Ministry of the
Solicitor General

Wood Stove Dos and Don’ts

Wood Stove Dos and Don’ts

By Yosh Imahori, P. Eng.,
Fire Protection Engineer, OFMEM

In Ontario, wood stoves are a popular and economical heating source. Traditionally, these stoves have been fuelled using firewood, but emerging alternative fuels such as wood chips, pellets and biomass are presenting other options to homeowners. Before use, it’s important for homeowners to know what products their woodstoves have been certified to use.

Use of wood pellets

In recent years, the use of wood pellets, as a fuel, has become more common due to the ease of storage and lower cost. As a result, a variety of rack and basket insert products to burn wood pellets in sealed wood stoves have been introduced into the market. Owners should be aware that the use of these products may result in the voiding of the stove’s certification, product warranty and/or insurance claims where the wood stove causes a fire. An insurance claim may be rejected as the certification of the stove may be invalidated since there may be no testing that demonstrates that the stove is compatible with these insert products and/or that it meets the requirements of the original design standard.

Applicable standards

The Ontario Fire Code requires that solid fuel burning appliances be installed in accordance with the CAN/CSA B-365 standard, “Installation Code for Solid-Fuel Burning Appliances and Equipment”. This standard makes reference to the ULC S627 standard, “Space Heaters for Use with Solid Fuels”. The ULC S627 standard requires that the appliance installation, maintenance and operation requirements list the recommended type of fuel to be used. Although wood pellets are generally considered an acceptable fuel for indoor heating, the wood stove that is used to burn wood pellets must specify this specific fuel type as appropriate.

Many wood stove manuals and pellet stove manuals follow the requirements of the ULC S627 standard with respect to installation and operating instructions and they also specify what type of fuel should be used. Although homeowners can buy combination log and pellet stoves, most retail wood stoves do not recommend both types of fuel. It is clearly stated in user manuals that the misuse of the stove, including improper fuel, would void the warranty for these stoves.


On the surface, these products may assist in the use of an alternative wood fuel, but if your wood stove was not certified with an insert already in place, or it has not received subsequent certification, the insert should be avoided. If homeowners are hoping to use alternative fuels, there are many multi-fuel products that are certified for home use.