Gas and Oil Home Heating Furnaces - Goodman GMP075-3 Problems

Hi,
I having some problems with our furnace. After checking several other forums, I have found that it doesn't seem to be a very good one. I am a college student renting a house and freezing when I should be able to study in peace. My landlord doesn't seem to think it is very urgent, but I am cold. I was hoping someone might be able to give me a little insight about what could be the problem with this piece of junk.

Things we need to know are (from your sticky):

1. In which area you live and ambient temperatures you usually experience.

Houston, TX - about 40 out right now.

2. House style and construction details.

Um, old- 1950's I think.

3. Make, model and age of equipment related to the problem.
I have heard it called Janitrol or something in forums, but the sticker on the circuit board says Goodman.

Goodman GMP075-3
SN# - 9703826937

4. Fuel type.

Gas. Are there different kinds? I am totally ignorant about these things. It smells bad. Does that help?

5. Water temperature and pressures of boiler systems. NA?
6. What type of zoning do you have with your boiler system. NA?

7. Thermostat type.
White-Rodgers
1F56-444
the manual is online (http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-4348.pdf)

7. Anything else that would be useful. No detail is to small. The more information you provide the easier it becomes for the professionals in this forum to determined the cause and correction to the problem.

OK, so about 2 weeks ago, our furnace just stopped working. I tried to fix it, despite having no idea what I was doing and possibly blowing myself up. I took of the upper vent thing on the furnace and followed the directions on the lower panel. It says basically:

(1)Turn T-stat to lowest setting
(2)Turn off all power to furnace
(3)Turn switch inside to "OFF"
(4)Wait 5 minutes and smell for gas
(5)If no gas, flip switch inside to "ON", and replace vent panel
(6)Turn bank on power to unit
(7)Turn up T-Stat
(8) Everything should be working by now.

So, I followed the directions. At one point I even flipped the breaker to the whole house just to make sure power was off. After (surprisingly) several hours of trial and error and repeating- the damn thing actually turned on. My roommates thought I was a hero. But now, it is broken again. I have no idea what caused it to stop working, except that yesterday it was warm in the house and I think my roommate set the T-Stat from "HEAT" to "SYSTEM OFF." When it got cold last night, I set the thing to HEAT again, but nothing happened.

Basically I think the problem might have something to do with the igniter. I don't know if it is just broken, or if the thermostat is not sending a current/signal (?) to the furnace to tell it to turn on. Also, when I smell for gas, it is VERY faint. I basically have to put my nose into where the gas actually burns to smell anything at all leading me to think it might be just residue? I would imagine if the unit was getting gas, I would be able to smell it very clearly much like on our stove. Is there some kind of auto-detector lock out mechanism that could shut off the gas? If so, is there a reset button?

There is the master valve on the line leading to the furnace that is parallel to the line, leading me to think that the master valve is open. The on/off switch on the inside seems to have little effect as far as I can tell on the gas coming into the machine, because I can not really smell anything. Just that VERY faint odor when I stick my nose into where the gas comes out. It smells the same regardless of how the switch is set.

The power to the unit has a switch on the inside of the closet where the unit is located. I can get the fan (at least I think it is the fan) to turn on by changing the T-Stat of the ON position and if this power is cut from the switch in the closet, the fan turns off. This makes me think I can stop flipping the breaker outside.

Regardless of whether the T-Stat is set to Auto or ON, the furnace never begins to start up. The fan (I think, or is it a blower?) will circulate the air when it is set to ON, but that is it. Before when it was working, the little metal coil (igniter?) near where the gas comes out would glow red hot, and then the whole thing would get working. Now, after following the useless instructions on the lower panel, nothing happens. It doesn't click, glow, spark, or nothing.

I read on another forum something about cleaning a flame detector (?) with a dollar bill or steel wool, which I think I tried. I found a thin rod of metal on the opposite side of the igniter that seemed to be wrapped in ceramic at a part. The top end connects to some kind of wire, the bottom end goes down to where the flames should be. I didn't actually try and take it out so much as squeeze my hand down in there and give it a little wipe down. I am not sure if this is even the right part, or if it even relates to the problems I am having.

There are a lot of wires everywhere, and I removed the lower panel to get a look at where they are going. There seems to be a little box on the right that will kill all the power if the panel is not engaged. There is a circuit board in there COVERED in dust. In another forum, I heard someone mention that there were LED's on it, but I haven't seen any at all in the whole machine. I of course put the panel back on when trying to test, and reset the machine.

The only other detail of note that I can offer, and probably the most important has to do with the T-Stat. Before, when it was working, It would seem to spark or something when it started the furnace. If I remember, it sparked just next and to the left of the little mercury bubble. I guess normally you wouldn't see this with the case on it, but our case was off. The little covering doesn't snap into place like it is supposed to, and can come off whenever you try to adjust the temp. I also remember at least hearing some type of click or something the last time I "fixed" it and it clicked on. Do you think if I replace the T-stat, it might fix it? Is that hard/dangerous?

Any help or ideas anyone has would be GREATLY appreciated. I have no idea how these things work (I am studying accounting, maybe I should transfer to EE). Sorry for being so wordy, but I didn't want to leave any info that might be useful out.

Thanks for reading everything, and thanks in advance for any ideas!

Regards,
Freezing in Houston

OK, so I thought I should check the LED thing out again and this time started the unit from the T-Stats with the bottom panel open. I manually held in the auto-power off (usually held in place by the bottom panel) and checked out the circuit board. There is in fact and LED light, and a trouble shooter on the back of the bottom panel to go with it. The light doesn't blink or do anything when the unit is activated, and according to the troubleshooter, everything is normal. Could the diagnostics be wrong, or does this mean the T-Stat is broken?

Goodman makes Janitrol, and other brands.
Lets start with the basics. Turn the thermostat down so it doesn't call for heat. Switch the power to the furnace off then back on. Remove the upper panel only, so you can see the burners. While watching, have someone turn up the thermostat so it calls for heat. If nothing happens, it may be a bad thermostat. If the small purge blower comes on, that's good. Watch the area of the burners. You should see the ignitor glow after the blower has been on about 15 seconds. if no glow, the ignitor is bad. If it does glow, the gas should then come on and the burners ignite. No gas is a bad problem and a pro needs to be called in. If the burners do light, but go out after a few seconds, the flame senor is bad.
Let us know what you find from this test and we will do our best to help you.

Thanks for the help!

I turned the heat all the way down, turned off power, and clicked the on/off switch back and forth. Turned the power back on, raised the thermostat to call for heat.

I was watching very closely and it appears nothing is happening. The machine doesn't make any noise and the igniter does nothing.

You think it is the Thermostat then?

From what you described about the thermostat, it sounds like it is bad. The wiring is only around 18 volts so it can be changed out easily. If you replace it, note where the current wires attach, and their color. Then match up the new thermostat. The terminals on the thermostat are marked for the color wire to be attached. There will be further instructions packaged with the new thermostat.

everett,

You are treading muddy water by trying to fix your landlord's furnace. Do not touch it! Legal issues.

Goldstar,

You were right! It was a broken T-Stat. I replaced it tonight and everything is working great. I wish I would have known it would be this easy sooner.

Thanks for everything!