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  • Gas furnace question...

    Okay...need some help here. I have a gas furnace in my attic. It says Quattro by consolidated industries on the side. My problem is that the burners will not ignite. When I turn on the heat, I can hear te "igniter" buzzing and I can smell gas, but they will not lite and subsequently, the fan does not come on. Now, once or twice, especially in the morning, the burners did ignite, and the fan came on and blew hot air just like it was supposed to. But, after the cycle was complete, it would not come back on...I listened for it, and once again, the igniter buzzed, I could smell the gas was there, but then nothing. I can switch the fan to ON and the fan will come on, so I am almost positive that the fan is not the culprit. The AC works just fine. So, I did a little research, and I suspect it may be the "thermocouple"? (spelling?) I was calling it an "igniter" in laymans terms...Any ideas out there? I have not pulled the cover off of the unit to examine it, but I am capable of doing so if someone wants to help me out...there is a gas shut off valve leading into it as well as an electrical switch to shut power off going to the unit for service I am assuming. I have a full array of tools and a full function volt meter, so, I just need an idea as to where to start and on what...It's not freezing here, but the wife is cold and I would like to see if this is something I can repair myself. ANY help would be appreciated and THANKS in advance!
    Nick

  • #2
    Re: Gas furnace question...

    Lisa,
    Thanks for the quick reply. I am getting ready to go into the attic and follow your advice. If your still on here when I get back, I will post the results and you can let me know from there. THANKS SO MUCH! Be back soon...I hope.
    Nick

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    • #3
      Re: Gas furnace question...

      Okay...followed your instructions to the letter. I SAW NO SPARK AND NOTHING GLOWING. I am not sure if my unit uses a standing pilot or if it just has an electronic ignition. There is what looks like the boot of a sparkplug wire that connects to a small metallic tube and that small metallic tube is RIGHT next to a skinny gas line. That skinny gas line is fed by a small box like device that has a brown gas valve on its side that says pilot in one direction and off in the other. So, I am guessing that the unit uses a pilot? BUT why would it work sometimes and not all of the time...unless it only ignites the pilot temporarily each time instead of the pilot staying lit all of the time....Any suggestions?

      Comment


      • #4
        Re: Gas furnace question...

        HIS

        Let's hope some real HVAC Techs come in here and try to help you. Can you please post pictures showing everything close up? That would be most helpful for sure. The problem is that words only go so far to describe something and especially when you're not real sure what is what. Pictures are always helpful.

        For now please shut off the gas valve and power to your furnace. This is for safety reasons. Maybe you can use a good electric heater or wrap up in nice warm blankets and PJs and socks for now. No matter what you should have a good licensed HVAC Tech check it over soon.

        Comment


        • #5
          Re: Gas furnace question...

          Ok...figured out that this unit does not use a standing pilot. I was wrong about the small brown valve inside the unit...it only has an ON and an OFF position...no PILOT position. I think there is a problem with the electrical component that sends the SPARK down the conductor wire to the igniter that ignites the temporary pilot. It seems like it just buzzes loudly...like it is TRYING to send a spark, but can't. There is definately gas going to the temporary pilot...but just no spark. I am assuming that the actual igniter element could be faulty...it looks like it can be replaced as I think I can see threads on it. Not sure if the buzzing from the other component that it is attatched to is normal.

          Comment


          • #6
            Re: Gas furnace question...

            Originally posted by Woussko View Post
            HIS

            Let's hope some real HVAC Techs come in here and try to help you. Can you please post pictures showing everything close up? That would be most helpful for sure. The problem is that words only go so far to describe something and especially when you're not real sure what is what. Pictures are always helpful.

            For now please shut off the gas valve and power to your furnace. This is for safety reasons. Maybe you can use a good electric heater or wrap up in nice warm blankets and PJs and socks for now. No matter what you should have a good licensed HVAC Tech check it over soon.
            Thanks Woussko...I did shut the gas off. My digital camera has been shot for a while now and I just haven't got around to buying a new one, so pics aren't possible right now...sorry. It's not that cold here tonight, 37F or 38F, but she is cold natured. Anyway, we are fine and in no danger of freezing to death. I think I did manage to narrow it down to one or two components. I will most likely call a professional tomorrow, I just thought I would try my luck here first. Thanks again...I always enjoy your posts.
            Nick

            Comment


            • #7
              Re: Gas furnace question...

              Before you put too much money into repairing the FAU make sure you check the firebox. The Consolidated Industry FAUs had a lot of problem with the exchangers including 50 or so fires in nox furnaces. I've never heard of a fire in a non-nox FAU but have heard of plenty of bad exchangers.

              Mark
              "Somewhere a Village is Missing Twelve Idiots!" - Casey Anthony

              I never lost a cent on the jobs I didn't get!

              Comment


              • #8
                Re: Gas furnace question...

                The buzzing sound you hear is probably a bad or shorted igniter. It should be sparking right in front of the pilot outlet. Try to light the pilot with a long match or grill lighter to get heat temporarily.

                Comment


                • #9
                  Re: Gas furnace question...

