Reverse polarity my carrier gas furnace model number 58SAT is saying reverse polarity the blower will come on but it will not light the polit i have even called a tech and he doesnt know either he has been coming for 3 days and still nothing

Those are called 'flash codes' and are an aid to diagnostics. Google

make model flash codes

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You need to have/ know the "fault code" chart for that specific furnace. Count the number of flashes and refer to chart. Look on the inside of the furnace blower door or other panel. Also look up on internet and print it off. If the furnace was allowed to run during the remodel it voids the warranty automatically. Read the installation manual.
Try resetting the electronic board by turning the power off then back on.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/dan_77d17b8918f54455

Make sure the kill switch on the blower door is closed, or furnace won't do anything. Then remove power from furnace for a few seconds, then try again. Still no go? Take a jumper wire and jump the "r" terminal to the "w" terminal on the furnace's board. This bypasses the thermostat. This is only for testing. If it still wont run, call service guy. Gas furnaces are not good things to tinker with.

check the green ground wire, make sure it is connected

What is the model number? I have an SLP98 (installed on 11/29/2011).... and if I take the cover off the front of the furnace the panel that has the fancy "Lennox" badge on it) you will see two clear round windows about the size of a half dollar (one high on the furnace box and one lower on the blower box.) If you look downward into the window on the blower box you can see a red LED display that will sometimes flash error codes like E228 (one character at a time). If your model has something like this, let me know. I've done some DIY fixes recently out of necessity....and their easy.....and several technicians confessed they didn't know much, if anything, about the newer high effieciency Lennox gas furnaces.

Gas regulator or flame sensor for all GMT models

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.

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

Troubleshooting and Repair
Furnaces with electronic ignition systems may be much more efficient than their early counterparts, but they do it largely through electronics. However, there are still some troubleshooting you can do but fixing the problems can involve replacement of parts more so than repair or adjustment. PROBLEM: Furnace burner will not ignite
Possible Solution

• With a Hot Surface Ignition (HSI) system, if a gas hissing sound is heard for about 7-10 seconds and the burners do not ignite, the furnace will go into lockout mode.
• To reset turn the furnace power switch off and back on and try again. The switch is probably located on the side of the furnace. A reset button may also be found on the solid state controller. If resetting fails again, proceed as follows.
• Turn off power and gas to the furnace
• Remove and check hot surface igniter being careful not to touch the heat element. If it is cracked or damaged, replace the igniter.
  PROBLEM: Furnace comes on for 7-10 seconds then turns off Possible Solution:
  
  • Turn off power and gas to the furnace
  • Remove flame sensor from its bracket. Lightly clean the surface with fine emery cloth and replace.
  • The problem may also lie in a bad ground or the the black and white wires being reversed (reversed polarity) at the junction box or outlet powering the furnace.
  • The electronic ignition control module must ensure current flow through the flame sensor to ground and if the polarity is reversed in the circuit there is no voltage potential and the flame sensor does not work and closes the gas valve.
  • If the black and white wires are connected correctly and the flame still drops out, then the issue may be a bad ground. Using a volt-ohm meter, measure between the white wire and the ground wire to be sure you have no voltage.

carrier gas furnaces will try to light three times then will usually go on a lockout for one hour you can bypass the lock out by resetting the power, turn furnace on, remove wires from gas valve, you will need a multi meter to check for voltage to valve, if control board sends a call to the gas valve the valve is bad, if voltage is never present during the lighting cycle your control board is bad