White Rodgers 50A66-743 installation instructions Troubleshooting, Diagnostic Table

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TROUBLESHOOTING

DIAGNOSTIC TABLE

DS 1 (Red)

DS 2 (Green)

Error/Condition

Comments/Troubleshooting

 

 

 

 

Simultaneous

Simultaneous

Normal operation

No fault

slow flash

slow flash

 

 

 

 

 

 

Simultaneous

Simultaneous

Normal operation with

Normal operation

fast flash

fast flash

call for heat

 

 

 

 

 

Slow flash

On

Open limit switch

Verify continuity through rollout switch circuit

 

 

 

 

Off

Slow flash

Pressure switch stuck

Pressure switch stuck closed. Check switch function, verify

 

 

closed/open

inducer is turning off.

 

 

 

Pressure switch stuck open. Check pressure switch function

 

 

 

and tubing. Verify inducer is turning on and pulling sufficient

 

 

 

vacuum to engage switch.

 

 

 

 

Alternate

Alternate slow

External lockout

Failure to sense flame is often caused by carbon deposits on

slow flash

flash

(retries)

the flame sensor, a disconnected or shorted flame sensor

 

 

 

lead or a poorly grounded furnace. Carbon deposits can be

 

 

 

cleaned with emery cloth. Verify sensor is not contacting the

 

 

 

burner and is located in a good position to sense flame.

 

 

 

Ignitor must be positioned to light the gas immediately when

 

 

 

the valve opens. If the ignitor has been replaced, verify hot

 

 

 

spot position has not changed.

 

 

 

Check sensor lead for shorting and verify furnace is

 

 

 

grounded properly.

 

 

 

 

Slow flash

Off

Flame sensed with gas

Verify the gas is operating and shutting down properly. Flame

 

 

valve de-energized

in burner assembly should extinguish promptly at the end of

 

 

 

the cycle. Check orifices and gas pressure.

 

 

 

 

On

Slow flash

Open rollout switch

Verify continuity through rollout switch circuit.

 

 

 

 

On

On

Module – internal fault

Module contacts for gas valve not operating or processor

 

 

condition

fault. Reset control, if condition persists, replace module.

 

 

 

 

Slow flash

Fast flash

Low flame sense

Low flame sense current is often caused by carbon deposits

 

 

current

on the flame sensor, a poorly grounded furnace or a mis-

 

 

 

aligned flame sense probe. Carbon deposits can be cleaned

 

 

 

with emery cloth.

 

 

 

Check or improve furnace and module ground. Verify sensor

 

 

 

is located in or very near flame as specified by the appliance

 

 

 

manufacturer.

 

 

 

 

Fast flash

Slow flash

Grounding or

Verify the control and furnace are properly grounded. Check

 

 

reversed polarity

and reverse polarity (primary) if incorrect.

 

 

 

 

Alternate fast

Alternate fast

Module ignitor

Fault code indicates the module ignitor contacts are not

flash

flash

contact failure

functioning properly. Replace module.

 

 

 

 

Homeowner Help Line: 1-800-284-2925

White-Rodgers is a business of Emerson Electric Co.

The Emerson logo is a trademark and service mark of Emerson Electric Co.

www.white-rodgers.com www.emersonclimate.com

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Contents Installation Instructions PrecautionsContents DescriptionSpecifications Electrical Ratings @ 77F 25C Operating Temperature RangeTiming Specifications Humidity RangeAny orientation is acceptable InstallationMounting and Wiring Wiring Typical System Wiring DiagramTypical System Wiring Table System ComponentTerminal ConnectionOperation Option Switches Heat ModeCool Mode Manual FAN on ModeDiagnostic Features System Lockout and Diagnostic FeaturesSystem Lockout Features Troubleshooting Diagnostic Table

50A66-743 specifications

The White Rodgers 50A66-743 is a state-of-the-art heating and cooling thermostat designed for maximum comfort and efficiency in residential environments. This versatile device is known for its reliability and user-friendly features, making it a popular choice among homeowners and HVAC professionals alike.

One of the key features of the 50A66-743 thermostat is its programmable functionality. Users can easily set temperature schedules for different times of the day, ensuring optimal energy consumption while maintaining a comfortable home environment. With the option to program up to four different time periods per day, this thermostat allows for customizable comfort tailored to the homeowner's lifestyle.

The 50A66-743 employs advanced technology to facilitate precise temperature control. Its microprocessor-based design ensures accurate readings and smooth operation, allowing the system to maintain the set temperature with minimal fluctuation. This not only enhances comfort but also promotes energy efficiency, which can result in reduced utility bills.

Another notable characteristic of the White Rodgers 50A66-743 is its compatibility with various heating and cooling systems. It can easily integrate with single-stage and multi-stage systems, including gas, oil, and electric furnaces, as well as heat pumps. This versatility makes it an ideal choice for diverse HVAC applications.

User convenience is a top priority with this model, and it is equipped with a clear, easily readable display that provides real-time temperature readings. The backlit screen enhances visibility, making it easy for users to check the status of their heating or cooling systems, even in low-light conditions.

Additionally, the 50A66-743 features a simple interface with intuitive buttons that allow for quick adjustments to temperature settings. This straightforward design minimizes the learning curve for new users, making it accessible for families of all ages.

The thermostat also includes a filter change reminder, which helps homeowners stay on top of maintenance tasks, ensuring optimal system performance. Regular filter changes are crucial for maintaining air quality and efficiency, and this alert serves as a helpful nudge to keep homeowners proactive about their HVAC systems.

In summary, the White Rodgers 50A66-743 thermostat combines advanced technology, user-friendly features, and compatibility with various HVAC systems, making it an excellent choice for those seeking comfort and efficiency in their homes. Its programmable functionality, precise temperature control, and convenient design ensure that users can easily manage their home’s climate while saving on energy costs.