Unvented Cylinders
An unvented hot water cylinder offers a genuinely different experience of hot water in the home. Fed directly from the mains supply rather than from a cold water tank in the loft, an unvented cylinder delivers hot water at mains pressure meaning powerful showers, faster-filling baths and consistent performance at every outlet in the house. Thermwise offers unvented cylinder fitting and replacement as a standalone service, carried out by qualified engineers who hold the necessary G3 unvented cylinder competency.
Whether you’re upgrading from a traditional vented system, replacing an ageing cylinder or fitting a new unvented system as part of a broader heating project, our team can manage the job from start to finish.
How Unvented Cylinders Work
Unlike a vented hot water system, which relies on gravity and a cold water storage tank to feed the cylinder, an unvented cylinder connects directly to the mains water supply. This means the water pressure at your taps and showers is determined by the incoming mains pressure rather than the height of a tank, which typically results in a much stronger flow throughout the property.
Unvented cylinders are sealed systems that operate under pressure, which is why they must be fitted and serviced by a qualified engineer holding G3 certification. This is a legal requirement, and it’s essential for the system to operate safely. Thermwise engineers are fully qualified to work on unvented systems, giving you complete confidence that the installation meets all current regulations and safety requirements.
What to Expect from the Fitting Process
Before any work begins, our engineer will assess your existing hot water setup, incoming mains pressure and the available space for the cylinder. We’ll recommend a cylinder size and model suited to your household’s hot water usage and confirm a clear, itemised quote before proceeding.
On the day of the fitting, we carry out all necessary pipework connections, fit the required safety components including the expansion vessel, pressure relief valve and tundish, commission the system and test it thoroughly before handover. We’ll walk you through how the system works, how to check the pressure and what to do if you notice anything unusual — so you’re fully informed from the outset.
Find Out More About Unvented Cylinders
If you’re considering an unvented cylinder for your home or need an existing system replaced, Thermwise is ready to help. Contact Thermwise today to discuss your requirements and receive a clear, honest quote from our qualified engineers.
