Top 10 signs of an unsafe wood stove?

[John Ackerly]

Hi folks,
The Alliance for Green Heat has been trying to get the DOE to ensure that states require wood stoves to be inspected when they do energy audits, just like other combustion appliances and main house systems. If they were, auditors would be helping to educate homeowners, urging them to call a stove specialists and for low-income households, they could get repairs or even a stove replacement for free. One of the biggest hurdles, we are told, is giving auditors a simple list of some things that they can visually inspect in 3-4 minutes and check off a list. We have sketched out what we think are the top 10 things an auditor with a tape measure can easily check on a free-standing wood stove (not an insert or pellet stove). Do you think we got it right. What would you add, remove or say differently? Thanks for your help. John A.

Ten signs that a wood stove is a health and safety hazard

The following checklist list is a quick way to do an initial safety inspection for a free-standing wood stove. It does not apply to wood stove inserts or pellet stoves. If any of the following are evident, the stove is likely a health and safety hazard.

1. No ceiling/wall thimble.
2. Single wall pipe with less than 18-inch clearance to combustible.
3. double wall pipe with less than 6-inch clearance.
4. Floor protection doesn’t extend at least 8 inches on side and back and 18 inches in front.
6. Stove clearances to combustibles fail to confirm to requirements on metal safety label on back of stove.
7. Stoves clearances are less than 36 inches to combustible if there is no metal label on back of stove.
8. A crack in the steel or cast-iron firebox.
9. Visible creosote dripping down stove pipe or wall where stove pipe exits.
10. Chimney or stove pipe has no cap on top.

 

[begreen]

I'd modify this list a bit:

1. No ceiling/wall thimble or a thimble with inadequate shielding or improper clearances
2. Single-wall stovepipe with less than 18-inch clearance to combustible or double-wall stovepipe with less than 6-inch clearance. (Note: some dw stovepipe requires 9" ceiling clearance)
3. Stovepipe passing through a wall or ceiling.
4a Floor protection doesn’t extend at least 8 inches on the sides and back and 18 inches in front. (16 in the US)
4b Floor protection that does not have the proper R-value for the stove.
5. Chimney pipe clearances that are not honored (usually 2" from any combustible)
6. Stove clearances to combustibles fail to conform to requirements on metal safety label on the back of the stove or stove manual.
7. Stoves clearances are less than 36 inches to combustibles if there is no metal label on the back of the stove.
8. A crack in the steel or cast-iron firebox. A stove that is modified by removing parts that affect clearances (shields, firebrick).
9. Visible creosote dripping down stove pipe or wall where stove pipe exits. Stovepipe that is installed upside-down.
10. Improper chimney installation, Inadequate chimney height, not honoring the 10-3-2 rule. No chimney brace at the 5' level. No cap. (Stovepipe should not be used as chimney pipe. If it has a cap, it is being used wrong.)

 

[stoveliker]

R-values will be hard to do in 3-4 minutes. Not easily measured. most homeowners don't even know what material it is.

-I would add something about well-closing doors (gaskets, e.g. dollar test, if enough time). If they are not closing well enough, it tends to be less controllable, and thus less safe.

-Positive slope of horizontal pipe runs?

-Too long of a horizontal pipe run? (Smoke in the house is not safe either.) Very case dependent though (with a 40' chimney, one can deal with a 4' horizontal run...)

-Cracks in the glass.

-(Clear) Evidence of burning trash/anything not cordwood (or coal, or pellets).

-Visual custom modifications to a stove with a UL label on the back (if no label, the non-listed rules applied already).

 

[EatenByLimestone]

Terra cotta inspection to see if a masonry chimney is sound.