New chimney leaking, tight house, Jotul F370

[PutneyVT]

We just installed a Jotul F370 in our new "super insulated" home and have run into a problem. The metalbestos style chimney is leaking slightly between the segments...We had an expert come out and take a look at the situation. He believes that a wood stove can't be installed in house like ours without a dedicated air source...The stove creates a slight negative pressure in the house which is what is causing the chimney sections to leak.

Has anyone run into something like this - any advice?

Thanks.

 

[Heatsource]

does cracking a door or window near the stove stop the problem?
if not, then outside air likely wont help.

please describe your installation, brand of pipe, total height, number of offsets if any, etc.

 

[webby3650]

That sounds like a clogged cap or other obstruction. It's common for the stove to smoke out or for it to be sluggish, but leaking pipe joints is typically a clog.

 

[Oldman47]

Your local expert may be right. Try cracking a window as Heatsource recommended. If the problem goes away, you are a candidate for an outside air kit, OAK. Most manufacturers have a standard way to connect an OAK to your stove and are happy to sell you the kit. Truly air tight homes can suffer from this issue.

 

[PutneyVT]

Please excuse the delay in responding, I really appreciate all the help.


The stove is a Jotel F370, which unfortunately neither our local dealer nor Jotel North America seem to know much about. The chimney is either double walled Duravent or Metalbestos and about 30 feet long. The house is modern and ultra-insulated. High-tech fans keep a slight negative indoor pressure.


There seems to be a very small leakage of smoke between segments of the double wall chimney pipe as it passes through the second floor. We shut off the nearest fan and that seems to have helped the problem. But of course we'd like to turn it back on as the house was designed with it running…


Everything is new and when we looked up the chimney, everything looked clear.


Opening a door near the stove does not seem to have any effect on the stove itself, so it doesn't seem to be air starved. Some local experts feel that the stove is adding to the negative pressure in the house and we should supply it with air.


Is there any way to seal the connections between these double walled pipes? Or should we put in the air-supply to the stove (not cheap).

 

[webby3650]

If your house was designed with kind of system, how on earth did the stove get overlooked? It must have its own air supply! Under these conditions it doesn't have a chance to work properly.

 

[PutneyVT]

Just to clarify, the stove appears to be working fine. The problem is a small amount of leakage between the section of double wall pipe passing through the second floor.

 

[webby3650]

Just to clarify, the stove appears to be working fine. The problem is a small amount of leakage between the section of double wall pipe passing through the second floor.

If it's leaking smoke, the stove isn't working fine. It's a symptom of a big issue. It should be sucking air in, rather than leaking.

 

[begreen]

I would expect the air exchange system to keep a slight positive pressure in the house, or at least balanced and neutral, but not negative. Negative pressure is not good with a wood stove and can cause other appliances to back draft as well as the potential to pull unwanted air or radon into the house.