aprilaire 8334 To Test Thermostat, Operation, Changing Fahrenheit F to Celsius C, Wiring Diagrams

To Test Thermostat

WARNING: DO NOT SHORT (JUMPER) ACROSS TERMINALS OF GAS VALVE OR SYSTEM CONTROL TO TEST OPERATION. THIS WILL DAMAGE THE THERMOSTAT AND VOID YOUR WARRANTY.

CAUTION: Do not switch system to cool if the temperature is below 50°F (10°C). This can damage the air conditioning system and cause personal injury.

Operation

Setting or Changing the Setpoint Temperature

1. Press either the >or>button.

The display will show the current

temperature setpoint. > >

Changing Fahrenheit (F) to Celsius (C)

The thermostat is preset to display the temperature in degrees Fahrenheit. You may change the display readout to Celsius if desired.

1.Move the manual switch marked “F” (Fahrenheit) and “C” (Celsius) located at the top center of the circuit board to the desired setting.

2.Press RESET button located lust below the LCD display to register the change.

Wiring Diagrams

The following is just a sample of the most common types of HVAC systems. Refer to your systems installation manual for wiring information.

HEAT/COOL	HEAT ONLY
4-WIRE	3-WIRE
SINGLE TRANSFORMER	SINGLE TRANSFORMER

Limited Warranty

Your Research Products Corporation Aprilaire® Thermostat unit is expressly warranted for two (2) years from date of installation to be free from defects in materials and workmanship.

Research Products Corporation’s exclusive obligation under this warranty shall be to supply, without charge, a replacement for any thermostat which is found to be defective within a two (2) year period and which is returned,

1. Place the COOL-OFF-HEAT switch	COOL OFF HEAT
into the COOL position
2. Press the>button until the
temperature setting is at least
3 degrees below the room temperature.
The air conditioning system should
turn on within a few seconds.

> > COOL OFF HEAT FAN: AUTO - ON

2. Press either the >or> button to adjust the temperature setting either up or down.

The display will change to show the temperature in your desired temperature scale. To return the thermostat to its original setting, repeat steps 1 and 2 above.

TROUBLESHOOTING

			Factory-Installed
			jumper
				RH	T
Transformer					H
					E
	Hot			RC	R
120 VAC		24 VAC
			Heating	W	M
			Control
					O
			Cooling	Y	S
			Control		T
					A
			Fan	G	T
			Control

Factory- Installed

jumper

		RH	T
Transformer			H
Hot		RC	E
120 VAC	24 VAC		R
	Heating	W	M
	Control
			O
		Y	S
			T
	Fan	G	A
	Control		T

together with the date of installation, no later than thirty (30) days after said two (2) year period by you to either your original supplier or to Research Products Corporation, Madison, Wisconsin 53701.

THIS WARRANTY SHALL NOT OBLIGATE RESEARCH PRODUCTS CORPO- RATION FOR ANY LABOR COSTS AND SHALL NOT APPLY TO DEFECTS IN WORKMANSHIP OR MATERIALS FURNISHED BY YOUR INSTALLER AS CONTRASTED TO DEFECTS IN THE THERMOSTAT ITSELF.

NOTE: When in the COOL mode (or HEAT and COOL for single stage heat pumps), once the thermostat turns off, a built in 5-minute delay prevents the system from turning on again. This protects the compressor. No additional time delay relay is required.

The display will return to the room temperature display five seconds after the last input and the new setpoint will be saved.

Symptom	Remedy
Thermostat does not turn	Check Wiring
on system	(see INSTALLATION).
	Check fuse. Replace with 2 amp

HEAT ONLY
2-WIRE	COOL ONLY
SINGLE TRANSFORMER	3-WIRE
	SINGLE TRANSFORMER

NOTE: Remove factory installed jumper

IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PAR- TICULAR PURPOSE SHALL BE LIMITED IN DURATION TO THE AFORESAID TWO YEAR PERIOD. RESEARCH PRODUCTS CORPORATION’S LIABILITY FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES, OTHER THAN DAMAGES

fuse if fuse has opened.

RH

T

3.Put the COOL-OFF-HEAT switch into the OFF position. The air conditioning system should turn off.

4.Put the COOL-OFF-HEAT switch into the HEAT position.

COOL OFF HEAT

COOL OFF HEAT

Thermostat turns on and	Increase Temperature Differential
off too frequently.	(see DIFFERENTIAL).
Display is blank, flashing	Replace batteries.
or constant “LO BAT”.

