I have an opportunity to purchase a used wood stove that I intend to use to heat my garage  / workshop. Are there any possible problems I should be aware of before I make the purchase?

There are a few issues you may want to consider and be aware of before you purchase a used wood heater. First, there is the issue of insurance. If you require or want insurance on the building where this appliance is installed the insurance company usually wants an inspection report from a municipal, regional district or WETT certified technician. 

 If the wood heater is not certified by a testing agency like ULC or Warnock Hersey or if it is UL rated (american standard) then you may have trouble getting an inspector or a WETT technician to certify that the appliance is sound and that you have installed it correctly. This is due in part to the usual absence of specifications for clearances to combustibles that were listed in the original manual that was long ago lost or discarded.

There is also reluctance on the part of inspectors and technicians to say everything is okay when hidden damage may exist. There are, none the less, generally accepted generic clearances to combustibles for uncertified wood heaters contained in a wood burning appliance manual which is usually available without charge at most municipal and regional district building departments. However, some inspectors and WETT technicians will still refuse to inspect these uncertified heaters. This manual, by the way, is full of useful tips about all aspects of installing and using wood heaters and fireplace inserts. I recommend it as a “must read” for all new and experienced wood burning folks.

If the heater is certified (check for a label on the side or back of the heater) then it will usually specify the minimum required clearances to combustibles (drywall is considered combustible because of the paper facing) as well as hearth protection requirements. Try to get the original owner’s manual from the seller. Check inside the heater firebox for cracks and warped or fatigued metal. If there are cracked or missing firebrick don’t be alarmed. Firebricks are readily available at most building and hardware stores and they can be easily removed and replaced.  Then install the heater to the manufacturer's specifications.  Connect the heater to a certified metal wood burning chimney or a conventional ceramic lined chimney flue (read last week’s column for details) and have the manual, with the clearances you used, ready when the WETT technician or inspector comes for review of the installation. Happy wood burning. ‘Tis the season!