The WETT Inspection
If you have a wood-burning appliance in Ontario, the acronym you will meet is WETT, usually because an insurer has asked for a report.
Short answer
WETT stands for Wood Energy Technology Transfer, a Canadian training and certification program for people who inspect and install wood-burning systems. A WETT inspection is an assessment of a wood appliance and its venting against the applicable codes and standards, and insurers routinely require one before binding or renewing coverage.
What it is and is not
A certification of the inspector, not of the appliance. WETT certifies people; the report then states whether the installation complies.
An assessment against the applicable installation code and the manufacturer instructions, which covers clearances, the venting, the hearth and the structure.
Not a guarantee and not a warranty, and not a substitute for a sweep.
Not the same thing as a home inspection, and most home inspectors are not WETT certified.
Not a government licence — it is an industry certification program, which is why the insurer asks for it by name.
And frequently a condition of insurance rather than a legal requirement, which is the practical reason most people get one.
Why insurers ask
Wood-burning appliances are a documented fire risk and a non-compliant installation is a much larger one. An insurer in Ontario will frequently require a WETT report before binding a policy on a house with a wood stove or an insert, and may require one at renewal or after a change. Having a current one makes the insurance conversation straightforward.
The levels
A visual inspection covers what can be seen without dismantling or special access — the appliance, the accessible venting, the clearances and the hearth.
A more detailed level adds accessible concealed areas and may involve removing panels or using a camera in the flue.
The most comprehensive level involves opening up concealed construction, and is used where a specific problem is suspected or after an incident.
For an insurance requirement, the visual level is usually what is asked for.
After a chimney fire, after a significant change, or where something is wrong, a higher level is appropriate.
And the report should state which level was done and what was not accessible, which is the honest part.
What gets checked
Clearances from the appliance and the venting to combustible materials, which is the most common failure.
The hearth pad: material, size and extension in front of and beside the appliance.
The venting: type, condition, joints, support, clearances, and the termination height above the roof.
The chimney: liner, condition, crown, cap, and the structure.
The appliance itself: certification label, condition, door seals, baffles and firebrick.
And the combustion air provision, which in a tighter modern Ontario house matters more than it used to.
Common questions
What does WETT certify?
The inspector, through a Canadian training program. The report then states whether the installation complies.
Why does my insurer want one?
Wood appliances are a documented fire risk and a non-compliant install is a much larger one.
Is a home inspection the same thing?
No. Most home inspectors are not WETT certified.