The unit will go through a heat cycle but the combustion and circulating fans will not shut off, it has had two new boards put in it and is still doing the same thing. Every component in it checks out as good but the fans will stilll not shut off.
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Re: Older model Goodman gas package unit
It sounds like it is still receiving a "call" for heat from the thermostat. First check that the thermostat is set for gas heat and not electric.(There may be a jumper or dip switch on the back). Read the directions with the thermostat.
Secondly, Verify that the wiring at the thermostat is correct. (R- to red, W to white, G to green etc.)
Third, If the first two do not fix the problem, then there is definitely a problem in the thermostat wire between the furnace and the thermostat. (usually the "R" and "W" wires will be crossed or shorted to the sheet metal around the furnace. You may just have to replace the entire wire. Best of luck!
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Hello,Good job with description.Something is keeping the condenser off(saftey).Do you have an emergency heat setting on the therm.It will run electric heat strips only until service can check it out.Very rare that the disconnect switch (black box) is it.Need electrical meter to prove it out.
There is a induced draft motor that will run first to purge the combustion chamber and induce a draft, a pressure switch closes proving an induced draft exists, thus allowing the spark and pilot gas, or hot surface ignitir and gas to pilot rsil and /or burners, a trial period for ignition about 30 seconds each for 3 attempts will be made and if not lit by the 3rd attempt it locks out, requiring a reset of power to unit to reset the module or circuit board etc. 1st see what motors running, is it the flue exhaust motor/induced draft??
Check near the squirrel cage fan and see if there is a sail switch. Sometimes these are used to confirm air movement prior to firing off the gas furnace. It is simply a square piece of metal on a stick that attaches to a microswitch. This switch is then depressed when the fan pushes the air (and the metal piece) allowing the burner to fire off.
Hope this helps.
There is a vacuum sensor on most units tied from the exhaust gas fan to the sensor. Does the unit try to start? If the unit's exhaust fails to pull the switch it will turn off after about 30-45 sec after starting. "IT" thinks it's not exhausting and stops to keep from overheating. Do you have this exhaust fan and rubber hose to sensor? Can you see if that fan is turning on start?
Cycling the external switch on the GMS series will not help you. That switch is for A/C only. At the unit found inside the house, remove the front cover. If there is a door switch, tape it closed. Now if the thermostat is calling for heat, the unit will cycle as you mentioned. When the unit does not start, check for a blinking light on the circuit board. After three unsuccessful tries, the light will blink a code (2 blinks then a pause up to 9 blinks than a pause). Make a note of how many blinks you see. On the reverse side of the access panel you will find a diagnostic schematic. It should tell you a fault code corresponding with your blinking. This will give you a starting point where to look. If the codes are not found there, check inside your owner's manual. Or you can call Goodman at 713-861-250. Get back to us with those codes and maybe we can help you further.