Anyone with furnace experience?

Discussion in 'Shop Talk' started by Peace n Quiet, Oct 16, 2006.

  1. Peace n Quiet

    Peace n Quiet Well-Known Member Supporter

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    Our furnace has decided to retire. :( Now, we've called two local repair guys with good reputations, but they haven't even taken the time to call back to set up an appointment even though I've called each one 2-3 times over the last 4 weeks. :shrug: Seems they are still busy installing new furnaces to all the homes affected by the flood in June. So, DH has tried to diagnose/repair the thing himself and he's concluded that it's probably a cracked combustion chamber.
    Now, can anyone give me the bad news? My google search didn't tell me what I need to know... what's the cost of a new oil forced hot air furnace for a 1000 sq ft two story house?
     
  2. ericjeeper

    ericjeeper Well-Known Member

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    heating units are rarely sold to homeowners
     

  3. Ross

    Ross Moderator Staff Member Supporter

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    Combustion chambers can be replaced (if the rest of the furnace is worth it) for $200-400. Heat exchangers can be changed too but you may as well buy a new furnace if its older than 9 yrs. Retail cost of a furnace in Cnd$ is around $2500 and up for something 75,000 btu to 95,000 btu Can be more too. I'm installing a bigger furnace tomorrow with a chimney liner that will run just under $5k including labour and taxes.
     
  4. Ross

    Ross Moderator Staff Member Supporter

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    Oh and Eric is correct you probably need a license to buy a furnace. You won't get it set up very well unless you have alot of experience or a smoke tester and an analyser anyhow.
     
  5. mtman

    mtman Well-Known Member

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    try ac direct.com they will sell to you
     
  6. Peace n Quiet

    Peace n Quiet Well-Known Member Supporter

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    Thanks, our furnace was here when we bought the house nine years ago. We figure it's about 15 years old.
    I just got off the phone with DH. He thinks we should look at outdoor wood burners to replace our system. I can think of at least three local dealers, but only one installs the units himself. The rest use sub contractors.
    I guess it will come down to cost. Doesn't everything?
     
  7. Stillponds

    Stillponds Active Member

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  8. Ross

    Ross Moderator Staff Member Supporter

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    Gas stuff is cheap, stamped tin exchangers and simple burners, the high eff. condencing jobbies are terrific in gas but still dodgey in oil. Careful of those really cheap gas furnace prices, be sure they include all the required safty switches. Each item like a vent provign switch etc. costs at least $50. Of course you can save thousands, if you don't buy the skilled use of tools or installers insurance but you may lose you warrenty, and your home owners insurance. Law here says you CAN DIY but it must be to code.
     
  9. joken

    joken Well-Known Member

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    Where do you live?
     
  10. Gideon

    Gideon Well-Known Member

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    Where do you live-anywhere close to NC? If so drop me an E. Have a good furnace for the giving. Not new but free,wc
    Edited to add--If you are not getting smoke through the vents your phelem(?)(heat exchanger) and firebox is not leaking. What is it doing? Or not doing? Does it try to come on? Can you hear the pump running? Can you hear it ignite?
    If the pump is running for a short time(@20 seconds)and cutting off then the either the points are not properly spaced or not firing(transformer may be bad or just need the contacts cleaned). Be SURE the switch is off when messing with the transformer. It will give you an instant afro hairdo and make your shoes smoke-lol. The points can be adjusted by loosening the screws and sliding them out slightly. If necessary bend them in to about a nickels width about 1/3 inch ahead of the nozzle.
    If the nozzle is not spraying a very fine mist then replace it with the same flow/angle.
    Furnaces are not complicated and if you do have to replace it the process is not hard. Unhook the ducts(usually with sheet metal screws) and inlet. Loosen the fuel line(after cutting off the valve at the tank). Disconnect the electric line(after cutting power and checking with tester) and the thermostat wire(little red and white braided wire). It is ready to remove from under your home and replace. wc
     
  11. Ross

    Ross Moderator Staff Member Supporter

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    Gideon describes one or two conditons where the furnace doesn't start, there's plenty more. No they're not extremely complicated (mostly) but getting it wrong can have disasterous results. Please remember if the pump is running and there's oil getting through the nozzle, you are loading the chamber with oil. Get enough in there and get it warm enough to vapourize and it is explosive if your ignition problem suddenly corrects its self. You might not be getting any fuel, a plugged filtre or kinked line, a blocked nozzle, or a failing pump or pump drive, heck the Z adjust could be out of whack and it's finnally blocked the whole works! Simple Furnaces are also getting more complicated most have extra safety switches added like a blocked vent switch, or have oil valves that allow a pre purge of the vent air to establish draft and do not even try to start the flame for a preset time as a normal condition!!! One of the more fickle parts on a furnace is the CAD cell. Again not a complicated component to trouble shoot but even when its the problem its not always the problem! Just having a dirty blast tube or static disc can throw a CAD cell. Just be careful.
     
  12. Peace n Quiet

    Peace n Quiet Well-Known Member Supporter

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    You all are so helpful! Thank you very much. :)
    I'll do my best to explain further, but I'm not the one who worked on it so I hope I tell it right!
    The transformer is relatively new-less than a year old. The nozzle is new & correct. The pump is less than five years old. Full tank of oil - filled after the problem started.
    What it's doing is this: It starts up, runs, and shuts off just fine. But, it smells like fuel (To DH, to me it smells like burning plastic) from the ductwork/registers, we haven't let it run long enough (more than a minute) to see if smoke also comes through the ducts.
    DH called around yesterday. A new unit, comparable to ours is around $1300. Installed our estimates ran from $3200 to $3600. We questioned the difference and was told by one guy that the installed price includes replacement of flue, fuel line, and any ductwork needed to connect the new unit.
    Now, my question is this... DH is a very skilled auto mechanic. Very handy guy who pays attention and is very meticulous. Is it illogical to think that this is a job he can handle on his own? (with informed direction of course) If yes, what should he watch out for?
     
