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  • #16
    Originally posted by Sparky_NY View Post
    Flame rollout switches are commonly a small maybe 1/2" dia disk type switch, commonly have a red reset button on the back side.
    They are not a common failure item, if they trip there most likely is a problem. Blocked flue, delayed ignition, back draft are just a few common causes.

    Here is a typical one
    https://www.acunitparts.com/amana-go...350f-b1370154/
    All the ones on ours are the ~~5mm x 12mm thermal fuses. One-shot and done, although they did supply an extra, I believe.

    I suspect that the makers did not want someone resetting over and over as they fill the house with stack gas.
    2801 3147 6749 8779 4900 4900 4900

    Keep eye on ball.
    Hashim Khan


    It's just a box of rain, I don't know who put it there.

    Comment


    • #17
      The furnace has been running, and I'm keeping a close eye on it. I see the occasional lick of flame backing out of the burner cavity, but it's also been quite gusty here so I'd expect a bit of that. I don't have any odd smells or anything, and the CO detector has not gone off.

      I think I'm at my three things going wrong at once now- first the clogged sewer line, then the furnace, then this am the main saw at work quit. While I was fixing that, one of the guys told me that the other saw suddenly wouldn't turn off. Fixed that, then finished the repair on the main saw. After a beer and a bite at the pub, I'm home and looking at my gas bill. Cost of gas, $65- total bill $280. They claim a rate increase of 8%- storage and transport is up 40%. The carbon tax is almost as high as the gas cost. I feel like I'm getting raped-
      I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

      Comment


      • #18
        Originally posted by darryl View Post
        The furnace has been running, and I'm keeping a close eye on it. I see the occasional lick of flame backing out of the burner cavity, but it's also been quite gusty here so I'd expect a bit of that. I don't have any odd smells or anything, and the CO detector has not gone off.
        .....................-
        There should not be any of that at all..... That's the reason for the "hood" I mentioned. The "hood" usually has the stack gas from the top of the heat exchanger coming out of that compartment sideways into an adjacent open-bottom compartment that has the stack pipe coming out the top of it.

        If air gets blown down the chimney, the open-bottom compartment lets it go somewhere other than into the burner area. That way the pilot (if any) does not get blown out, and the flame is not rolled-out of the burner area.

        It seems as if maybe you do have a problem in the heat exchanger. Maybe the gas/air mix is off and you are getting feathery yellow flame, which is wrong and inefficient.... that type of flame also soots up the exchanger, so this could all be related. Might be that the air shutters on the burners are maladjusted, and have sooted the exchanger, blocking it..

        I think you probably need to check it out, either yourself, or a furnace repair person.

        2801 3147 6749 8779 4900 4900 4900

        Keep eye on ball.
        Hashim Khan


        It's just a box of rain, I don't know who put it there.

        Comment


        • #19
          Could have a cracked or rusted out heat exchanger, gas valve opens, burner fires and then blower comes on blowing air out the cracks in the heat exchanger. I have worked in the HVAC/R field for the past 30 - 40 years or so and surprised at so many of those old 40- 60% furnaces are still out there.

          I had a Lennox pulse furnace that was in this house 30 years ago and then replaced with a Trane 96%, ECM motor and two stage gas valve in 2007. Blower runs on low speed 24/7/365 and has been since 2007. Gas and electric bills are the lowest in the neighborhood.
          Last edited by wmgeorge; 02-11-2021, 06:55 PM.
          Retired - Journeyman Refrigeration Pipefitter - Master Electrician - Fine Line Automation CNC 4x4 Router

          Comment


          • #20
            I worked for the natural gas supplier in Minneapolis about 40 years ago. One of my jobs was replacing faulty flues. On the furnaces prevalent then if the flue was obstructed there would be a stratospheric rise in the home's humidity. In the old neighborhoods in the homes with flue problems the windows would be heavily frosted or streaming with condensation. The old houses had no insulation and were very drafty.
            Back then CO detectors were rare. Asphyxiation usually occurred in homes that were really air tight and featured a fireplace/wood burning stove. The fireplace when burning could cause a negative pressure and cause the furnace flue to flow in reverse. Reburning the flue products causes the CO2 to be converted to CO and hence possibly fatal. A properly working gas appliance produces only CO2 and water vapor.
            That box on old appliances is called a draft/mixing hood. It's purpose is to lower the temperature of the flue products.

            Larry on Lake Superior

            Comment


            • #21
              When a old 40-60% gas furnace back-drafts its dumping CO or Carbon Monoxide out into the house. Yes even wood burners can create the stuff. The draft hood on a furnace was there in part to cool the flue gases but primary purpose to keep the pilot light from being blown out by back drafts.

