271015-UUM-A-0407

4 RED FLASHES: This indicates that a primary or auxiliary limit switch has opened its normally closed contacts. With this fault code the control will operate the supply air blower and inducer. This condition may be caused by: dirty filter, improperly sized duct system, incorrect blower speed setting, incorrect firing rate or faulty blower motor.

5 RED FLASHES: This fault is indicated if the normally closed contacts in the rollout switch opens. The rollout control is manually reset. If it has opened, check for proper combustion air, proper inducer operation, and primary heat exchanger failure or burner problem. Be sure to reset the switch after correcting the failure condition.

6 RED FLASHES: This indicates that after the unit was operating, the pressure switch opened 4 times during the call for heat. If the main blower is in a “Delay on” mode it will complete it, and any subsequent delay off period. The furnace will lock out for one hour and then restart.

7 RED FLASHES: This fault code indicates that the flame could not be established. This no-light condition occurred 3 times (2 retries) during the call for heat before locking out. Low gas pressure, faulty gas valve, faulty hot surface ignitor or burner problem may cause this. The furnace will lock out for one hour and then restart.

8 RED FLASHES: This fault is indicated if the flame is lost 5 times (4 recycles) during the heating cycle. This could be caused by low gas pressure or faulty gas valve. The furnace will lock out for one hour and then restart.

9 RED FLASHES: Indicates reversed line voltage polarity or grounding problem. Both heating and cooling operations will be affected. Check polarity at furnace and branch. Check furnace grounding. Check that flame probe is not shorted to chassis.

10 RED FLASHES: Gas valve energized with no call for heat. Check gas valve and gas valve wiring.

11 RED FLASHES: This indicates that a primary or auxiliary limit switch has opened its normally-closed contacts and has remained open for more than five minutes. This condition is usually caused by a failed blower motor or blower wheel.

12 RED FLASHES: This code indicates an open igniter circuit, which could be caused by a disconnected or loose wire or by a cracked or bro- ken igniter.

STEADY ON RED: Control failure. Replace control board.

60-MINUTE AUTOMATIC RESET FROM LOCKOUT: This control includes a “watchdog” type circuit that will reset from a lockout condition after 60 minutes. Operational faults 6,7,8 will be reset. This provides protection to an unoccupied structure if a temporary condition exists causing a furnace malfunction. An example would be a low incoming gas supply pressure preventing unit operation. When the gas pressure is restored, at some point the “watchdog” would restart the unit and pro- vide heat for the house.

NOTE: If a flame is detected the control flashes the LED for 1/8 of a second and then enters a flame stabilization period.

IGNITION CONTROL

Normal flame sense current is approximately

3.7 microamps DC (µa)

Low flame signal warning starts at 1.5 microamps.

Low flame signal control lockout point is

0.1 microamps DC (µa)

DIAGNOSTIC FAULT CODE STORAGE AND RETRIEVAL

The control in this furnace is equipped with memory that will store up to five error codes to allow a service technician to diagnose problems more easily. This memory will be retained even if power to the furnace is lost. This feature should only be used by a qualified service tech- nician.

The control stores up to five separate error codes. If more than five error codes have occurred since the last reset, only the five most recent will be retained. The furnace control board has a button, labeled "LAST ERROR" that is used to retrieve error codes. This function will only work if there are no active thermostat signals. So any call for heating, cooling or continuous fan must be terminated before attempting to retrieve error codes.

To retrieve the error codes, push the LAST ERROR button. The LED on the control will then flash the error codes that are in memory, starting with the most recent. There will be a two-second pause between each flash code. After the error codes have all been displayed, the LED will resume the normal slow green flash after a five second pause. To repeat the series of error codes, push the button again.

If there are no error codes in memory, the LED will flash two green flashes. To clear the memory, push the LAST ERROR button and hold it for more than five seconds. The LED will flash three green flashes when the memory has been cleared, then will resume the normal slow green flash after a five-second pause.

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Unitary Products Group

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York LC8V*DH, PV8*DH, FC8V*DH, FL8V*DH, LL8V*DH service manual Diagnostic Fault Code Storage and Retrieval, Ignition Control
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LL8V*DH, LC8V*DH, FL8V*DH, FC8V*DH, PV8*DH specifications

The York FL8V*DH, LC8V*DH, PV8*DH, LL8V*DH, and FC8V*DH series represent a range of advanced heating and cooling solutions tailored to meet the needs of both residential and commercial applications. These units are engineered with cutting-edge technologies that enhance energy efficiency, performance, and user comfort, making them a top choice for HVAC needs.

One of the standout features of these systems is their high-efficiency design, which often exceeds industry standards. The FL8V*DH, for example, boasts an impressive SEER (Seasonal Energy Efficiency Ratio) rating, allowing users to save on energy costs while ensuring optimal heating and cooling comfort. The innovative design minimizes energy consumption without compromising performance, which is critical in today’s eco-conscious market.

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The technology behind these models extends to their variable-speed blower motors, which provide precise airflow and temperature control. This flexibility allows adjustments based on real-time demand, enhancing comfort and reducing energy usage. The use of smart thermostats with these systems enables users to program schedules, monitor usage, and optimize settings remotely, further improving efficiency.

In terms of durability and reliability, the York series is built from high-quality materials designed to withstand the test of time. Robust construction minimizes maintenance needs, resulting in lower long-term ownership costs. Additionally, many units feature quiet operation technologies, ensuring minimal noise disturbance, which is particularly important in residential settings.

Moreover, installation and servicing of the York FL8V*DH, LC8V*DH, PV8*DH, LL8V*DH, and FC8V*DH systems are made simpler through their user-friendly designs. Easy access points for maintenance staff help to reduce downtime and enhance system longevity.

Overall, the York FL8V*DH, LC8V*DH, PV8*DH, LL8V*DH, and FC8V*DH units stand out due to their efficiency, innovative technology, durability, and user-friendly design, marking them as exceptional choices in the HVAC market. These systems not only provide comfort but also align with energy-saving initiatives, making them a wise investment for the future.
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