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Need help with a goodman gmt070 furnace...error code flashes three times, i have replaced pressure switch, still flashed, replaced board, still flashes three times...flue is clear, draft inducer motor is good...
You need the correct diagnosis to fix the problem. Without knowing what the error code means you're replacing perfectly good parts till it works, and that isn't the way to troubleshoot.
What is it not doing in the sequential cycle of start up events? The power vent motor should start and stay running, then the gas should ignite, all the burners should lite and then the blower motor runs.
If the power vent motor quits, the flue could be too small or the vacuum pressure switch is still bad.
And the error code means?????????????
You need the correct diagnosis to fix the problem. Without knowing what the error code means you're replacing perfectly good parts till it works, and that isn't the way to troubleshoot.
What is it not doing in the sequential cycle of start up events? The power vent motor should start and stay running, then the gas should ignite, all the burners should lite and then the blower motor runs.
If the power vent motor quits, the flue could be too small or the vacuum pressure switch is still bad.
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Re: Need help with a goodman gmt070 furnace...error code...
It may be clogged at the barbed fitting on the induced draft motor where the pressuer switch tubing connects. take a paper clip and **** it out make sure you can stick it thru freely till you can feel the Inducer wheel then reconnect and try again.
Thank you, mac5932002, I had this same problem and the paper clip solved it, furnace is running again. Quick question, where does whatever it was that clogged it go? Does it just get blown out the flue?Thank you, mac5932002, I had this same problem and the paper clip solved it, furnace is running again. Quick question, where does whatever it was that clogged it go? Does it just get blown out the flue?
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Gas furnaces has safety features to prevent explosions. If anything is thought to be faulty, nothing works. All gas appliances must be repaired by a registered gas technician. The two pressure switches are $76 and $29 if you want to risk it.
Verify if a 120 volts is being sent to the igniter after the pressure switch closes, if you are not receiving 120 to the igniter this could be a faulty control board. If you are receiving 120 then most likely the ignitor is faulty.
Any light flashin on the control board? If not then look for a small fuse blown on the board. See lights a flashing count them flashes
A sampling of various failure codes on a furnace:
Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.
Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.
Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.
Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.
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.
Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.
Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.
See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.
Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.
Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.
Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.
Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.
Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.
Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.
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.
Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.
Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.
See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.
Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.
Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.
Improper ground from control to burner. Incorrect electrical wiring, check polarity. Tubing partially clogged between inducer and proving switch.
A sampling of various failure codes on a furnace:
Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.
Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.
Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.
Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.
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.
Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.
Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.
See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.
Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.
Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.
Goodman have troubleshooting idiot lights on the board. Look for flashes and count em. The flash explanations are printed on the backside of the blower cover on most models. A sampling of various failure codes on a furnace:
Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.
Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.
Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.
Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.
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.
Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.
Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.
See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.
Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.
Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.
That thang might be sensing a lazy flame. In other words the flames took too long in the board's opinion to quit sensing the flame. Yall probably need to do pressure tap on the gas valve. Here is a realistic look at goodman fault codes and what to check fer and I am assuming you are not a tech and don't know this already and am hoping it helps:
Read one LED flash that stays on continuously to mean your furnace has no signal coming from the thermostat and will not operate. Turn the power off and check the thermostat for improper settings or connections.
Interpret one LED flash that blinks on and off to mean your furnace has locked out because it could not ignite after three tries, and must be reset. Interrupt power to your furnace for 20 seconds or lower the thermostat so your furnace does not try to heat, then reset the thermostat to the previous setting. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual.
Decipher two LED flashes to mean the draft blower is not working, or your furnace has a short in the pressure switch circuit. Turn off the furnace power and repair a short or replace the pressure switch.
Read three LED flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating. Check the pressure switch hose of your furnace for blocks or an improper connection. Also, look for blockages in the flue, and tighten any loose wiring.
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.
Interpret five LED flashes to mean your furnace senses a flame without a call for heat. This could be from a gas valve closing slowly or a burner flame lingering.
