White Rodgers PS9 Up, FL9s UP, FC9s Up UUM-A-0407, Diagnostic Fault Code Storage And Retrieval

269434-UUM-A-0407

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.

Thermostat Calling for Heat

(Seconds) 0 2 17 22 52

Fan on Delay 30 Seconds

ON

THERMOSTAT

OFF

ON

INDUCER

OFF

ON

Thermostat Satisfied

0

OFF
15 Sec.	OFF
Post
Purge

IGNITOR OFF

MAIN VALVE

OFF

HUMIDIFIER

OFF

ELECTRONIC

AIR CLEANER

OFF

CIRCULATING

BLOWER OFF

OFF

ON

ON

OFF

ON

OFF

ON

OFF

OFF

OFF

OFF

OFF

60, 90, 120, 180 SEC. OFF Selectable Fan Off Delay

FIGURE 7: Furnace Control Event Schedule

Unitary Products Group 7