              A lot of those old masonry chimneys were not lined and the bricks never got hot enough for a proper draw, plus the gas products of combustion would eat the lime out of the mortar and masonry chimneys would collapse or fail. Need to be lined with B vent.

              A properly adjusted gas burner creates CO at 10 or less, you can not do that by eye. You need to test we aimed for 7-8 or even less. Not % Parts per Million!!!
              Last edited by wmgeorge; 02-11-2021, 07:14 PM.
              Retired - Journeyman Refrigeration Pipefitter - Master Electrician - Fine Line Automation CNC 4x4 Router

              Comment


              • #22
                With a small scope that will work off a phone or laptop it should be easy to get a quick look at the inside of a basic furnace. I used to just use a small mirror on a stick with a flashlight.

                Comment


                • #23
                  Originally posted by wmgeorge View Post
                  .......... The draft hood on a furnace was there in part to cool the flue gases but primary purpose to keep the pilot light from being blown out by back drafts.
                  Yes, and it works. It should totally prevent "a few flames licking out of the burner compartment".

                  In 40 years of owning a house with two gas furnaces, I have NEVER ONCE seen that. And I do the routine maintenance, and keep an eye on the thing, it's right in the shop area.

                  If the burners are working correctly, there should be fairly tight blue flame, that simply will NOT get blown back and "lick out" in a normal properly working and properly installed furnace. The fact that the flame deal was even mentioned tells me there is something very wrong with that furnace.

                  I do not know if the burners are adjusted wrong (probably true), the exchanger is blocked (very possible) or what. Possibly both are the case.

                  It sounds wrong enough to need to get it fixed TODAY, this morning.......get on the damn 'phone.
                  Last edited by J Tiers; 02-12-2021, 11:50 AM.
                  2801 3147 6749 8779 4900 4900 4900

                  Keep eye on ball.
                  Hashim Khan


                  It's just a box of rain, I don't know who put it there.

                  Comment


                  • #24
                    Today I got the chance to re-build the furnace. I say re-build because I had it so far apart, including the flue system. One side of the heat exchanger was choked with carbon, the other two channels were mostly clear. I spend hours clearing that up, scraping, blowing, vacuuming- cleaning out the vacuum cleaner. Everything got attention, the burner tubes, air adjustments, heat exchanger, flue fan housing, fan blades, the air flow vane, the flue system including the elbows. I adjusted the air intakes for the burners and got a nice consistent blue flame. Now there is no flame rollout at all, and it seems to be heating more strongly. There never was a smell coming from the vents, and there isn't now- otherwise I would have kept the thing shut down and used electric heaters until a new furnace came. The smell that I had was probably because of the flame rollout.

                    There was something in the flue which came out. Not a bird nest or anything like that- probably build-ups of oxides which broke into sand as it fell out. A lot of that came out.

                    Now I want to 'air-tight' the flue junctions cuz I'm sure by now they aren't sealing very well. I used duct tape where the flue never gets hot enough that I can't hold my hand on it steadily. The hotter areas, particularly right at the exhaust fan box, should probably be done. Not sure what to use there- furnace cement? I do want to be able to get it apart for cleaning on occasion.

                    Now here's another complication which might have affected things- the air conditioner. This is a whole house unit, with the heat exchanger mounted on top of the furnace. It works, but I have to babysit it. If I just let it operate, it will freeze up. It takes about three hours to begin delivering condensate out the drain, so I think it probably wasn't installed right to begin with. Water must be building up in it to some level before it reaches the exit tube- and that can't be good. For the three days on average per year that I use it- perhaps I'm better off to get rid of it entirely. Why have a tray of water sitting there growing who knows what in it-
                    I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

                    Comment


                    • #25
                      Originally posted by darryl View Post
                      Now I want to 'air-tight' the flue junctions cuz I'm sure by now they aren't sealing very well. I used duct tape where the flue never gets hot enough that I can't hold my hand on it steadily. The hotter areas, particularly right at the exhaust fan box, should probably be done. Not sure what to use there- furnace cement? I do want to be able to get it apart for cleaning on occasion.
                      Problem with duct tape is that it dries out, even if it doesn't get really hot. Metallized flue tape is what you want - both for the warm areas and the hot areas.

                      As usual, 3M has exactly the right product: https://www.amazon.com/3M-High-Tempe.../dp/B00004Z4DS


                      -js
                      There are no stupid questions. But there are lots of stupid answers. This is the internet.

                      Location: SF Bay Area

                      Comment


                      • #26
                        Originally posted by darryl View Post

                        darryl started a topic dead furnace
                        For real? Are you not up North in the greater cold part of the Earth?

                        I thought fire starting was in the first class so you can cook and stay warms?

                        Hahaaha. Sorry, just had to get a chuckle.