                  The spark will travel the path of least resistance to ground. You may have a cracked insulator from the spark generator to the electrode or more likely with the humidity there you have rust in the area that surrounds the electrode tip where the spark is supposed to jump causing it to find an easier path to ground. If you can get the igniter out clean it up and try again, over time the heat can also cause the gap to widen at the electrode tip

                  Comment


                  • #10
                    Re: Gas furnace question...

                    Originally posted by ToUtahNow View Post
                    Before you put too much money into repairing the FAU make sure you check the firebox. The Consolidated Industry FAUs had a lot of problem with the exchangers including 50 or so fires in nox furnaces. I've never heard of a fire in a non-nox FAU but have heard of plenty of bad exchangers.

                    Mark
                    Thanks Mark. I am guessing that the exchanger is the box where the ignition spark comes from and travels down the shielded conductor wire to the igniter element? The box is metal and I think it has a warning sticker posted on it stating danger of electric shock. Is it possible that the shielded wire has a break inside somewhere?
                    Nick

                    Comment


                    • #11
                      Re: Gas furnace question...

                      Originally posted by plumberscrack View Post
                      The buzzing sound you hear is probably a bad or shorted igniter. It should be sparking right in front of the pilot outlet. Try to light the pilot with a long match or grill lighter to get heat temporarily.
                      I watched it closely and I didn't see any spark. Is it moderately safe to try to light it myself?

                      Comment


                      • #12
                        Re: Gas furnace question...

                        Originally posted by wbrooks View Post
                        The spark will travel the path of least resistance to ground. You may have a cracked insulator from the spark generator to the electrode or more likely with the humidity there you have rust in the area that surrounds the electrode tip where the spark is supposed to jump causing it to find an easier path to ground. If you can get the igniter out clean it up and try again, over time the heat can also cause the gap to widen at the electrode tip
                        I am going to check the insulator with a meter for continuity to make sure that the conductor is not broken. I will also try to remove the electrode tip and clean it as you suggested. Are these parts available at the BIG BOX retailers or will I have to go through a supply house?

                        Comment


                        • #13
                          Re: Gas furnace question...

                          Originally posted by ToUtahNow View Post
                          Before you put too much money into repairing the FAU make sure you check the firebox. The Consolidated Industry FAUs had a lot of problem with the exchangers including 50 or so fires in nox furnaces. I've never heard of a fire in a non-nox FAU but have heard of plenty of bad exchangers.

                          Mark
                          One more thing Mark,
                          If I have to replace the "firebox" is it available at a retail level or is it a technician only item? Do you know what they cost? Thanks again!
                          Nick

                          Comment


                          • #14
                            Re: Gas furnace question...

                            Originally posted by Home Improvement Solution View Post
                            One more thing Mark,
                            If I have to replace the "firebox" is it available at a retail level or is it a technician only item? Do you know what they cost? Thanks again!
                            Nick
                            The firebox or heat exchanger is that area where the burner is which heats up and the fan blows over it. It is pretty much the heart of your heating system. When Consolidated went BK they were bought out by Texas Furnace. I'm not sure whether new fireboxes are available any more. That's why I suggest you check the firebox before putting any money into fixing the rest of it.

                            Mark
                            "Somewhere a Village is Missing Twelve Idiots!" - Casey Anthony

                            I never lost a cent on the jobs I didn't get!

                            Comment


                            • #15
                              Re: Gas furnace question...

                              AH...I see. Thanks for the info. I am by no means even close to being qualified to diagnose the problem with this unit. I think though, that I may have isolated the problem. I will give you a rundown of what I have found, and you tell me what you think. I pulled the igniter assembly out and just like Brooks said, it was indeed rusty. So, I cleaned it with an ignition file and made sure to wipe off the dust. I then reinstalled the assembly making sure that it went back in EXACTLY as I took it out. So, I turned the gas back on and and switched the power back on, then turned the thermostat on. Well, the same thing happened...it buzzes but no spark. So, I pulled the shielded cable that looks like a spark plug wire and tested it with a meter for continuity. All was good there. So, I figured that it had to be one of two things. Either the igniter itself is just BAD or the unit that sends the spark down the wire is bad. (it looks like an high performance ignition from a car..haha) Anyway, I used a voltage DETECTOR while the unit was cycling at startup to see if voltage ws flowing down the conductor wire to the igniter and sure enough it was. So, at that point I thought, IT HAS TO BE THE IGNITER itself. So, I once again removed the igniter assemby and faced it towards me and this time I shut the gas off to see if the igniter was sparking. I turned the thermostat on, but this time there was NO BUZZING sound but there was voltage flowing to the igniter...hmmm...I assumed at this point it had to be GROUNDED by the install screws in order for it to work. So, I reinstalled it and turned the thermostat back on and tried to peer inside while it was starting, and now it STILL won't buzz. There IS current flowing to the igniter though. Hmmm...So maybe the electric ignition was really bad after all? If thats the case, It only has a five wires and one cunductor wire connected to it, so, if I could purchase one outright, I'm sure I could install the new unit. What do ya think?
                              Last edited by Home Improvement Solution; 11-08-2007, 02:02 PM. Reason: addit.

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