I have a York Gas Furnace model GY9S1000C20DH11G that has a Fault Code 3. How do you reset the limit switch?Thanks
Make : York
Model : GY9S100C20DH11G
At first I had 11 red flashes, so I unplugged the unit and started looking for the limit switch. I decided to plug it back in and it worked for about 10 minutes, now I have 4 red flashes
SLOW GREEN FLASH: Normal operation.SLOW AMBER FLASH: Normal operation with call for heat.RAPID RED FLASH: Twinning error, incorrect 24V phasing. Checktwinning 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 fromthe thermostat without a “G” signal, indicating improper thermostat wiring.1 RED FLASH: This indicates that flame was sensed when there wasnot a call for heat. With this fault code the control will turn on both theinducer motor and supply air blower. A gas valve that leaks through oris slow closing would typically cause this fault.2 RED FLASHES: This indicates that the normally open pressureswitch contacts are stuck in the closed position. The control confirmsthese contacts are open at the beginning of each heat cycle. This wouldindicate a faulty pressure switch or miswiring.3 RED FLASHES: This indicates the normally open pressure switchcontact did not close after the inducer was energized. This could becaused by a number of problems: faulty inducer, blocked vent pipe, brokenpressure switch hose or faulty pressure switch.4 RED FLASHES: This indicates that a primary or auxiliary limit switchhas opened its normally closed contacts. With this fault code the controlwill operate the supply air blower and inducer. This condition may becaused by: dirty filter, improperly sized duct system, incorrect blowerspeed setting, incorrect firing rate or faulty blower motor.5 RED FLASHES: This fault is indicated if the normally closed contactsin the rollout switch opens. The rollout control is manually reset. If it hasopened, check for proper combustion air, proper inducer operation, andprimary heat exchanger failure or burner problem. Be sure to reset theswitch after correcting the failure condition.6 RED FLASHES: This indicates that after the unit was operating, thepressure switch opened 4 times during the call for heat. If the mainblower is in a “Delay on” mode it will complete it, and any subsequentdelay 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 beestablished. This no-light condition occurred 3 times (2 retries) duringthe call for heat before locking out. Low gas pressure, faulty gas valve,faulty hot surface ignitor or burner problem may cause this. The furnacewill lock out for one hour and then restart.8 RED FLASHES: This fault is indicated if the flame is lost 5 times (4recycles) during the heating cycle. This could be caused by low gaspressure or faulty gas valve. The furnace will lock out for one hour andthen restart.9 RED FLASHES: Indicates reversed line voltage polarity or groundingproblem. Both heating and cooling operations will be affected. Checkpolarity at furnace and branch. Check furnace grounding. Check thatflame probe is not shorted to chassis.10 RED FLASHES: Gas valve energized with no call for heat. Checkgas valve and gas valve wiring.11 RED FLASHES: This indicates that a primary or auxiliary limit switchhas opened its normally-closed contacts and has remained open formore than five minutes. This condition is usually caused by a failedblower motor or blower wheel.12 RED FLASHES: This code indicates an open igniter circuit, whichcould be caused by a disconnected or loose wire or by a cracked or brokenigniter.STEADY ON RED: Control failure. Replace control board.60-MINUTE AUTOMATIC RESET FROM LOCKOUT: This controlincludes a “watchdog” type circuit that will reset from a lockout conditionafter 60 minutes. Operational faults 6,7,8 will be reset. This providesprotection to an unoccupied structure if a temporary condition existscausing a furnace malfunction. An example would be a low incominggas supply pressure preventing unit operation. When the gas pressureis restored, at some point the “watchdog” would restart the unit and provideheat for the house.NOTE: If a flame is detected the control flashes the LED for 1/8 of asecond and then enters a flame stabilization period.
I know what 4 red flashes means, what I need to know is how to correct it. How do you close the limit switch?
Your going to have to look for a switch that looks like this. The only way you can reset these switches are if they have a small red button on top. The #4 error also makes a reference to a high limit. If that high limit is open and will not reset by itself you'll have to replace. it.
One more thing is to find out why the unit tripped. Is the air filter really dirty? or perhaps you have some supply air registers closed?
I cant seem to find anything like that. Can you look at these pictures and see if you see it? Thanks
The air filter was dirty and has now been replaced. Air supply registers closed? How do I check that?
That air filter may have done it. These pictures are very helpful. I see a limit switch on the black induced draft fan that is attached to the pvc. Looks like a brown and orange wire.The main limit is in the upper right hand corner of the picture with what looks like a white and brown wire. Then I see another limit on the upper right hand corner of the picture sitting on top of the metal enclosure that the burners are in. The high limit cannot be manually reset but the other two can. Look on the bottom of that burner enclosure too (the exact opposite side of the limit i see in the upper right).
12 years install/service experience.
There was no button on the black induced draft fan, however there was on on top of the metal enclosure and one on bottom as well. Pushed both buttons, then turned it back on. It worked for a few minutes but now I am back to 11 red flashes. Is there anything else I can try or should I call in an expert?
Do you have a meter? We can measure voltage and determine what switch is causing this.