                        My advice, look for a really nice wood stove and a nice supply of dead fallen trees. You might make it, JR
                        My old yahoo group. Bridgeport Mill Group

                        https://groups.yahoo.com/neo/groups/...port_mill/info

                        Comment


                        • #27
                          Sounds pretty much as I expected.... your burners were probably maladjusted with a long dirty flame that blocked the exchanger with soot. Good that you got that taken care of.

                          If you got a lot of oxidation out of the exchanger, you may want to be really sure it does not have any leaks to the hot air side. Most are made of relatively thin metal, and any large amount of rusty gunk had to come from somewhere. The metal on most is not thick enough to stand much corrosion before it starts to get leaks.

                          Also check that the burner outlets are clear. The adjustment needs to be done with clear flow. Blocked flow can mess with the mixture and the result may be another change in the flame type later.

                          The stuff could of course be from another source. We cannot see it. You will need to judge if it is corrosion product from the exchanger.

                          Someone commented that the real way to adjust the air shutters is with a CO meter. That is correct. Guessing at the flame color and shape is not a guarantee of anything. So if you had an undetected flue gas leak, you want as little CO as possible, and may want to get it checked out.
                          2801 3147 6749 8779 4900 4900 4900

                          Keep eye on ball.
                          Hashim Khan


                          It's just a box of rain, I don't know who put it there.

                          Comment


                          • #28
                            If it's freezing up you may be low on freon.

                            Comment


                            • #29
                              I'm chuckling too. Lately I have been thinking how it would be to live in a cabin in the woods, keep a wood fire for heat and cooking, have my own power systems, etc. I could do it. Anytime I mention it to friends, they say NO, DON'T DO IT, we'll never see you again. Fair enough, I do love my friends.

                              Right now through this furnace problem, it seems that this happened in the coldest time of our winter. I do live in Canada, but I don't live in the great white north. It's cold enough regardless, and windy too. And tomorrow it's supposed to snow, and wouldn't you know it, it's the day I have to make a trip into the city to see about mastering the collection of songs we've been working on. But whatever- you do what you have to do. I'm not worried about the snow, I'm worried about the people on the road-

                              I can't say I've mastered fire starting, but I'm pretty good with it. Fire (controlled fire) is so relaxing to me. I have a wood stove- but I can't use it because the chimney started leaning towards the street and I had to take it down. My insurance company does its best to discourage the use of wood stoves- and I just decided to forget about rebuilding the chimney. I've told my friend the producer that when we build the new studio (where I'm hoping to have my shop and modest living quarters) it's going to have a fire pit in it. I might have to settle for a gas fake fire, but that's ok.

                              I'll make it, JR, don't worry about me

                              As far as the air conditioner- if I end up replacing the furnace, I'll probably take the air conditioner out. As I said, I use it about 3 days of the year, so it's not really worth the hassle. I'd just get a window unit if I really needed it.

                              And I do plan on having someone over to check out the furnace in the next few days. At least now I can sleep at night, knowing I'm not going to be gassed. If the thing is on its way out, well, I'll do what I have to do- on a warmer day.
                              Last edited by darryl; 02-13-2021, 03:16 AM.
                              I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

                              Comment


                              • #30
                                Originally posted by darryl View Post
                                I'm chuckling too. Lately I have been thinking how it would be to live in a cabin in the woods, keep a wood fire for heat and cooking, have my own power systems, etc. I could do it. Anytime I mention it to friends, they say NO, DON'T DO IT, we'll never see you again. Fair enough, I do love my friends.

                                Right now through this furnace problem, it seems that this happened in the coldest time of our winter. I do live in Canada, but I don't live in the great white north. It's cold enough regardless, and windy too. And tomorrow it's supposed to snow, and wouldn't you know it, it's the day I have to make a trip into the city to see about mastering the collection of songs we've been working on. But whatever- you do what you have to do. I'm not worried about the snow, I'm worried about the people on the road-

                                I can't say I've mastered fire starting, but I'm pretty good with it. Fire (controlled fire) is so relaxing to me. I have a wood stove- but I can't use it because the chimney started leaning towards the street and I had to take it down. My insurance company does its best to discourage the use of wood stoves- and I just decided to forget about rebuilding the chimney. I've told my friend the producer that when we build the new studio (where I'm hoping to have my shop and modest living quarters) it's going to have a fire pit in it. I might have to settle for a gas fake fire, but that's ok.

                                I'll make it, JR, don't worry about me
                                Not me, I dont worry about you Mr.

                                I just want a taste of this music you speak of? JR
                                My old yahoo group. Bridgeport Mill Group

                                https://groups.yahoo.com/neo/groups/...port_mill/info

                                Comment

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