We want to provide the maximum savings with the minimal effort, which is why the Viva Extreme boiler can be filled with a high quantity of logs with a maximum  length of 52 cm. Combined with its high efficiency, this

will keep your home warm the whole day and will not

only save you money but also the most precious thing of all – the time.



Who should buy a Viva GT heating boiler?

The Viva Extreme boiler is intended for people who favour a more traditional type of heating with logs but still want to follow all the modern trends and make use of the latest technologies. This boiler is especially recommended for people who want to minimize their heating costs and those that produce their own firewood.


Only 15 minutes of your time per day.

Many people consider log burning a very time-consuming and troublesome undertaking that requires you to constantly deliver new logs and keep the fire burning.


Our goal was to design a boiler that combines log burning with a level of comfort that only Waltis can provide. With this in mind we designed a boiler that incorporates the latest trends and standards from Austria and was certified by the TGM institute in Vienna.



In 2017, for the boiler VIVA GT we obtained the certificate of accredited laboratory KIWA Cerment Italia. The measurements were carried out under strict supervision and control. Despite the harsh conditions the boiler has achieved excellent results. In addition to high efficiency (90.8%), extremely low emissions of harmful gases and dust particles were measured. Maximum permissible limit for emitted harmful dust particles according to the standard EN 303-5: 2012 is 40 mg / Nm3. Viva GT takes care of our health and the environment with only 12.3 mg / Nm3 (13% O2).


In the Viva GT boiler the gas is gasified in the combustion of wood gas.


The sophisticated principle of the combustion of wood logs, produced 25/35 kW thermal energy, which is in the form of the heated hot water stored in the reservoir (1500 to 2000 l).


The amount of heat stored in the storage room allows the heating of the residential building up to 24 hours. 


The major advantage of the system compared to the conventional heating firewood with longer intervals loading logs in the cleaning of the boiler and the lower fuel consumption.



cesta k tamu 61, Maribor, Slovenia