Transformer

Hot
120 VAC	24 VAC

Heating Control

H

RC E

R

WM O

YS T A

GT

	Transformer			RH	H
					E
	Hot			RC
120 VAC		24 VAC			R
				W	M
					O
			Cooling	Y	S
			Control
					T
					A
			Fan	G
			Control		T

FOR PERSONAL INJURIES, RESULTING FROM ANY BREACH OF THE AFORE- SAID IMPLIED WARRANTIES OR THE ABOVE LIMITED WARRANTY IS EXPRESSLY EXCLUDED. THIS LIMITED WARRANTY IS VOID IF DEFECT(S) RESULT FROM FAILURE TO HAVE THIS THERMOSTAT INSTALLED BY A QUALIFIED HEATING AND AIR CONDITIONING CONTRACTOR. IF THE

5. Press the> button until the temperature setting is at least

3 degrees above room temperature. The heating system should turn on. The fan may not turn on immediately, depending upon the fan delay built into the furnace.

6. Put the COOL-OFF-HEAT switch

into the OFF position. The heating

system should turn off. The fan may

continue to run for a short period

of time.

7. Put the FAN: AUTO-ON switch to

COOL OFF HEAT

FAN: AUTO - ON

Changing Temperature Differential

IMPORTANT: The temperature differential is factory set at 1 (.5°). This means that whenever the room temperature changes by one half of a degree from the temperature setting, the system will turn on. If the system turns on too often, increase the temperature differential.

1. Press both >and> buttons at the same time and hold for one

second. > >

> > COOL OFF HEAT FAN: AUTO - ON

2. Press either the >or> button to adjust the temperature

System fan does not	Move fan option switch to either
operate properly.	gas or electric, to match system
	(see INSTALLATION).
Thermostat does not display	Check “F” Fahrenheit/”C” Celsius
proper room temperature.	switch located at top center of
	circuit board for proper position.
	If a new selection is made, press
	“RESET” button located directly
	below LCD display.

HEAT/COOL

5-WIRE

TWO TRANSFORMER

	(HEATING)
	Transformer
					T
	Hot			RH
120 VAC		24 VAC			H
				RC	E
					R
			Heating	W	M
			Control		O
			Cooling	Y	S
	Hot		Control		T
120 VAC		24 VAC			A
			Fan	G
					T
			Control

(COOLING) Transformer

NOTE: Cut center of factory installed jumper and bend back

NOTE: Both transformers must be in phase.

LIMITED WARRANTY IS VOID DUE TO FAILURE TO USE A QUALIFIED CONTRACTOR, ALL DISCLAIMERS OF IMPLIED WARRANTIES SHALL BE EFFECTIVE UPON INSTALLATION.

Some states do not allow limitations on how long an implied warranty lasts or the exclusion or limitation of incidental or consequential damages, so the above exclusion or limitations may not apply to you.

This warranty gives you specific legal rights and you may also have other rights which vary from state to state.

the ON position. The blower fan

should turn on.

differential up or down.

The display will show:

If problems with thermostat cannot be solved, call:

Technical Support: 608-257-8801

HEAT PUMP WITH	HEAT PUMP WITH
COOL ACTIVE	HEAT ACTIVE
REVERSING VALVE	REVERSING VALVE

8. Put the FAN: AUTO-ON switch to

the AUTO position. The blower fan

should turn off.

FAN: AUTO - ON

Differential Setting Degrees

11°F/.5°C

22°F/1.0°C

33°F/1.5°C

Monday-Friday 7:45 am-5:00 pm CST

Transformer

Hot

120 VAC 24 VAC

Fan

Relay

Compressor

Contactor

Reversing

Valve

	Pre-Installed jumper
RH	T
		Transformer
RC	H	Hot
	E
		120 VAC	24 VAC
W	R
	M		Fan
G	O
			Relay
	S		Compressor
Y	T
			Contactor

A

OT

B	Reversing
	Valve

Pre-Installed jumper

RH T

H

RC

E

R

W

M

GO

S

YT

A

OT

B

The display will return to the room temperature five seconds after the last input.

NOTE: Installer must place jumper	NOTE: Installer must place jumper
between “W” and “Y” terminals.	between “W” and “Y” terminals.

P.O. BOX 1467 • MADISON, WI 53701-1467

Products For Better Indoor Air Quality™

B2202515 REV. 12/00

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