back puffing

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

iceisasolid

New Member
Jan 3, 2011
110
North Central Idaho
Last night I noticed some back puffing for the first time (only been a little more than week). It was windy as could be. I awoke to cold coals after loading up the firebox and then when appropriate closing it down for a steady run overnight. Last night, however, I was not able to keep the stove cooler than 550 after closing it up. It stayed that way for hours and was that way when I went to bed.

This morning, I had a tough time relighting the stove. I primed the flue with a newpaper torch, but couldn't get much done. It took me too long to light a fire and keep it going. The same thing occured this evening, I needed to restart the fire. There was back puffing and difficulty starting the fire. I recalled that I should consider opening the basement window- and then viola, the smoke stopped coming in when the loading door opened.

I began inspecting the flue and could hear a draw coming from the universal flue adapter and the adjustable double wall pipe. I placed a match to it and the flame was promptly sucked into the connection.

So here are my questions:

Would you seal the stove/pipe/chimney connections- flue to flue adapter, flue adapter to adjustable pipe, adjustable pipe to chimney or just open the window when there is a low pressure system outside.

If I did seal the pipe, should I expect better long burn control or should I just expect the satisfaction of making it airtight and be happy if there is any other bonus to be had with this fix.

Do I need to use stove cemement for the connections or is there a his temp silicone that works well for this application.

Thanks for reading.
-Ray
 
Seal it with stove cement, not silicone. It will help. Also, if there is a cleanout door on the chimney, seal it. Are there any competing appliances in this space like a furnace, boiler, hw heater, dryer, bath fan? Try turning them off to see if they are affecting stove draft.
 
There are dryers, bathroom vents, electric hot water heater, and a furnace. None of them are on at the moment. This AM, evening opening the window doesn't seem to be helping the back puffing today. The top stove plate was showing 300 F and there was fire in the box too. The smoke set off the alarm today. We are having a low pressure system at the moment with some snow last night. There is no place for an OAK on the stove either. Hmm. All last week we had mild temps but high pressure.

The back puffing is occuring only when opening the door for reloading. The stove has been running for only 12 days now. I am only burning wood and newspaper for starting, of which I have needed to start it 3 times. Is it possible that Ash could build up and effect it?

Maybe I should take off the impingment plate tonight and look at the combustor?
 
Is it still windy? I know with my stove when its real windy that i have a heck of time getting a fire going, then when i do it burns like a mother even with it choked down. Plus other little things like puffing. I just always chaulk it up to the wind.
 
Was the flue cleaned before the stove was started? Has the cap been checked?

Also, is this a cat stove? If so, is the cat bypass being opened before the stove door opened and when the stove is being started?

It would help to know a bit more about the installation, particularly the entire flue connection and chimney. Can you describe it in detail?
 
Is the stove installed in your basement?
 
Sounds like it might be time to run a brush through the chimney.
 
BeGreen said:
Was the flue cleaned before the stove was started? Has the cap been checked?

Also, is this a cat stove? If so, is the cat bypass being opened before the stove door opened and when the stove is being started?

It would help to know a bit more about the installation, particularly the entire flue connection and chimney. Can you describe it in detail?

This was a brand new installation with out of the box pieces. I have at least 2 ft of pipe above the apex of the roof. I looked at the cap yesterday, it was brown and discolored but not clogged. The cat bypass damper is always opened to allow for venting when starting a fire and when adding wood. I follow England's instructions on how to start a fire and load wood.

The stove flue collar was resealed with fiberglass gasket 3/8 inch as per England Stove Works, the universal flue adapter was fitted and placed and fits tight- no leaks there. The Adjustable MetalBest DSP is placed in the Flue adapter per manufacturer specs- but it leaks air a little. The DSP runs into the chimney which sits on a support box in the Basement ceiling (upstairs family room floor). The chimney runs through the 2nd level of the home in a closet with a chase built. There are fire stops at each pass through in the home. The attic portion of the chimney has an insulation barrier, then a 15 degree offset, then the roof kit and 4 more feet of pipe out the roof with the roof kit (flashing/storm collar/round top chimney cap). Until the wind picked up, there was no problem (for 9 days-when I first fired it up).

I have now taken off the impingment plate and looked at the cat- there was only a very fine discoloration of fly ash on the bottom of the combustor. I used the vaccum on it and there was minimal change in appearance. None of the honeycomb cells appears clogged. There is a clear opening to the flue. The flue has a minimal amount of light browning on the sides. I can't see up the top because my mirror doesn't have the angle to see up and possibly because it is night time.

Hmm, my daughter asked me if we could run the furnace tonight instead of the stove...
 
Gator eye said:
Sounds like it might be time to run a brush through the chimney.

I looked at the cap on the roof (previously I looked from theground only) and saw that there was about 1/4 inch of creosote on the top of the cap and maybe 1/8 inch on the pipe. I ran my brush down the pipe (I only have 16 feet of flex rod) and I returned about 1/4 - 1/2 cup of creosote. I cleaned it up and reassembled the impingment plate.

The firebrick does not run all the way the door of the stove. It was full of ash almost to the bottom lip of the door. I cleaned that out too. I decided to try a fire without sealing the flue/DSP connection. I opened the window and quickly noticed that the draft was present again- it is not windy tonight, however. I started the kindling and noticed that the smoke rolled into the place at the lower portion of the stove door lip and swirled in a channel then went up and out the damper bypass opening. The smoke was rolling down and off the top lip of the front of the stove, but not coming out. Pretty neat to watch when it is not billowing into the stove room.

Thus far no smoke. I hope this this issue is resolved, at least for tonight.

I don't think that my daughter will be getting the furnace this evening. We will be using good old fashioned wood heat tonight. I think that I will keep that area in the bottom front of the stove cleaned out much better. Perhaps it is a channel of some sort? My next day off I will seal the DSP/flue connection.

Question, how much wiggle room should the chimney pipe have on it when I run the brush through it? Should it be rock solid or should it be a little a little flexible say to the tune of 1/8-1/4 inch of motion?

I am not so certain that an 1/8 inch of creosote would affect the draft like that or the cap with the 1/4 in would also, but then again, I am new to wood burning and I am ready for your comments. Thank you for taking an interest.

-Ray
 
Good to hear things are working better. You had remarked on damp wood in an earlier post, thus my suspicions on the flue and cap. Damp fir will burn well due to the high oil content, but it has the potential to gunk things up too. Get your next season's wood stash split and stacked soon and you will avoid a lot of grief next winter.
 
Status
Not open for further replies.