The paper discusses Enhanced Combustion Woodstove (ECW) technology, developed by EPA in response to the field observation that woodstoves certified by EPA as being clean burning were not achieving the level of emission control 'seen' in laboratory tests. ECW technology is based on the fact that woodstove emissions are caused by the incomplete combustion and pyrolysis of wood in the primary combustion zone. To achieve low emissions, the stove must incorporate a secondary combustion zone above the wood which will hold flame at all times. Current noncatalytic woodstoves can achieve satisfactory secondary combustion only under fairly ideal conditions. Stable secondary combustion may not be achieved at typical low-fire conditions, leading to high emissions. Initial work focused on using an electrical glowplug (ECW electric) to ignite and add energy to the secondary combustion zone. Later work has focused on using a gaseous fuel (ECW gaseous or ECWG) for this purpose.