Unvented Hot Water Cylinders: Benefits, Costs, and Installation
An unvented hot water cylinder gives you mains-pressure hot water throughout your home. It costs more to install than a vented system but delivers much better performance.
What is an unvented cylinder?
An unvented hot water cylinder is a pressurised system connected directly to the mains water supply. Unlike a traditional vented cylinder that relies on a cold water tank in the loft, an unvented system has no tank - the mains pressure drives the hot water to your taps and showers. See also our overview of pressurised water systems.
What are the benefits?
Mains-pressure hot water everywhere in the house means:
- Powerful showers without needing a pump
- Consistent flow even with multiple taps running
- No cold water tank taking up space in the loft
- Cleaner water as it is not exposed to the atmosphere in an open tank
How much does it cost?
An unvented cylinder installation typically costs between £1,500 and £2,500 including the cylinder and labour. The exact price depends on the cylinder size, the brand, and the amount of pipework involved. It is more expensive than a vented system, but the performance difference is significant.
Who can install one?
Only a G3-qualified engineer can install an unvented hot water cylinder. This is a legal requirement because of the higher pressures involved. All of our engineers who work on unvented systems hold the G3 qualification.
Does it need servicing?
Yes - unvented cylinders should be serviced annually. The engineer checks the expansion vessel, temperature and pressure relief valves, and the tundish (the safety overflow device). This keeps the system safe and maintains any manufacturer warranty.
Need help with this?
Call us on 01932 943 009 or email info@hphsolutions.co.uk. We cover Surrey, Hampshire, Berkshire and London. Free quotes, no obligation.
