Pressure & performance
Mains Pressure Hot Water Upgrades
Low-pressure hot water is common in older New Zealand homes. It works, but it often means weaker showers, noticeable pressure changes when another tap is used, and hot and cold flow that never quite balances. A mains-pressure upgrade changes how water is delivered through the home.
At a glance
Mains Pressure Upgrade — key points
- Stronger, more balanced shower performance
- Better handling of simultaneous hot-water use
- Removal of ceiling header tanks in many cases
- Pipework and valve assessment required
- Suits households upgrading an old cylinder
- Professional assessment before any work
How low-pressure systems work
Traditional low-pressure (open-vented) systems rely on a header tank in the roof space to supply the cylinder. The available pressure comes from the height of that tank, which is why hot-water flow is typically weaker than cold.
These systems were standard in New Zealand for decades and many are still in service today. They are usually identifiable by the ceiling tank, the vent pipe and the different flow rate between hot and cold taps.
Why households consider mains pressure
Mains pressure delivers hot water at the same pressure as your cold supply, which usually means better shower performance and more consistent temperature when multiple outlets are used.
It also opens up compatibility with modern tapware, showers and appliances that are designed around equal pressure.
- Weak or disappointing shower flow
- Hot water pressure dropping when another tap opens
- Renovating a bathroom or kitchen
- Replacing an end-of-life low-pressure cylinder
- Installing modern tapware or shower systems
What an upgrade usually involves
An upgrade is more than swapping the cylinder. Existing pipework must be able to handle mains pressure, and pressure-limiting, expansion-control and tempering components must be correctly specified.
In some homes, pipework in walls and floors may need attention, which affects both cost and scope. This is why an on-site assessment by a qualified professional is essential — we do not provide DIY plumbing instructions.
Questions
Frequently asked questions
Can any home be upgraded to mains pressure?
Most can, but not all upgrades are straightforward. Existing pipework condition, incoming supply pressure, space and layout all influence whether an upgrade is practical. A qualified plumber will assess your property.
Will I still need my header tank?
In many mains-pressure conversions the ceiling header tank is no longer required for hot water. Your installer will confirm what applies to your specific system.
Ready to upgrade your hot water?
Tell us what you need and we'll connect you with a suitable independent hot-water professional in your area.
No obligation. Free to request. Your details may be shared with a suitable independent provider so they can respond.