Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Chimney Liner Issues

D107 Member Posts: 1,798
edited July 2017 in Oil Heating
2006 oil-fired Buderus G115-21, Riello 40 F3. 5 inch, 22ft 316UL smooth chimney liner. Had certified chimney sweep inspect it last week--after no cleanings for a few years. Liner itself doesn't look too bad, but sweep noticed:

1) no tee-cap at bottom (original cleanout box was not bricked up, which apparently runs the risk of air infiltration);

2) Felt that they did not insulate with thermix, as per contract. Photos seem to show thermix at bottom but at top at least in the one corner visible seems to be none, or it settled.

3) I'm also not clear if the top photos show whether it's smooth wall or not, which is supposed to be much better for draft. (This is a 7 inch clay liner the metal one is fitting inside of.) When he opened up the breeching piping he found a handful of white dust and said that was due to condensation. In my layman view that little dust after maybe four years of not being cleaned does not signify a huge amount. He wanted to put a new liner and insulation in.

4) My thought is since the original install had a lifetime warranty, I'd want the original company to insulate if they didn't, put smooth wall if they didn't--unless the flue is not straight and they need to make bends in the liner; and put a tee-cap in to make it legal. Even though we did alot of research at the time it's upsetting that some things may have not been done properly; and after the job is done one assumes it was done right, since not everything is that easy to inspect. I intend to call another sweep for a second opinion, open up the top and get a good look--with photos--to see about the insulation.

5) Also, apparently having galvanized breeching piping is ok leading up to the horizontal Tee connection, but it sure looks like 6 inch diameter to me, though the liner itself is 5inch.

6) The photos will show the original breeching piping which had a cleanout, but because there were too many 90 bends they changed it to the new setup some years ago, which doesn't have a cleanout. So if they put in a tee-cap then somehow there will have to be a cleanout created.


  • STEVEusaPA
    STEVEusaPA Member Posts: 5,688
    I didn't really see any questions. But:
    -The new way is better (although ugly) than the old way. Less 90° elbows equal more draft.
    -Insulation could've settled a little.
    -4 years is not recommended interval for a cleaning.
    -The chimney connector (pipe from unit to chimney base/connection-in your case the liner) cannot be reduced by code, so it's ok.
    -I don't know why you thought you needed the liner swept. And I really don't trust the sweep telling you that you need a new liner.
    -The whole chimney connector pipe should be removed and cleaned during a boiler cleaning, and the base of the liner can be cleaned if needed-so forget about a cleanout tee. Not needed and could create draft problems.
    -Some white powder could indicate it's underfired, not enough draft and/or low stack temperatures-can be checked/confirmed/fixed by your oil tech.
    -I would raise all your chimney concerns to the original installer.
    -If the person servicing your boiler does annual maintenance, and the combustion and draft are properly checked, AND it's running at it's proper and peak efficiency, I wouldn't worry about it.
    -I don't trust this chimney sweep.
    -If you have no draft problems I wouldn't worry about smooth wall (your liner isn't smooth wall).
    -I'm assuming there's a cap on top, judging by the silicone.
  • Big Ed_4
    Big Ed_4 Member Posts: 1,882
    A Flexi-liner 5" with an 15' chimney with 2' single wall hozontal run can support an single 119,000 BTU appliance .. I think your boiler is 85K with an 5" smoke pipe .. Higher the chimney, the more the liner can handle in BTU's.. The vertical smoke pipe adds to the chimney as far as hight ..

    The ash is not an sign of condensing , its more of sulfur residue from the oil .. It may be an good sign chimney seems warm enough and not condensing inside .. If you found crystallized sulfur , I would be concern of condensing or lack of an proper rain cap.. In the cold weather when system is running you will see vapor or condensate leaving the chimney. If there is an space between the vapor and chimney your good .. Your Buderus is equipped with adjustable baffles to adjust stack temperature if need be ... Proper stack temp look between 270*to 370* above air intake temperature .. Say your drawing air in from an basement at 60* You want to see at the breach 330* -430* .. I feel safer above 350* .. 50* either way is an 1% difference in efficiency

    I would cap the clean out or extend it down with a cap to satisfy the code and easier to clean it out ..

    I guess the second setup is an little better with a sweep.. I don't think it was a big issue. . The original set up he was thinking of service using the cap on the run for cleaning which I like .. I guess an sweep of an ell is better then an bull. .. First job does look neater ..
    Is there any issues with draft ? Its an outside chimney that will get cold more quickly, insulation is important ... North West facing chimneys are the worst .. I seen in the past an lack of draft for a few seconds until the liner heated up ..

    I have enough experience to know , that I dont know it all
  • D107
    D107 Member Posts: 1,798
    @Big Ed and Steve: Thanks.
    No draft issues as far as I know; usual stack temp is 275-300, been that way for years. We haven't removed any baffles. Oil Co doesn't have digital equipment so I get an outside guy with an analyzer in every few years. This is just the state of things out here.
    ––I have always been told that chimney liners should be swept or cleaned with those nylon brushes every year to remove any dirt that might adhere to the walls. I have our oil company vacuum out the boiler fireside and connector piping every year, but usually not as far as pulling the chimney connector pipe which we've left to the chimney guys. Hopefully if it's done right it won't be necessary to re-cement the wall around the penetration every time it's pulled.

    ––My notes from a few years ago from a very knowledgeable chimney sweep about the tee-cap at the bottom: "To properly install the lining system the tee cap must be installed (riveted)on the two part tee. If it wasn't, air would dilute the draft and the chimney system and appliance won't perform properly. The liner manufacturers warranty states that the system must be swept annually."

    At the very least I should ensure that the bottom cleanout is tightly sealed. If we put the tee-cap on, I guess the liner bottom can be cleaned when the chimney piping is pulled, and most of the breeching piping debris is accessible via vacuuming through the boiler and into the piping up to the first 90 turn, which should do it.

    This is an outside chimney and does face northwest. Yes there is a chimney cap, see photos.

    HVACNUT Member Posts: 4,590
    What your referring to I think is the "drop tee" inside the chimney. On the vertical run sides, the top connects to the liner, and the bottom is open? If that's the case, then the open end should be capped, even if the original chimney is supposedly sealed.
    The G115 specs. 0 just positive over fire and -02 breach. If you're getting that, then I wouldn't stress about it even though it should've been done originally. It'll be a job to pull the liner just to cap the drop tee.
    Oh, and throw away the phone number to the guy who tried to sell you a new liner.
  • D107
    D107 Member Posts: 1,798
    I've been told the tee-cap can be installed on existing liner bottom--maybe they use hi-temp adhesive instead of rivets and push it up into place. I wouldn't pay to pull and redo the liner--and tee cap-- unless it turns out thermix wasn't done properly in which case i'll get in touch with original chimney company re: warranty.