Gas furnace not igniting – Goodman furnace wont ignite – DIY Gas furnace repair

Hey, I'm Shane with a handle on things If you've got a Goodman brand 
furnace like the one I've got, or any other gas operated furnace and the furnace won't turn on or the furnace won't ignite a basic understanding of how gas furnaces operate might save you a lot of trouble, 
and maybe a lot of money so stick around I'll show you the four main things that usually fail and keep a gas operated 
furnace from working properly and I'll show you how I fix them on my furnace So here's my situation, I live a gazillion miles from nowhere and I have a Goodman gas furnace that 
provides the primary heat for my house and every year or two when summer comes to a close I turn on the furnace and something doesn't want to work right with it.

Well guess what… summer just came to a close I turned on my furnace and it doesn't want to light. Well let's see if we can sort this out and 
get a handle on things in the furnace room! My furnace is located in a small furnace room so getting to it can be a bit tricky especially for filming Here's a quick tip! Put your furnace model number and serial number in a spot where they're very 
easy to find when you need them This will save you a lot of aggravation later Let's pull the access panels 
off the furnace and have a look I'll remove the top panel 
where the burner is located And the bottom panel where the 
control board can usually be found In the bottom compartment 
there's a safety door switch If the plunger on this switch is out of 
position because the access door is off   the furnace won't run The control board has line voltage supplied to it in my case that's 115 volts I'll be careful what I touch in here ! In the upper compartment 
we find the pressure switch It's attached to the blower fan with a rubber hose This is the burner assembly On the flame side of the 
burners we find the igniter Hey could you do us a favor? Take just a second and hit 
that like and subscribe button! You wouldn't believe how 
much it helps the channel out thanks! …and the flame sensor On the side of my furnace is 
an electrical shutoff switch…

And the gas supply shutoff valve all of the switches and sensors on the 
furnace connect to the control board my furnace isn't lighting so I'm going 
to have a look at the igniter first the igniter is connected by a 
plug in the upper compartment After shutting down the breaker to the furnace 
and shutting off the gas supply for safety I'll detach the igniter at the plug The igniter is held in place 
with two sheet metal screws After removing the screws 
the igniter lifts out easily This igniter has a lot of soot built up on it and I found a crack in the porcelain So I'm going to replace it I ordered a new igniter from eBay it cost me about 15 bucks the furnace part shop in town wanted 
60 bucks for the same igniter! I inspect the new igniter there should be no breaks in the coil everything looks good The holes in this mounting plate 
are the same distance apart as   the other igniter so it's looking good so far I install the new igniter and plug it back in The plug is set up so it 
only goes together one way can't mess this one up While I'm at it I'll clean the flame sensor it's also located in front of 
the burners on this furnace I remove the one screw holding 
it in place and pull it out The flame sensor also has soot on it it doesn't have to be very dirty 
and the furnace will start acting up so I'll clean it The flame sensor is cleaned with acetone Fingernail polish remover that's the same thing I never use abrasives to clean this sensor There's only one wire attached 
to the sensor and it looks okay I reinstalled the sensor the pressure vacuum switch tells the control 
board that the burner blower fan is working It knows that because the fan 
creates a suction through the   rubber tube that trips the pressure switch I detach the rubber hose and verify 
that the hose is in good condition Then I suck on the rubber hose 
and listen to the switch click This is an indication that the suction 
will cause the switch to operate This doesn't mean the switch is good, but it does mean it's tripping 
with pressure at least I've had plugged hoses But I've never had a bad switch…

Well… yet I plug the hose back into the fan housing after replacing the igniter, cleaning the flame sensor, and checking the pressure switch, I check to see if the furnace is now working Usually it'll work fine at this point and 
i can close up the furnace and move on. I've turned the thermostat up, turned the gas on, and turned on the power.

pexels photo 5877455

And I'm holding the door switch 
in to check the furnace operation The burner fan has come on 
and it's evacuating any gas   that may be present prior to the ignition sequence Well at this point the 
igniter should start glowing but that isn't happening that's not a good sign after about two minutes the furnace 
starts blinking a failure code this is a single flash code it keeps repeating but it's a single flash code I check the chart to see what 
a single flash code means and I have an ignition failure I've already checked the things it says to check a quick look at the furnace 
schematic tells me that the   igniter should be getting 115 to 120 volts 
of ac power when it's supposed to initiate the schematic says that bold lines 
are high voltage and thin lines   are low voltage on this furnace Now this is a multimeter You can get one at a home improvement 
center for as little as 10 bucks You really ought to have one I set it to read up to 200 volts of ac power And I plug the leads into the wires that are 
supposed to supply the line voltage to the igniter It doesn't matter which lead 
goes to which wire with ac power Then I cycle the furnace again to see how much   power the control board is supplying 
when it's time to ignite the furnace Well the control board isn't sending any 
power when it's time to ignite the furnace.

I now know that something is 
wrong with the control board After all, the igniter can't 
work if it isn't getting power so I shut off the breaker and 
the gas supply again for safety the control board is mounted to the furnace 
on a series of little plastic buttons A little squeeze on the plastic buttons 
and they release the control board  easily The control board part number is printed 
in the margins of the control board I'm going to need this so that 
I can order a new control board Well…

Now I guess we know why the 
control board quit me don't we This mouse shorted the high voltage 
side of the control board with his body He won't be doing that again anytime soon! I found a new control board on 
eBay for less than 100 bucks The furnace parts store in town? Yeah… they wanted 200 bucks for the same board Try not to give the new board a static shock? Well, tell that to the mouse ! I checked the part number on the new board… people make mistakes sometimes. this looks like the right one though Then I checked the paperwork 
that came with the new board to make sure they haven't made any improvements 
that are going to require my attention no surprises on this one that's good now we're going to remove the wires 
from the old board one at a time and plug them into the correct 
locations on the new board one at a time is the key that way you can't get confused the nine pin connector can only 
plug in one way that's a no-brainer okay I one-at-a-timed my way through 
all of the wires and connections and the new board is now all hooked up I'll pop it back onto the 
little plastic mounting buttons Time to turn on the breaker 
and the gas supply again And then I'll hold the door switch in and we'll see if the furnace will light this time if all things are working the igniter 
should start to glow after about a minute and there it is and…

the furnace lit and it kept running! now that's a good deal! now just for those of us who want 
to see how many volts the igniter   should be getting if the board is working right There it is… 123 volts ac that's line voltage in this case I zip tied all the wires again… and I'm going to clean up this 
filthy furnace just a little bit And with the access panels back on my furnace 
now works exactly like it's supposed to Well, I'd say that I saved myself 
about 600 bucks on this project ! but the truth is that most of the furnace guys 
I've run into don't like replacing control boards they would have just tried to 
sell me a new furnace instead So i saved a ton of money!.

As found on YouTube

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