Goodman IC Furnace fires up and quits in2-5 seconds

[jehiatt]

I'm back!

This time with my tail between my legs, a red ass and knees to match.

It took an hour driving to find the house because of wrong information. Then four and a half hours in a four foot crawl space on red dirt, and one and  a half hours making two country back road trips to the parts house.  Not to mention halfway there I remembered I didn't load my flood light and it gets worse.

 I did have my extra battery and charger for my Ryobi flashlight.

 Everybody needs to carry some old carpet pieces. I did - but it was glued to the van floor.

Anyway, this horizonal 3 yr. old Goodman unit set a 1 code after three tries. The draft fan came on, the ignitor got red hot, the gas came on like gang busters, fired up , and  quit in 2-3 seconds.

I checked everything in the unit  that I KNOW about - the series line  of the  blow out breakers, the draft air switch operation, and

then  changed the flame sensor. Then I replaced the IC controller board. Nothing ever changed. The voltage did drop off the gas valve when it quit.

Now on reflection. I could not access or didn't - the disk switch on the fan motor. It checked ok in the series check out. Maybe there is a resistance at times. Did you know WD-40 will restore some connections.

OK - you can have my goat. I can't go back over there until Monday and would rather not. I did all I could anyway I thought I was a halfway good serviceman. I don't like to be beat up but this call left me some damaged ego and cramped knees.

  Now who has a solution?

 Also -I had to charge and change the flashlight battery three times.

[dkpd1581]

Did you check to see how many inches of water column you had to the air proving switch.  Just because it makes before ignition, check to see that the reading is more than the listed value on the switch after ignition starts.  You may have a flue blockage, a dirty inducer tube or inducer wheel housing.  It is possible to have water in the inducer's housing from the condensation from cooling or a defective diaphram in the proving switch.  You may have to send 24VAC directly to the valve with a jumper to force it to run long enough.

Check you gas pressures to the manifold and make sure that it is correct and not so much as to blow out the flame.  When it does begin ignition, do all the burners light in succession?  If not clean the burners, the flame may not be getting to the last burner and heating the flame sensor in time and thus locking out the circuit.

You can also start by jumping out the safety switches one at a time to see if you have an intermittent problem with one of the bimetal safeties.  Continue until the problem leaves and the last one jumped before normal operation should be your problem child.

[jehiatt]

[user=16896]dkpd1581[/user] wrote:

Did you check to see how many inches of water column you had to the air proving switch.  NO! just because it makes before ignition, check to see that the reading is more than the listed value on the switch after ignition starts.  You may have a flue blockage, a dirty inducer tube or inducer wheel housing.  It is possible to have water in the inducer's housing from the condensation from cooling or a defective diaphram in the proving switch.  You may have to send 24VAC directly to the valve with a jumper to force it to run long enough.

Check you gas pressures to the manifold and make sure that it is correct and not so much as to blow out the flame.  When it does begin ignition, do all the burners light in succession?  YES!  But the top burner was 1/4 of the lower burner's flame .If not clean the burners, the flame may not be getting to the last burner and heating the flame sensor in time and thus locking out the circuit.

You can also start by jumping out the safety switches one at a time to see if you have an intermittent problem with one of the bimetal safeties.  Continue until the problem leaves and the last one jumped before normal operation should be your problem child.

I always learn the hard way. I forgot to take my flood light and was missing my jumper assortment. The flue was not even connected or sealed to the vent fan.  I like the suggestion to directly cut the valve on. The gas did blow out very strong. I could weld with that flame.  The top burner (4) was not anywhere near as hot or quick to light as the lower burner (1) as they fired up. I'm thinking the sensor needs to be on the bottom tube.

 I have a problem trying to figure out how that flame sensor works or can work in three seconds or maybe less. The terminal connector is a dead short to the metal sensor shaft and that is partially insulated by a seemingly ceramic insulating coating.  Where is the electronic circuit here!.

 I  reduced the gas valve input line but - no help. What is an inducer tube? I cleaned the vent fan orifice and rubber tube to the vent fan "on' switch plus removed and checked the fan insides and it's operation.

I was tested yesterday and failed. Been there before too.I want to know what was wrong, how to diagnose it better next time, and pass the info on. This is a good un!

I had obligations today that prevented my return to that job site.

A pro was called to check it out today.. No report thus far.

Thank you for your response. I can't do any more unless the Pro gets stumped also.

[jehiatt]

The heat is ON.

 A Professional found the true cause of this furnance not fully firing up. I ain't telling you what the problem was until I get a few more pertinent facts about what led up to the failure. I was totally dumbfounded myself . Stay tuned - The impossible was possible.

[dkpd1581]

Well whats the rest of the story??

[jehiatt]

I was trying to find out who caused the gas meter to be shut off and locked and why didn't the occupant know this?

Even the pro went through the check out motions but he had enough sense to finally loose the gas supply and find the pressure dropping off in three seconds - and then the cause.

There was enough gas leaking through the house meter to fire the burners strongly all three times during the test cycles. And On and on and on.

That egg on my face don't taste good!

One can see here a good example of how a home can explode unexpectedly. Just assume you removed an old gas oven  while you are rebuilding a kitchen and the gas is still bypassing the cutoff meter. Something has to light it tho. Awesome!