Goodman Furnace GDS80904BXBC new install has a 4 blink error

https://hvac-boss.com/troubleshooting/goodman-furnace-error-codes/

According to this page, you can usually fix this 4 blink diagnosed problem by changing the air filter or tightening wiring (which it has a cautionary warning about tightening such too much) and checking the flue for blockage. The furnace has activated the primary open limit circuit.

Here is a troubleshooting page about the Goodman just blowing cold air: https://temperaturemaster.com/goodman-furnace-troubleshooting/#Goodman_Furnace_Blowing_Cold_Air

Poor air flow in the Goodman caused by blockages can result in the tripping of the rollover switches which would cause it to blow cold air. That is a safety measure. You don't want gas furnaces burning with insufficient air. Think carbon monoxide. Besides the air filter, the flame sensor or the burner could be dirty. The idea of trying to DYI that cleaning job is rather off putting. I hope changing the filter would work.

I trust it is not a fuse in the pilot flame sensor circuit blown. A repairman has the voltage testers for checking the electronics involved.

I can empathize with this. My furnace, another brand, went out recently. The repair man didn't know why it went out but simply adjusted a handle controlling gas flow to a position slightly different from what was recommended and it worked. All for $200.

https://www.repairclinic.com/RepairHelp/Furnace-Repair/36-377--/Goodman-Furnace-Troubleshooting

https://www.youtube.com/watch?v=zO1jKqwXu8s

https://www.goodmanmfg.com/products/gas-furnaces

Voltage polarity switch.

When the light is blinking six times rapidly, this means the power volt polarity has gotten switched.

How to Troubleshoot a Goodman Furnace With Six Flashes

Videos as well

https://www.google.com/search?q=goodman+furnace+red+light+blinking+6+times

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There are several issues that can cause this. They range from airflow issues to bad main control boards. The airflow is easiest and it goes without saying that the filters should be clean or recently replaced. There have been cases where the controller board has retained that error and you must power off the whole furnace in order to reset it. Sometimes it requires you to replace the control board. The parts place I recommend is Goodman Furnace: Model GMH950703BXAC Parts & Repair Help ' Repair Clinic

Open high limit

There should be a chart pasted to the inside of the front access panel of the furnace. It will tell us what that particular blinking sequence means. Goodman isn't listing a gmp125-4 furnace so I need to assume it is a condensing gas furnace. I water has backed up into the draft inducing fan, the furnace will shut down. There is no reason for water dripping from the drain pan unless your A/C is running and the drain on the pan is plugged. Give me all the info. you can and exactly what is happening. Please look up the coded problem for me. I'll watch for your reply. I hope this is not too late to help.

Power is there, or no lights would blink. Steady blinking or flashing three times, stop, three times Etc

if this is an error code and you mean that the light blinks 4 times then it is the limit circuit. This could mean either the high limit or a roll out switch is open. the limit switch is right in the center of the furnace above the burner and roll out switches are probably somewhere around the opening of the burner. Follow the wires from the limit to find a roll out switch cause they are in line with each other and the rool out switch could have a button to reset it. However if the roll out is not tripped then you could need to change the limit. Only way to know is to check for continuity.

This model is equiped with a diagnostic error control. Take off the front panels and look for a wiring diagram pasted on the reverse side of the panels. On this diagram there will be a chart telling you what 4 blinks represent and where to start looking for the issue. I suspect the air filter may be dirty or the pressure switch may be bad, however make sure the condensate hoses are free of any debris. Good luck to you!

Hi 3 blinks should mean it is the pressure switch there should be a code in the manual or inside of the door

if it is the fuse on the furnace board,disconnect all low voltage wires to r-g-w-y-c.make sure you label where they go.jump out red to white if unit comes on and runs,chances are you have a bad t-stat wire or tstat.