Read seven LED flashes as a warning of a low flame sense microamp signal. This could happen with a coated flame sensor or a lazy flame from poor gas pressure. Turn off the power and adjust the gas pressure according to the information on the rating plate.
See eight LED flashes as meaning an igniter circuit problem due to a bad igniter or an igniter connected improperly. Replace the bad igniter or check the ground wiring, making necessary corrections.
Decipher nine LED flashes to mean the high-stage pressure switch circuit will not close during a high-stage-induced draft blower operation. Your furnace may have a pinched or blocked pressure switch hose, a blocked flue or loose wiring.
Read continuous flashing on the LED to mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram.
Now here is how it should all go down:
Bottom dollar: it all goes back to type of gas, the initial setup, the pressure tap. and how it is wired up to begin with. This will give you an idea where to start I hope.
Hi, what you have to do is where you see this light flashing, there is a circuit board. Remove the panel. If everything goes black, you have a door switch on the perimeter that you can tape down to restore power to the furnace. On the panel, you will find a error code sheet glued on it telling you what the flashes mean. 3 flashes may say you have an open pressure switch, or 4 may say the inducer motors off or something else. It will almost troubleshoot itself. Find out what the 3 flashes mean and if you cant figure out what to do, contact me and I will walk you through it. It sounds like you have a dirty flame sensor, or an intermittent problem in the ignitor module. Check it out as it will tell you. Sincerely, Shastalaker7
Combustion fan purges the heat exchanger. A pressure switch verifies combustion air fan is running. Usually a 30-45 second purge before the hot surface ignitor glows, or the spark ignition starts.
Gas valve opens after 10-15 seconds and main burners light. Control board monitors for flame and shuts gas valve after 2-3 seconds if main burner does not light.
If burner does not light, some boards repeat this for 3 tries, then locks out and is reset by cycling power.
Air blower comes on after another 30-45 seconds after main burner ignition.
Times may vary based on the specific controller board. A flow chart and timing sequence should be located somewhere on the unit, usually in the fan compartment.
Ok, a flashing 3 on a Goodman control board usually means that the pressure switch is tripping. A few things will cause this. One being a restriction in the exhaust or combustion air inlet. The second could indicate a faulty inducer blower motor and the third would be a blocked or bad pressure switch. With the front cover off and door switch taped down, Have a helper turn the thermostat up to 75. You will be watching the circuit board for flashing lights and in a few seconds the inducer motor (the small fan hooked to the exhaust) will start. If this does not happen, we either have a bad circuit board or blower motor. If the fan starts rotating, inspect the hoses going to the small circular pressure switch. Sometimes they may get either water or debris in the hose and not allow the switch to sense pressure. If the hoses look OK, the igniter will glow an orange color and you will see this if you look thru the small viewing port. IF no glow, you could have a bad pressure switch, a bad ignition relay (found on the circuit board) or a bad igniter. OK so if the igniter glows, a few seconds later the gas valve should click open and send gas to the burners. The orange will turn to blue. If this does not happen, you have either a bad gas valve or bad circuit board. Finally if you get flame but it will not stay lit more than a few seconds, you may have a restriction in the burner gas train, a bad gas valve, a dirty or bad flame sensor or not enough gas pressure. Knowing the sequence of operation will give you the needed information to talk with a service technician and cut down on diagnostic costs. Try looking on the back of the furnace access panel for both model number and a diagnostic schematic. This will confirm what the flashing 3 code means for your unit. Sorry, without knowing the model number, this is the best I can do for you. Good Luck!
And the error code means?????????????
You need the correct diagnosis to fix the problem. Without knowing what the error code means you're replacing perfectly good parts till it works, and that isn't the way to troubleshoot.
What is it not doing in the sequential cycle of start up events? The power vent motor should start and stay running, then the gas should ignite, all the burners should lite and then the blower motor runs.
If the power vent motor quits, the flue could be too small or the vacuum pressure switch is still bad.
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