Slight smoke on start up

[Carriet]

I just installed a Pelpro pp70 and noticed a slight smoke smell upon start up. Did the flashlight trick and going there is a little bit of smoke that comes out from the t connector. But it's not at the seam( I have foil tape over that), it comes from the bottom of it.
It only happens on start ups and the smell/smoke goes away when the pellets ignite. Have a CO detector in the room that does constant monitoring of levels and nothing registers. Still worries me though.
Any ideas on how to fix this? Thanks in advance!!

 

[bogieb]

Wrap silicone tape around the angles at the T. I havn't found a T or elbow that didn't leak (I'm sure they are out there, just I haven't found them). I wrap all the angles as a matter of routine. With silicone tape there is easy removal if needed and I'm not that good at using the foil tape - there are always creases, which is a pathway for smoke.

OTOH - if the stove and/or pipes are new, it could be regular burn off. However, that is usually a distinctive smell and not a smoky odor.

 

[Carriet]

Thanks. The only problem is that it's not coming from the angles, it's coming from the bottom of the cap, where the vent openings are. I was too worried so I went out and bought another one. I also took ALL the exhaust pipes apart and made sure they were completely cleaned out. Sealed everything back up with the silicone inside and foil tape on the outside and tried it out today. There's STILL some smoke coming from the bottom of the cap It only seems to be at start up but I won't run it with the thermostat now because of that. What am I doing wrong????

 

[clux]

Sounds like a draft issue to me. How long is the pipe run and is the exit possibly pointing into the wind?
It has vent openings in the cleanout T? Mine doesn't.

 

[Carriet]

Sounds like a draft issue to me. How long is the pipe run and is the exit possibly pointing into the wind?

I have it vented up through the house and out the wall. It goes up about 6 feet and out to the side of the house. There is a good breeze that goes through that area. I do not have a vent cap on the outside, it just sticks straight out. Should that be something I purchase?

 

[johneh]

I have had my stove for over 20 years
The cap on the clean-out Tee has always leaked a little smoke on start-up.
Silicon tape has worked well to seal it and is easy to remove when cleaning pipe.
My co and smoke detectors have never registered the smoke or co and
yes they have been tested and work

 

[Carriet]

I have had my stove for over 20 years
The cap on the clean-out Tee has always leaked a little smoke on start-up.
Silicon tape has worked well to seal it and is easy to remove when cleaning pipe.
My co and smoke detectors have never registered the smoke or co and
yes they have been tested and work

I do have the cap sealed at the seam. Is it okay to seal the bottom of the cap as well? I thought it was vented on the bottom for the draft. Sorry if I sound dense, I'm still learning. 🙂

 

[clux]

I do have the cap sealed at the seam. Is it okay to seal the bottom of the cap as well? I thought it was vented on the bottom for the draft. Sorry if I sound dense, I'm still learning. 🙂

Pellet stove install requirements vary by your code I suppose so YMMV, but there's not vent in my cleanout cap, and I've never had smoke on startup.

 

[bogieb]

Can we get a picture of that cap? I am having trouble envisioning what you are decribing as I have never heard of a vented cap.

 

[tbear853]

I do have the cap sealed at the seam. Is it okay to seal the bottom of the cap as well? I thought it was vented on the bottom for the draft. Sorry if I sound dense, I'm still learning. 🙂

NO ... the cap on the tee is for cleaning, it should seal to the inner wall of the pel vent tee. What you maybe see thinking is a vent ... is the air space between the inner and outer portions of the pel vent. The inner liner of pel vent is stainless steel, it should be the only portion contacting pellet flue gasses.

That cap is not vented nor would you want it vented, especially not so in the house. Even outside, convection currents or draft is a help mate for the stove's blower, venting a cap at the tee would destroy a large bit of the draft. You want that draft pulling stove combustion remnantys, not free air.

That air gap helps to support the inner thinner more expensive stainless steel liner, provides and air space to reduce condensation inside the vent, it goes a long ways to preventing contact burns too, and it provides connection methods where there's usually a seal in there to seal the inner sections together.

When I put my stove in in '92, I decided then .... NO TEE in the house. I have the third one I've ever had outside the house at the end of that single straight pipe from the stove ... then from the tee the flue goes up. To clean, I leave the tee, just remove the cleanout cap and that up piece. I will use a strong vacuum end of a big leafe blower or shop vac through the tee back towards the stove though. I can see where the tee has leaked smoke ... just like the first two did. I wrap and strap an extra piece of galvanised steel cut from old pel vent between it and my wall, but when I remove it I see the black stains in it. The pellet stove vents are operating under pressure as the exhaust is pushed by the stove. In operation, there is positive pressure in the vent, not a vacuum like a wood stove or fire place, etc. where convection currents move the exhaust once a draw is established after a fire started. Even oil stoves and gas stoves, coal, etc ... use convection currents.