Translate four LED flashes to mean your furnace has a primary limit circuit open, possibly from loose wiring or blocked filters. Check and clean filters, tighten wiring and check the flue for blockages.
I'd say it's the control board at fault of the error code pops up immediately AND you have verified that the hi limit input/return signal is present at the board confirming all limits are closed. Goodman boards when failed internally often do this and go to an error status immediately upon call for heat and usually is the last fault code it encountered. I've seen this dozens of times and almost every time it was the result of water damage on the board from an AC issue usually long before the heating problem. So if you see any signs of water having been on the board that's something to address before wasting another board.
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
SOURCE: Coleman furnace blower runs continuously
You should be seeing 120 volts to the igniter. Anything less requires either a replacement of the transformer, start relay or control module.
SOURCE: Goodman furnace GMPN080-4 Getting 4 RED blinks/Open Limit Swtch
You have a limit switch located in the furnace (a little bigger than a dime and located near the center of the front panel, sometimes the switch is mounted to a small fiberglass board) . There will be two wires going to it. They sometimes trip so often that they fail to automatically reset(due to dirty filters or undersized ductwork). You can SHUT OFF POWER TO THE FURNACE, then remove the two screws holding the switch in the furnace, pull the switch out of the furnace and tap on it and wipe it off.
The switch may work a few more times but should be replaced with the same size and type. You will see some rating printed on the switch somewhere. Write down all the numbers and get a replacemet from a furnace/AC supply house. If you have a meter and know how to use it you could check the switch for continuity.
Sometimes just a tap on the switch will get it going. There will also be a couple of rollout switches that could be tripped. They have little buttons on them to reset them. If they trip it may have other issues to be solved.
Hope this helps!
Matt
SOURCE: Goodman Model GMNT100-4 Auto Power Down and Up until Temp.
Keep in mind all furnaces and circuit boards are not the same. Look on the back of the door to the blower compartment. You should find the list of diagnostic codes. Look up four blinks it should narrow down the problem. Although from the discription you gave it sounds lie the high limit control. When a high limit appears to be acting up it DOES NOT mean that the high limit needs replaced. The high limit just may be doing its job. This means that the furnace is overheating. Check your filters. Are all of your registers open? Is your blower set on the right speed? Is your blower going bad? Is the blower motor capacitor bad? Is your evaporator coil restricted? Just changing a high limit switch does not always solve the original problem!
Good luck....
SOURCE: Goodman forced air gas furnace not firing
if your power vent moter is not running you should not have have glowing ignitor.Frist the vent moter must close an air prove switch in series with the idnitor .seems you have a stuck air prove switch.Its the one with a hose attached
SOURCE: goodman gmnt100-4b wont ignite
I had the same problem. I had to remove a return air duct filter that i had installed and it worked just fine. The system needs plenty of air flow to operate.
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