Hot Water Cylinder Installation
A hot water cylinder stores pre-heated water for instant delivery to all outlets. Whether you need a replacement vented cylinder, an upgrade to a pressurised unvented cylinder, or a new cylinder as part of a system boiler installation, our G3-qualified engineers handle the complete installation.
What's Included
- Cylinder supply (vented or unvented, correct size for household)
- Full installation including all pipe connections
- Expansion vessel (unvented cylinders)
- Pressure reducing valve and temperature/pressure relief valve (unvented)
- Immersion heater installation or transfer
- Cylinder thermostat wiring
- Commissioning and legionella temperature test
- G3 Unvented System Certificate (for unvented cylinders)
At a Glance
Frequently Asked Questions
What size hot water cylinder do I need?
A family of 4 typically needs 210 litres. For 2 people, 120–150 litres is usually sufficient. We calculate the right size based on your household size and peak demand.
What is the difference between vented and unvented cylinders?
A vented (gravity-fed) cylinder is open to atmosphere via a header tank in the loft — suitable for older systems. An unvented (pressurised) cylinder connects directly to the mains supply, giving you powerful mains-pressure hot water at every outlet.
Do I need a special qualification to install an unvented cylinder?
Yes — unvented cylinders must be installed by a G3-qualified engineer. Our team is fully G3 qualified. Do not allow an unqualified engineer to install an unvented cylinder — it carries legal and safety risks.
Book Hot Water Cylinder Installation in Corby
Fixed price, Gas Safe engineers, next-day availability.