background image

271042-UUM-A-0407

8

Unitary Products Group

FURNACE CONTROL DIAGNOSTICS

The furnace has built-in, self-diagnostic capability. If a system problem
occurs, a blinking LED shows a fault code. The LED can flash red,
green or amber to indicate various conditions. It is located behind a
clear view port in the blower compartment door.

The control continuously monitors its own operation and the operation
of the system. If a failure occurs, the LED will indicate the failure code. 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.

Flash sequence codes 1 through 10 are as follows: LED will turn “on”
for 1/4 second and “off” for 1/4 second. This pattern will be repeated the
number of times equal to the code. For example, six “on” flashes equals
a number 6 fault code. All flash code sequences are broken by a 2 sec-
ond “off” period.

SLOW GREEN FLASH: 

Normal operation.

SLOW AMBER FLASH:

 Normal operation with call for heat.

RAPID RED FLASH:

 Twinning error, incorrect 24V phasing. Check

twinning wiring.

RAPID AMBER FLASH:

 Flame sense current is below 1.5 microamps.

Check and clean flame sensor. Check for proper gas flow.

4

 

AMBER FLASHES: 

The control board is recieving a “Y” signal from

the thermostat without a “G” signal, indicating improper thermostat wir-
ing.

1 RED FLASH:

 This indicates that flame was sensed when there was

not a call for heat. With this fault code the control will turn on both the
inducer motor and supply air blower. A gas valve that leaks through or
is slow closing would typically cause this fault.

2 RED FLASHES:

 This indicates that the normally open pressure

switch contacts are stuck in the closed position. The control confirms
these contacts are open at the beginning of each heat cycle. This would
indicate a faulty pressure switch or miswiring.

3 RED FLASHES:

 This indicates the normally open pressure switch

contact did not close after the inducer was energized. This could be
caused by a number of problems: faulty inducer, blocked vent pipe, bro-
ken pressure switch hose or faulty pressure switch.

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.

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.

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)

Содержание FC9V DH Series

Страница 1: ...deemed necessary FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in serious injury death or property damage Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance WHAT TO DO IF YOU SMELL GAS Do not try to light any appliance Do not touch any electrical switch do not use any phone including cell phone in your...

Страница 2: ...nace casing making sure the physical support is sound without sagging cracks or gaps Examine the furnace base making sure it is physically sound without cracks gaps or sagging and has a good seal 5 Examine the furnace casing for obvious signs of deterioration 6 Examine the burner flames to make sure they are in good adjust ment Refer to the pictorial sketch shown in Figure 2 as a compari son to th...

Страница 3: ...ructions 1 STOP Read the safety information above 2 Set the thermostat to the lowest setting 3 Turn off all electric power to the appliance 4 Remove burner door 5 Move gas control switch to the OFF position Do not force 6 Wait five 5 minutes to clear out any gas If you then smell gas STOP Follow B in the safety information above If you don t smell gas go to next step 7 Move gas control switch to t...

Страница 4: ...hed to the cas ing of the furnace or placed in the return air duct You can gain access to the filter by pulling on the door or unscrewing the retaining screw then slide the filter s out of its channel Replace throw away filter s with the same size new filter s Throw away filter s may be replaced with cleanable filter s at this time Cleanable filter s may be cleaned as described in the manufacturer...

Страница 5: ...nd the rear heat exchanger tubes Then vacuum loose the scale and dirt from each tube 9 Replace all components in reverse order Reconnect all wiring 10 Restore electrical power and gas supply to the furnace 11 Check furnace operation Cleaning the Secondary Heat Exchanger 1 Follow steps 1 7 under cleaning the Heat Exchanger 2 Remove the vent piping from the vent blower housing Disconnect the drain l...

Страница 6: ...The thermostat opens the R to Y and R to G circuits The Outdoor Unit is de energized The 60 second Blower Off Delay timing circuit is initiated After 60 seconds the Cool and EAC relays are de energized CONTROL BOARD Variable speed motors will adjust the motor speed in order to maintain the indoor fan CFM The control board is used to control the blower speed thus the CFM when the unit is operating ...

Страница 7: ... a higher speed will take 30 seconds and any ramp down to a lower speed or off will take 60 seconds Tap D is the normal profile best suited for most of the country where neither excessive humidity nor extremely dry conditions are the norm On a call for cooling the motor will ramp up to 63 of full capacity and will stay there for 90 seconds then will ramp up to full capacity At the end of the cooli...

Страница 8: ...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 re...

Страница 9: ...ucts Group 9 SECTION III REPLACEMENT PARTS LIST 70 34 57 2 59 61 54 5 26 68 8 52 62 12 7 25 27 13A 26 51 25 71 1 15 50 51 18 17 20 45 68 47 49 29 13 5 8 35 52 4 2 41 42 43 46 44 16 14 3 10 13 34 9 6 19 22 28 29 32 31 48 53 58 62 49 ...

Страница 10: ... 39 MISCELLANEOUS 40 41 RESTRICTOR COMBUSTION BLWR 42 GASKET COMBUSTION BLOWER 43 GASKET CONDENSATE PAN 44 GASKET CONDENSING COIL 45 GASKET GAS CONTROLS 46 GASKET UPPER COND PAN 2 Req d 47 GASKET COMBUSTION AIR TRANSITION 48 GROMMET MANIFOLD SEAL 49 PLUG WINDOW CLEAR 1 5 50 GROMMET MOTOR MOUNT 3 Req d 51 FERRULE MOTOR MOUNT 3 Req d 52 PAN CONDENSATE 53 ORIFICE BURNER Natural 45 54 TRAP CONDENSATE ...

Страница 11: ...ENT TERMINATION KIT 2 ALL MODELS 1CB0317 COMBUSTIBLE FLOOR BASE 17 1 2 CABINET 1CB0321 21 CABINET 1CB0324 24 1 2 CABINET 1TK0917 COIL TRANSITION KIT 17 1 2 CABINET 1TK0921 21 CABINET 1TK0924 24 1 2 CABINET REPLACEMENT PART CONTACT INFORMATION This is a generic parts list To request a complete parts list refer to the contact information below Visit our website at www source1parts com for the follow...

Страница 12: ...271042 UUM A 0407 12 Unitary Products Group SECTION IV WIRING DIAGRAM FIGURE 8 Wiring Diagram ...

Страница 13: ...271042 UUM A 0407 Unitary Products Group 13 NOTES ...

Страница 14: ...271042 UUM A 0407 14 Unitary Products Group NOTES ...

Страница 15: ...271042 UUM A 0407 Unitary Products Group 15 NOTES ...

Страница 16: ...nly to products installed in the United States and Canada EXCLUSIONS This warranty does not cover any 1 Shipping labor or material charges 2 Damages resulting from transportation installation or servicing 3 Damages resulting from accident abuse fire flood alteration or acts of God tampering altering defacing or removing the product serial number will serve to void this warranty 4 Damages resulting...

Отзывы: