Megaflo Eco cylinderWhen specifying an unvented cylinder, it’s important to opt for a well-made, high-quality, efficient, high-performance product.

On face value all unvented cylinders might look the same, but closer inspection will reveal important differences. The key things to consider are materials, performance, energy efficiency, product approvals and warranties.



As unvented cylinders store water under pressure, it is essential that they are strong, durable and corrosion resistant. Duplex stainless steel is by far the preferred material in the manufacture of unvented cylinders, as it has outstanding and unique corrosion resistant properties. It is also lightweight, giving it a strength-to-weight ratio advantage.

For longer cylinder life we use a combination of laser and TIG welding, and butt joints to avoid crevices, and carry out comprehensive, state-of-the-art post weld treatments.

On our direct cylinders we use titanium immersion heaters, and on our indirect cylinders we use Superloy 825.


Performance and efficiency

Market leading brands will invest in the performance and efficiency of their products, whether that’s by improving flow rates, recovery times, the amount of stored hot water available or standing heat losses.

We insulate Megaflo Eco’s T&P valve to reduce heat loss, and use an L shaped heating element rather than a straight one to ensure the whole cylinder is heated, and a patented inlet diffuser that ensures excellent stratification and hot water output.


Product approvals

Hot water cylinders should be constructed and tested to established British and European standards, as well as being manufactured in a factory which has accredited Quality Management Systems. Third party approvals – such as from WRAS and KIWA – demonstrate good quality and performance.



Products with extended or comprehensive warranties will offer peace of mind.

It’s important to check the terms of any warranty offered, and any limitations hidden in the T&Cs. Particular things to be aware of are whether onsite parts and labour costs are included, and what the level of support offered is like.

All unvented cylinders might initially seem the same, but there are important differences between brands. High-quality products offer the best possible performance, efficiency and innovation and good value for money in the long run.

Megaflo Eco is the UK’s marketing leading unvented cylinder, with over one million Megaflo cylinders installed across the country. For further information, visit or call 01603 420 220.

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