Hot Water Cylinder Sizing: Where to Find a Reliable Calculator for UK Homes?

Getting hot water cylinder sizing right is one of the most consequential decisions in any heating system installation. An undersized cylinder creates persistent hot water shortages during morning peak demand; an oversized one wastes energy heating a volume of water that is never fully used. A reliable sizing guide takes into account the property type, […]

Comparing Leading Unvented Hot Water Cylinder Manufacturers for Domestic Use

The UK domestic market for unvented hot water cylinders is served by a number of established manufacturers, each with strengths in particular areas. When comparing options, the key differentiators are material, insulation quality, warranty provision, installation efficiency, and the breadth of product range for different heat sources. The criteria that separate leading manufacturers Why OSO […]

Best Hot Water Cylinders for Commercial Buildings

Selecting the right hot water cylinder for a commercial building demands a different set of criteria to domestic specification. Capacity, recovery speed, energy efficiency, build quality, heat source compatibility, and the availability of long-term service and warranty support all carry significantly greater weight when specifying for a commercial building. What to look for in a […]

How do you calculate hot water cylinder size?

Calculating the right hot water cylinder size is one of the most important decisions in any hot water system installation. An undersized cylinder leads to frequent cold water during peak demand; an oversized one wastes energy heating water that is never used. The correct approach balances property size, number of occupants, peak demand periods, and […]

Who can install an unvented cylinder?

In the United Kingdom, unvented hot water cylinders must by law be installed by a qualified engineer who holds a current Unvented Hot Water (G3) qualification. This is a legal requirement under Part G of the Building regulations (Approved Document G). Why a G3 qualification is required:Unvented cylinders operate at mains pressure and store water […]

What size unvented hot water cylinder do I need?

Choosing the right size unvented hot water cylinder is essential for reliable hot water supply and energy efficiency. Unvented cylinders operate at mains pressure and store a set volume of hot water that must meet peak demand between recovery periods. Here’s our guide to selecting the right domestic hot water cylinder. Start with the property, […]

Top-rated indirect hot water cylinder brands for UK homes: Key considerations

The UK market for indirect hot water cylinders is led by a handful of specialist manufacturers, each with distinct strengths in material quality, energy efficiency, warranty provision, and installer support. What to look for in a top-rated indirect cylinder: OSO Hotwater consistently ranks among the top-rated indirect hot water cylinder manufacturers in the UK. Manufacturing […]

Welcome to our new members of the Sales team

🎉 Welcome aboard! 🎉 We’re delighted to welcome Gary Muir and Richard Stubbs to the team as our newest members of the Sales team. Both bring a wealth of experience, energy, and enthusiasm, and we’re really looking forward to the expertise and fresh perspective they’ll add as they get started. At OSO, collaboration and support […]

LG acquires the OSO Group

LG Electronics Inc., a global leader in home appliances and consumer electronics with sales of USD 64 billion and headquartered in Seoul, Korea, announced today that it will acquire all shares in OSO Group AS – the European market leader in stainless steel, smart and energy-efficient hot water tanks. Focusing on heating OSO Group will […]

Energy transition at ISH 2025 – Join OSO Hotwater!

OSO Hotwater is taking a lead in the the energy transition with innovative products, and is present at ISH 2025!OSO Hotwater will present innovative solutions that help decarbonize buildings and energy systems designed for various markets across the worldEngage with experts to find optimum solutions for your need.  We look forward to meet you at […]

Ethical guidelines

Over 85 years OSO Hotwater has earned the trust from suppliers, co-workers and customers. We are still going to earn, and manage, this trust in an exceptionally good way, and value the opinion of our partners.

Our guiding targets:

  1. Safe products, manufactured by safe processes
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  3. Correct products delivered on-time
  4. Cost- and energy efficient processes

OSO Hotwater AS

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