Unvented Cylinder Replacement

What unvented cylinder replacement covers

A like-for-like replacement or upgrade, completed with the safety checks and commissioning an unvented system requires.

• Site survey to confirm cylinder type, location, access and pipework condition
• Sizing advice based on property demand, recovery rate and available space
• Isolation, drain down and safe removal of the existing cylinder
• Installation of the new unvented cylinder and any required valves and controls
• Checks of key safety components (temperature and pressure relief, expansion control)
• Review of discharge pipework route and termination for compliance
• Filling, pressure testing, commissioning and performance checks
• Handover guidance and relevant certification or notification where required

When this service is the right fit

You may need a replacement if your cylinder is corroded, leaking, losing pressure, tripping the immersion, or producing inconsistent hot water. It is also worth considering when parts are becoming uneconomical to repair, or when an extension, bathroom upgrade, or higher occupancy means your current cylinder is undersized. Landlords and small commercial sites often choose replacement to reduce downtime and improve reliability.

How the replacement is delivered

First, the system is assessed to confirm the correct cylinder specification and any constraints around access, electrics, and existing controls. The old unit is isolated and drained, then the new cylinder is fitted with the required valves and correctly connected to hot, cold and heating feeds. The system is then commissioned, safety devices are tested, and hot water performance is checked before sign-off.

After installation: what you get and what to do next

You will be shown how to operate the controls and what normal running looks like. If any pipework, valves, or discharge arrangements need future attention, this is highlighted clearly so you can plan ahead. For best reliability and safety, unvented cylinders should be serviced periodically to keep safety controls working as designed.