No heat/air movement anymore in one room, 'tinking' noise repeating

Discussion in 'HVAC Heating & Cooling' started by GregN31, Feb 23, 2010.

  1. GregN31

    GregN31 New Member

    Messages:
    14
    Location:
    South Dakota
    I have a split level home. Our furnace is in the basement. Lennox two-stage high efficiency furnace with variable speed blower. The duct work runs between floors. There is a 3 foot high or so 'void' between floors where the duct work runs. The main line (if thats what you call it) runs the length of the house right down the middle essentially. There is a unfinished part in our utility room where I can get up and see a lot of the duct runs. It appears that the duct work simply branches off left and right to various rooms. It either goes up to the upper floor where we have registers in the floor of the rooms or down to the ceiling for the basement rooms. Starting sometime recently air flow has stopped in one room in the basement. We do not have zones, it is a single thermostat with no zoning. As far as I know there are no dampers to access. In this particular room where the register is, there is no air movement at all, it doesn't even feel warm anymore. In every other room the heat is coming out just fine. The fan is set to ON all the time and you get nothing when the heat is on or when its just air circulating from the blower. I have tried various things. I took the register off and stuck my arm up as far as I could, feel nothing out of the ordinary. This register is on a ceiling in the basement by the way. Used a small mirror that you can extend and a flashlight to get a look up as far as I could. The short distance I can see it looks ok. No obstructions, no obvious disconnection. The adjacent rooms have good powerful output. From what I can tell the main line runs down the center of the house and the adjacent bathroom is right near this center line. That register is fine. Then it takes a left turn and heads into this room. I am guessing it must be this 10-12 foot length that is the area in question.
    My biggest questions are, how do you even repair something like this or determine where the fault is. This is a finished basement and to the extent one can minimize damage to ceilings and sheetrock repair would be nice. Could it be a connection has simply fallen off? I'm no expert but I don't know what else would explain it. I closed all the registers but this one and maybe one other one in the house and I still get no airflow. Its not tepid, its nothing at all. That room is now colder than the rest of course.
    There is one area in the utility room where I can get on a ladder and can get access into that 'void' between the two floors. Would it be totally out there to take a fliashlight, crawl up there and carefully crawl across it to the specific area to try to investigate it that way? It would be a crawl and somewhat tight. I know I'd have to be really careful to crawl from joist to joist and not fall through a ceiling or anything :) I wonder if anyone actually does this. The only hazards are the tight spaces and the wiring running all over the place up and down to the various rooms. Is this a really bad idea? If I can squeeze myself across the house and not fall through the ceiling I might be able to find the answer I'm thinking. How would a pro do this? My ideas, although I don't have the equipment would be maybe you could put a camera through ductwork to see where it seems to break, like they do with sewer lines. Or perhaps a thermal sensor, since I am pretty sure I know where the duct work runs across the ceiling if there is a break I would assume when the heat is on the temperature on the ceiling where the break is should be quite a bit warmer than anywhere else, and that would at least tell you where to cut approximately?

