Kroll has released a wood [BIOMASS] gasification hydronic heater, or boiler. Our KK wood boilers are clean and reduce smoke, ash and soot. Hydronic heating systems help reduce dryness in closed environments and are highly sustainable. Forget burning expensive LPG or natural gas fuels for hydronic warmth and get a controlled heating solution with Kroll’s KK series. The KK Series is completely reliable and safe for use.