SYSTEM LOCKOUT AND

DIAGNOSTIC FEATURES

SYSTEM LOCKOUT FEATURES

When system lockout occurs, the gas valve is de-energized, the circulator blower is energized at heat speed, and, if flame is sensed, the inducer blower is energized. The diagnostic indica- tor light will flash or glow continuously to indicate system status.

(System lockout will never override any precautionary features.)

To reset the control after system lockout, do one of the following:

1.Interrupt the call for heat or cool at the thermostat for at least one second but less than 20 seconds (if flame is sensed with the gas valve de-energized, interrupting the call for heat at the thermostat will not reset the control).

2.Interrupt the 24 VAC power at the control for at least one second. You may also need to reset the flame rollout sensor switch.

3.After one hour in lockout, the control will automatically reset itself.

DIAGNOSTIC FEATURES

The 50A55 control continuously monitors its own operation and the operation of the system. The LED light on the control will flash slowly (one flash per second) if there are no failures and no call for heat. If there is a call for heat, the LED will flash quickly (one flash per half-second). If a failure occurs, the LED will indicate a failure code as shown below. If the failure is internal to the control, the light will stay on continuously. In this case, the entire control should be replaced, as the control is not field-repairable. If the LED is continuously off, there may be no power to the control; the fuse on the control may be open; or there may be a failure in the control.

If the sensed failure is in the system (external to the control), the LED will flash in the following flash-pause sequences to indicate failure status (each flash will last approximately 0.25 seconds, and each pause will last approximately 2 seconds).

2 flashes, then pause

System lockout (no flame)

3 flashes, then pause

Pressure switch problem

4 flashes, then pause

Thermal protection device open

5 flashes, then pause

Flame sensed with gas valve off

6 flashes, then pause

115 Volt AC power reversed/im-

 

proper ground

7 flashes, then pause

Gas valve circuit error

8 flashes, then pause

Low flame sense signal

The LED will also flash once at power-up.

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White Rodgers 50A55-438 installation instructions System Lockout Diagnostic Features, System Lockout Features
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50A55-438 specifications

The White Rodgers 50A55-438 is a highly versatile and efficient thermostat widely recognized for its reliability and advanced features. Designed with both functionality and user-friendliness in mind, this device serves as an excellent solution for managing heating and cooling systems in residential and commercial applications.

One of the standout features of the 50A55-438 is its compatibility with a wide range of HVAC systems. It supports single-stage and multi-stage heating and cooling units, allowing users to integrate it seamlessly into various setups. This versatility makes it suitable for diverse environments, from single-family homes to larger commercial spaces.

The thermostat is equipped with a user-friendly interface, complete with a large, easy-to-read display that simplifies temperature adjustments and system monitoring. The illuminated screen enhances visibility, allowing users to operate the device even in low-light conditions. Its intuitive menu system guides users through programming options, making it accessible for individuals without extensive technical knowledge.

In terms of energy management, the White Rodgers 50A55-438 utilizes advanced algorithms that promote energy efficiency. The programmable capabilities enable users to set specific heating and cooling schedules, optimizing comfort while minimizing energy consumption. This feature is particularly beneficial for those looking to reduce utility costs while maintaining a pleasant indoor climate.

The thermostat also includes features such as a temperature lock, which prevents unauthorized adjustments, making it an ideal choice for rental properties or commercial sites where temperature control is critical. Additionally, it offers an automatic changeover function, allowing the device to switch between heating and cooling modes based on the ambient temperature, thus ensuring consistent comfort year-round.

The White Rodgers 50A55-438 is built to last, featuring robust construction designed to withstand the rigors of daily use. It operates quietly, contributing to a serene environment in homes and workplaces. Furthermore, installation is straightforward, as the thermostat is designed to fit standard wall plates and connections, enabling a hassle-free setup process.

In summary, the White Rodgers 50A55-438 stands out as a top choice for those seeking an advanced, efficient, and easy-to-use thermostat. Its compatibility with various HVAC systems, programmable features, energy-saving capabilities, and robust design make it an excellent investment for effective climate control. Whether for residential or commercial use, this thermostat meets the demands of modern temperature regulation with precision and reliability.
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