    My other big annoyance is right in that area we have a 'tink' noise. Its loud and metallic sounding. It may have nothing to do with this problem. It is almost inaudible in the room with no heat/air. The room above that room is our master bedroom and its really loud there. Its VERY annoying. It starts typically after the heat has been on and then turned off and continues for quite a while after. Then it stops, then the heat comes on again, and after the heat is on or finishes heating it starts again. Its a metallic tink noise say every 15-30 seconds over and over. I am guessing a piece of ductwork is expanding and clanking against something. Perhaps a crawl across the house might help me figure that out. This would be a pretty tight squeeze, but might be the best way to do this in our finished house.
    There are cross members running across the house so I'd have to crawl over through those on the way across the house. So it wouldn't be any easy crawl, but I think I could pull it off. I wouldn't do it if I were claustrophobic. I just don't know if anyone actually does this.
    Any ideas on either problem, and if anyone actually uses an exposed access in a finsihed split level to start crawling around? As I said there are the wires, the cross members, and of course all the copper supply pipes running all over. I would have to watch for all of those. I'm no contractor or specialist, so maybe its a dumb idea all around. I figured though if it worked it would be awesome. If I can get over there and get a look maybe I'll see something painfully obvious like a connection fallen off because it wasn't done well originally and just happened to finally fall off, and perhaps I will hear the 'tink' noise really loud and will be able to use insulation or whatever to quiet down whatever is making the noise that keeps me aggrevated in the dead of night.
    Thanks.
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,804
    Location:
    New England
    The hassle is could you turn around once you crawled through that mess! I think a camera might be the best solution to try to see what's up. Once you've identified where it is, then you could cut into the ceiling or decide if you could fix it another way. Another thing, once you crawled up there, would have have the tools you needed to fix it? It would be a pain to have to do it multiple times! An IR thermometer might help isolate the area, but it would be iffy. If you had one, or could borrow one, it might lead you to the right area.
  3. colo

    colo New Member

    Messages:
    3
    Location:
    Colorado
    We are having the exact same problem.. no heat to one downstairs room, all others next to it fine. AND the tinkling noise. Any thoughts or suggestions on working it? We had someone come out before and they said they fixed it but nothing is different.
  4. colo

    colo New Member

    Messages:
    3
    Location:
    Colorado
    We are having the exact same problem.. no heat to one downstairs room, all others next to it fine. AND the tinkling noise. Any thoughts or suggestions on working it? We had someone come out before and they said they fixed it but nothing is different.
  5. GregN31

    GregN31 New Member

    Messages:
    14
    Location:
    South Dakota
    Sorry to hear that. We still have the issue. I was just thinking about this problem again and I'm going to call a few places in town that do duct cleaning service. They have cameras they put into ducts to demonstrate how dirty they are. I don't know how long they are but it seems to me its the best shot at trying to determine if something has come loose. A contractor gave me a useful idea too. I was thinking of having someone tear my finished ceiling out in my basement bedroom. He told me I should instead go to the room above, have the carpet pulled back, they can cut the subfloor and take a look. Then you could repair subfloor and put the carpet back. Should be a lot less mess and repair then destroying a textured ceiling. In any event we need to try to find where the break or issue is before you start blindly tearing up/cutting into ceilings/floors.
    The only other side note is another contractor told me that the 'tinking' noise that we hear is just from the expansion/contraction of the duct work when its cooling down after the furnace runs and completely normal. Whether that is true, I have no idea. But its annoying in the dead of night.
  6. colo

    colo New Member

    Messages:
    3
    Location:
    Colorado
    We did have the furnace guy come out and look at our tinkling noise. One of them thought I was nuts, the other one found where the duct work was hitting against a beam and nail when it would expand and contract and he cut some of the beam away as well as he could without damaging the duct work, it was right against each other. HUGE improvement, but not perfect. But, enough to live with as before it was enough to make you crazy. It did help. I did think about the duct cleaning first and I like that idea. Had them do it before but didn't mention the problem or ask about it. Probably need to choose a professional heating company that does it and not just someone that operates the machine and knows nothing about heating and ask them to keep a look out. Good Idea, thank you.
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,804
    Location:
    New England
    Pretty much everything in nature expands and contracts with changes in temperature. This isn't a problem unless the material that is changing dimensions is anchored and rubs against something while it is trying to expand or contract. This happens a lot with plastic drain pipes and can happen with metal ductwork. The duct must be built with this dimensional change in mind. Normally, the things are fairly loose, and it isn't a problem, but get it tight somewhere, it certainly can be.

    WRT the room without any air movement, it could be that the duct became disconnected. I had one that did that (really poor workmanship) in one of my upstairs bedrooms. There was a flexible duct that fell off the distribution box and was spewing conditioned air into the attic. If the thing is put together properly, that can't really happen, but out of sight, you never know.
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