The new Free Flow 2014 (FF14 + FF15) series combines proven quality with state-of-the-art environmental technology.

Designed as a fully fledged wood-fired stove – and often used and proven as the only heat source –, one of the main qualities of the Free Flow hot air stove has always been the fact that rooms are heated fast and evenly. Due to the built-in ChimCat® catalyser of the combustion chamber and the currently three-stage combustion air supply, the FF14 burns as clean and as efficient as never before. The efficiency was considerably increased and is now 80%, which means a lower wood consumption for the same heating performance.


To meet the requirements of the 1st BImSchV (1. Bundesemissionsschutzverordnung, federal immission control regulation) and other European and/or national regulations governing the emission of wood log heating plants, a catalyser is built into all Bullerjan hot air stoves. The catalyser unit replaces the normally used fuel gas deflection plate. Due to the structure of the catalyser unit, emissions of carbon monoxide, hydrocarbons and fine particles are reduced by up to 90%.

The Chimcat catalytic converter decreases the environmentally harmful emissions of carbon monoxide and hydrocarbons reliably and lastingly. Fine particles are efficiently filtered from the exhaust gases and burnt up without residues due to the very high temperature in the catalyser unit.


The development of this catalyser by Dr. Pley Environmental GmbH was promoted by Deutsche Bundesstiftung Umwelt (DBU) and the low emission values and high efficiencies were verified and approved by the accredited German testing institute DBI-Gti in Freiberg.


The catalyser unit consists of three layers of catalytic converter cassettes (for FF14 type 02 of six layers) which are arranged over each other and are flowed through by the exhaust gas. The catalytic converter cassettes themselves include a ceramic pellet material which is catalytically coated with precious metals.

The catalytic coating reduces the activation energy of the oxidation of carbon monoxide and hydrocarbons into carbon dioxide and water. This means that these reactions take place faster than at a comparable temperature without catalyser, thereby reducing the environmentally harmful emissions of carbon monoxide and hydrocarbons lastingly and reliably.

The pellet material in the catalytic converter cassettes is simultaneously used as a fine dust / soot filter. Soot and dust are retained through the filter effect of the cassettes and is reburned to be residue-free by the very high termperature in the catalytic converter module. Any soot residue which can occur at the end of a burn-off is really burned-off when next igniting the stove.

The catalytic converter itself is low-service when used properly. However, at least once per heating season, possible residues (soot) should be removed on a regular basis. For cleaning purposes, remove the front cover plate and pull out the catalyser unit. The cartridges can be easily removed from the unit. Clean possible residues with a brush or an ash vacuum cleaner.