OSO Hotwater is the world’s largest manufacturer of stainless steel unvented hot water cylinders.
Manufactured in Norway since 1932, OSO cylinders have won countless awards for quality and sustainable production.
Unvented hot water cylinders connect directly to the water main and provide high pressure hot water to showers and taps throughout the building
Register your cylinder for warranty and book for service and or repair with OSO’s Approved Service and Warranty team.
Joining OSO Approved Certified Installer gives you access to approved spares, training, and work revenue opportunities.
OSO Partner offers better rewards, more support, promotions, training and exclusive events.
At OSO Spares you can buy all current and historic official OSO cylinders and spare parts.
Quality
Throughout 60 years we have perfected the stainless steel heater. The combination of material choice, robotized production and intelligent solutions gives the OSO products unbeatable lifetime.
Energy efficiency
OSO heaters have the lowest heat loss on the market, and are designed to give maximum performance. This gives our products the lowest power consumption and a unique lifespan economy for our customers.
Environment
50 years of efforts and investments to unite people, environment and industry, and for this given several awards. In three generations our objective has been the same:
Protect Our Beautiful Planet!
News
Energy transition at ISH 2025 – Join OSO Hotwater!
THE FUTURE ROLE OF HOT WATER CYLINDERS IN BALANCING GRID DEMAND
Innovation timeline
1941
Production of potato collector cogs and planting equipment during the war
1945
Production of copper-lined storage tanks 200 – 50,000 litres resumes
1955
Provision storage tanks tripled the capacity while only taken half the space
1932
Norway’s first autogenous welded storage tank is produced at Oslo Svesiebedrift
1935
Welded cooking pots and wood boilers complements the range of products
1938
Development of wood-burning boilers which provides both heat and hot-water