Icing in chimney

[AKBurner]

My father in law has a BK Princess . He’s burning spruce and birch in a 25 foot chimney, running the stove dampened way down to get 12 hour burn times. Last year he went to start a fire and and smoke filled the house. He called a chimney guy and he said there was ice that closed off the chimney about 2/3 of the way up. I told my father in law that he needs to be burning hotter fires and not constantly burning with the stove chocked down. He refuses and says his chimney is too tall. I run an old Vigilant without a catalytic so I’m not as familiar with that setup. Can you constantly run those stoves so low?

 

[stoveliker]

If the cat is still alive, then yes, you can run low.
But it is imperative to keep the flue above 212 F to avoid water condensation as that can result in creosote accumulation.

I presume the chimney is outside. Class A or lined brick?

If lined brick, it should be an insulated liner. That helps keeping temps up.

 

[AKBurner]

If the cat is still alive, then yes, you can run low.
But it is imperative to keep the flue above 212 F to avoid water condensation as that can result in creosote accumulation.

I presume the chimney is outside. Class A or lined brick?

If lined brick, it should be an insulated liner. That helps keeping temps up.

Yes cat still works, it’s a new stove. Chimney is inside high vaulted room. The top 7’ is outside. Class A chimney.

 

[stoveliker]

I don't understand how at 16 ft of a 18 ft inside run+7 ft outside one can get ice...
Unless it formed higher up and slid down?

But yes, the stove can run this low, but the flue needs to keep a certain minimum temp to not clog up with ice or creosote.

The stove is so efficient that most of the heat is shed inside the home before it goes up the flue.

Does he have a flue probe thermometer? If so what does it read?

How tall is the stove pipe before it transitions into class A? And is it single wall or double wall stove pipe?

 

[AKBurner]

I don’t know exact numbers for the ice, just going off what the chimney guy said. it has to be freezing above the roofline somewhere. That makes sense about the efficiency part. It’s double wall, no temp gauge on the pipe. I’ll pick one up and see

 

[stoveliker]

Get a probe thermometer and drill a hole to stick it in.
Condar has good ones online.

Magnetic surface ones don't work on double wall pipe.

 

[EbS-P]

It had to cool off to get inspected. I wonder if it was a bit clogged with creosote then it kept drafting and condensing room air/water on the pipe then it froze up??

It’s odd but sounds plausible.

 

[Dieselhead]

It’s normal for icicles to form off the cap but not in or around the flue. A pic of this would be very helpful.