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PF100 Smoke Smell

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Ejectr, Oct 28, 2011.

  1. Ejectr

    Ejectr Minister of Fire

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    I have a newly installed Harman PF100. Since starting to use it last weekend, I have a very noticeable smoke smell coming out of the forced hot air heat supply vents in my house. can't see smoke but can smell it all the time if the blower motor is supplying heat to the house.

    All vent pipe seams are selaed with metal tape and the adapter to the exhaust nipple on the furnace is sealed with high temp silicon. I did notice the fire compartment door latch at the top seems to have more grab than the bottom. Could the door seal possibly be leaking by and letting smoke into the hot air supply side somehow? The fire is not lazy at all, but is straight up, not slanted toward the heat exchanger accordion tubes.

    Any suggestions are appreciated.

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  2. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    How did you seal up the return air system?

    On the exhaust side you can look using a strong light in a dark room when the furnace first fires up, shine the light all along the exhaust side from the air inlet of the combustion blower to the annulus around the pipe exiting the house. Pay particular attention to the stove adapter and any tees.
  3. Ejectr

    Ejectr Minister of Fire

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    The return air was installed by the HVAC guy. I have the PF100 installed in tandem with my oil furnace duct work that was already there. He connected it into the existing return air duct work from my oil furnace forced hot air system and then to the air box where the air filter is. Should I seal all the seams in the return air as well? I noticed that when i mounted the air box to the furnace, there was a slight gap between the airbox surface and the surface it mounte to on the furnace. I could see light shining through it. Should I seal that as well? My train of thought is if the vent isn't leaking exaust, the return air wouldn't be picking it up, so it has to be something in the venting/exhaust area leaking. Correct?
  4. dmaclaren

    dmaclaren Member

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    I had that on mine too. On mine is the smoke comes around the appliance adapter and goes back into the box area. So, inside and outside around the exhaust pipe fixed it for me
  5. Ejectr

    Ejectr Minister of Fire

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    Do you mean you had to seal both the inside and outside of the adapter? How did you do that?
  6. dmaclaren

    dmaclaren Member

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    Okay, click this link - http://www.hearthnhome.com/downloads/installManuals/PF100.pdf
    Look at the first page. See the exhaust pipe where it goes through the frame. I didn't seal the gap between the pipe and the frame (box) where the pipe goes through.

    Now, the reason it gets into the outside frame box is that the appliance adapters don't fit snug and during start up, there is so much smoke in these units and a natural air movement without the blower on, it causes a little leak between the exhause pipe and appliance adapter and it goes down into the box.

    Once that happens, the blower will then carry it into the home.

    THis year I added caulk on both the outside and inside.

    BEST TESTING METHOD.

    use a spray bottle and do a little mist on a couple handfulls of pellets. Use them to start a cold unit. THis will produce a ton of smoke to see. Find your best flashlight and aim it all around. Sometimes you can't see the smoke unless you have a light. Also, best if you don't have the duck on the top of the unit.

    Hope that helps
  7. Ejectr

    Ejectr Minister of Fire

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    So you sealed between the bottom of the exhaust pipe and the frame where it enters the frame and you also applied sealant to the inside of the adapter before you slid it on the exhaust pipe. Do I have that correct? I've sealed the bottom of the adapter where it meets the frame over the exhaust pipe, but I don't think the installer sealed the inside of the adapter to the exhaust pipe. Thanks for your help with this.
  8. exoilburner

    exoilburner Feeling the Heat

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    Like previously mentioned you need to seal the inside of the PF100s vent connection. The black sheet metal around the PF100 vent connector is not sealed to the connector at the factory. (Harman really dropped the ball here.) Smoke is pulled back into the furnace hot air supply chamber from between the furnace vent connector and the black sheet metal around it. And when the distribution blower kicks on; it sucks even more smoke in. I filled my furnace vent connection with hi temp silicon and it completely stopped all the smoke smell out of the ducts. Just nice clean hot air.
  9. Ejectr

    Ejectr Minister of Fire

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    OK, so now that my vent pipe is installed and the ducting to the hot air supply is installed....how do I seal the inside of the exhaust vent connection? Or better question....before the vent pipe and the hot air duct was connected, how would one seal the inside of the exhaust vent pipe? I know this was not done by the venting installer before the vent pipe was installed. The answer will give me an idea of what I have to disassemble to get at it. Thanks.
  10. Skippydo

    Skippydo New Member

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    Fired up the PF100 this morning.
    When I turned it on, the fan kicked on. I guess when I clened the unit
    I hit the switch on top of the limit control.
    Fired right up, burned off the summers collection of dirt, and heating the house.
    Love the heat, makes me wanta go to bed and have a good nights sleep.
    Good luck to all!!
  11. exoilburner

    exoilburner Feeling the Heat

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    If you are sure the inside of the vent adapter is not sealed with silicone could you cut off the silicone on the outside of the vent pipe connection; remove the vent pipe and seal the inner and outer walls of your vent pipe adapter with hi temp silicone. Or do like I did and completely fill the void between the inner and outer walls of the vent pipe and push it down over the PF100 vent connector. The only draw back when you do this is the vent pipe becomes permanently attached to the furnace. But it did the job. No more smoke out of the ducts. You may not need to remove the sheet metal duct on the top of the furnace if you remove the vent pipe & adapter and apply the silicon to the inner and outer walls of the connection while it is removed. Then push them back on before the silicone sets up. Make sure you use enough silicone so it does not get voids in it when you push the pipe back on the furnace.