  13. Ross

    Ross Moderator Staff Member Supporter

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    The grunt work, chuck the old one and place the new one? Too easy buy beer invite friends. Duct work or build downs, does he like sheet metal work? It's not overly difficult. Running a chimney liner? They go from painless to foreign language swearing, (I'll wager you need one) and it has to be installed to code. All clearances should be in the manual. Double check that though. In Ontario its code to run a new fuel line with any new install. I imagine your code is similar, it must be the coated fuel line here, I expect it's the same there. I take it he can flare copper tubing? (its easier than brake lines so I hope so) Remember no compression fittings, anywhere, ever! Draft regulator is installed two flue diameter width measures away from the breach, (its not gospel but at least that and not much more) and don't buy a cheap one. Its not included in your price, neither is new C vent and elbows. Think $50 for a good regulator and about $50 for C vent unless its a long haul (double wall over 20 feet here). Get 26 guage galvanised not duct work 30 guage. You likely need a combustion air vent/duct system, I doubt either installed price includes one. Again they're brainless to install. Actually I'm curious if your price includes a burner, even converting currency its unsettlingly cheap at 1300 USD. What make? Ok if it does what burner is on it? A Beckett AFG? or Riello? Aero or??? Here's where you run into trouble. Your hubby won't have the analysers or the other tools/skills to check things like the z adjustment or pump pressure or a multitude of other things, setup draft etc, and test a new installation to be in code for temperature rise etc. etc. etc. And vent sizing has to be to code, lots of old stuff is far too big. There should be a blocked vent switch to install, to lock out the burner if the vent blocks up with a birds nest or whatever. That said the testing part could be hired for 2-3 hours labour (I'd guess)

    Leaky heat exchangers often leave a metallic taste in the back of your throat from aldehyde's given off from poor combustion, and it also indicates a poor chimney, if it was working well you might not even get combustion fumes in the house for a while. Plastic smells are often plastic that's made it into the duct system........ maybe you don't need a furnace after all! Is the blower fan motor going through terminal melt down? They smell like plastic burning. So could a rubbing belt, blown bearing, chaffed electrical line, an air filter flipped up onto the vent pipe, or mashed into the blower fan belt...........
     
  14. Ross

    Ross Moderator Staff Member Supporter

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    BTW do you have an electronic air cleaner or humidifier on the furnace ? Two very probably sources for smells.
     
  15. Ross

    Ross Moderator Staff Member Supporter

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    Come to that (Its been a looooonnnnggg week) is your duct work hooked up to an HRV, or do you have an A coil?
     
  16. Ross

    Ross Moderator Staff Member Supporter

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    How about a cold air return off your cold air supply plenum? Or something in your basement that is creating the smell?
     
  17. mdharris68

    mdharris68 Well-Known Member

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    Now let's not jump the gun here.

    Wouldn't it be prudent to test the supply air for carbon monoxide first to determine if there is a cracked heat exchanger? It could be as simple as calling your fire dept and asking them to check for c.o..

    I have only worked on one oil furnace in 10 years but I would think that if there is no carbon monoxide, that there may be no need to change the furnace.

    Also remove whatever ductwork is necessary to reveal the heat exchanger and inspect for cracks. The smell could be a piece of plastic that has made it past your filter, through the blower vanes and near the bottom side of the heat exchanger. (assuming that you have forced air heat.)

    I would also pull the blower and look at the heat exchanger to see what may be there.

    The smell of plastic burning could be from a secondary transformer or your motor windings going out. Take a good look at all these things if possible, before changing your furnace based on guesses.
     
  18. ovendoctor

    ovendoctor north of the lift bridge

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    good idea checking for CO

    Iworked on a furnace for a family friend
    the hot surface igniter was cracted and they had not run it for a year
    got it running but also found the missing hamsters
    they got in the duct work and ended up on the heat exchanger :baby04:
     
  19. mdharris68

    mdharris68 Well-Known Member

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    I once pulled a blower and found the family menagerie; trantula, salamander, and a mouse all together. I think it was a planned thing they all met there to say goodbye. :baby04:
     
  20. Ross

    Ross Moderator Staff Member Supporter

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    Testing for CO while not a bad idea is not conclusive either. Naturally you'd compare ambient levels of CO before hand and compare them to what's in the supply plenum and sure elevated CO would likely be from a cracked exchanger but no CO is not a clean bill of health at all. Several reasons. Most oil fired furnaces are negative draft, meaning they'd actually suck air in to the exchanger through a crack and would only leak CO if the vent were plugged, or the chimney back drafted. Using a combustion analyser you could measure excess air getting in. The other thing is not all furnaces will emit measurable CO, if they are set up right, you can often get 0 ppm CO, still if the air band or shutter gets bumped or the chimeny fails then that setting is messed with and you get CO. A good qualified examination is where to start and a smoke test (with a smoke bomb or capsule) would show (or smell ) out the crack. That plus the analyser looking for too much excess air is the way to do it. Just testing for CO can give a false pass.