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chimney relining?

Hi guys,

I have one chimney with one flue inside. Clay lined. 1930's vintage. I have (2) gas steam boilers and (2) gas hot water heaters dumping into this chimney. Probably a total of 300,000ish btus

One of the boilers needs to be replaced. With the assistance of Tim C, I've found someone reputable to replace it. This contractor asked me to get the chimney inspected before we went any further.

Of course, the chimney sweep discovered that the chimney needed to be relined, the top needed to be rebuilt, every part of it needed help and work, and the total would be something like $4,500 and do I also want my gutters cleaned because they are really dirty?

Now, my bulls**t detector has gone off at that last thing, because I just had the gutters cleaned. A few of his other recommendations seemed a bit suspicious as well.

So, this has left me wondering if the chimney needs to be lined. I had a mason come today to give me a quote on fixing the top of the chimney (a bit of repointing and a bit of rebuilding - the masons' quote is half what the chimney sweep wanted for the same work...) The mason thought that the very top course of the clay liner would need to be replaced, but only because he'd have to redo the brick around it.

Can you guys tell me why I'd need the chimney relined? I know if it's cracked that it can let carbon monoxide into the house. What I don't know is if there are other reasons, for example would the size of the chimney (it's an 8" x 12" clay flue) matter for the equipment that's using it? I'm hoping to install a smith series 8 with the gas gun (wet base boiler), so maybe the higher efficiency boiler would require a smaller flue?

I'm planning on getting a second opinion and get someone to run a camera down the flue, so I can see for myself what's wrong with it. The inspector who came this time showed me a blurry photo of a flue and told me it proved I needed a reline. I don't even know if it's my flue!


  • Boiler Talk
    Boiler Talk Member Posts: 136
    New boiler, new liner

    My chimney is straight, so you could stick mirror inside and look up.  It had no liner.  I had at least 150,000 btu's added - water heater and oil steam boiler.  I bought a 25' - 30' 6" stainless steel liner.  I was told the equipment determines the liner.  Carbon monoxide is the problem.  The cost for the liner was about $1900, if I remember correctly.  This is NJ.  Your chimney needs to be certified.  The key word is certified. 
  • Bio
    Bio Member Posts: 278
    Power venting

    Burnham also offers power vented boilers with the IN series I think is call PVIN, check their brochure This way you vent on the side of the house and may be have a higher AUFE
  • conversiontime
    conversiontime Member Posts: 87
    2 different issues

    Could be two different issues but in the end they relate. A clay liner is better than raw brick/mortar but a stainless steel liner is ideal. The reason is NG vapor exhaust can be very wet/acidic which eats up unlined chimneys and even clay liner over time. So the ideal is to use ss liner and size is determined by equipment, run length, etc. That much BTU and two units may require separate liners.

    The chimney could very well need rebuilding aside from the liner. Old brick chimneys generally need regular preventative maintenance to avoid more drastic rebuilds. A experienced chimney mason is who you want, like many professionals the best are busy and are paid accordingly. I personally had my clay lined and in good shape chimney relined with ss when converting to gas even though not required as I believe it will save money in longer view. Some areas have stricter coding than others of course.
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