    Could you post a picture of the PF100 connection to the vent pipe?

    If the installation is still in warranty it may be better to have the dealer fix this. At least see if they go along with this fix and learn to seal the vent pipe right. They did a really poor job sealing mine.
  12. Ejectr

    Ejectr Minister of Fire

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    Does the sleeve of the adapter that goes on the furnace exhaust pipe seat inside the exhaust pipe's inside diameter or slide over the exhaust pipe's outside diameter? I would hope the vent installation is still under warranty seeing it was done less than a month ago and this is the first time I used the furnace since then.
  13. exoilburner

    exoilburner Feeling the Heat

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    I do not know how an adapter fits on to the PF100 vent connection. The installers did not use an adapter on mine; they just pushed a section of vent pipe over the PF100 connection, locked it on with sheet metal screws, and put a poor bead of hi temp RTV around the outside of the joint. The inner wall of that vent pipe is on the inside of the PF100 connection and the outer wall of the vent pipe is on the outside of the PF100 connection. The installer used Simpson Duravent pellet vent pipe.

    [​IMG]
  14. Ejectr

    Ejectr Minister of Fire

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    Thank you for that photo and thank you and the others for all your help. I see what I have to do and will be doing it as soon as the temps go back up this week after our marvelous pre Halloween snow storm is done. Many thanks.
  15. dmaclaren

    dmaclaren Member

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    You need to be careful with your install as it is not to SPEC.

    With that, you may be in violation of your local code and the insurance company, if anything happens, could refuse to cover you. I would take the time to use an appliance adapter.
  16. exoilburner

    exoilburner Feeling the Heat

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    Thanks for the warning, but what spec are you referring to? The local Harman dealer service department installed it about 3.5 years ago. They used Harman install instruction specs for the vent pipe. I would think the Harman instructions would take precedence. From the initial estimate to the final invoice they never mentioned an adapter for the vent pipe.
  17. Ejectr

    Ejectr Minister of Fire

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    Well after the 14" snow storm that knocked out my power for 7 days, I had a chance to pull the adapter off the exhaust pipe. I found the gap that is between the pipe and the furnace enclosure as had been discussed. There was one part of the circumference where the gap was quite large. I sealed the gap with high temp RTV, let it set and then put the adapter back on and sealed the outside of the adapter. Results....Smoke smell from the hot air ducts completely gone. Thank all of you for your diligent help. I notified my venting installer to make a note to seal that when he does PF100's from now on. Sure would have saved me a lot of work.

    Now....I do have smoke coming from somewhere on start up in the basement. I stood in the dark with a flash light and when I smelled it, I went searching, but couldn't pin point it. It seems to be strongest and from what I saw the short time it was firing up, it's coming from the convection fan area. That thing just sits metal to metal with 3 thumb screws clamping it down. I notice one of the thumb screws hits the seat at an angle instead of straight on. Could possibly be bent. I'm going to try and straighten it out tomorrow.

    If it is leaking at the convection fan base, how can you seal that having to get in there to clean? Any comments appreciated.
  18. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    The leak is likely actually in the exhaust system.

    Check your combustion blower and make certain it isn't leaking there. Also where the blower housing attaches to the stove,
  19. Ejectr

    Ejectr Minister of Fire

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    I meant to say combustion blower in my post and it came out convection blower.

    Suppose the combustion blower sealing surface is leaking. How can you seal that when it is metal to metal held on with 3 thumb type butterfly screws and that whole unit needs to be removed regularly for maintenance of the fan?
  20. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    If that blower isn't seated evenly then there isn't likely a full seal. Take care of your screws.

    I'm surprised that they haven't put a gasket there.

    There are also decent flexible easy to remove sealants.

    All combustion blowers need to be removed regularly, however they need to be sealed while operating.
  21. exoilburner

    exoilburner Feeling the Heat

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    After cleaning the combustion blower I have found if I am not carefull it is very easy to clamp the combustion blower slightly cocked in its mounting surface. The shoulder of the sealing overlap is very thin making it difficult to feel if it is seated flush in the hole. You can not see in there so only way I have found to feel if it is seated correctly is after inserting it in it's hole I press it in and twist it CW and CCW until it twists smoothly. You may need to clean the mating surfaces too.

    [​IMG]

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