Low pressure HWC upgrade is one of the most common hot water jobs GoFox plumbers carry out across New Zealand. Many older homes still have low pressure systems, and converting to mains pressure makes a noticeable difference to daily life. However, it is not simply a case of swapping the cylinder.
This post covers what a low pressure HWC upgrade involves, what needs checking beforehand, and when to call a plumber.
Is a Low Pressure HWC Upgrade Worth It?
Low pressure hot water systems typically operate at between 10 and 50kPa. Mains pressure systems deliver up to around 500kPa, which is roughly six times stronger. Most new New Zealand homes are built with mains pressure as standard. A large number of homes over 20 years old, however, still run on low pressure.
The most common signs are weak shower pressure and difficulty running more than one hot outlet at a time. If your hot water flow drops when another tap runs elsewhere in the house, low pressure is likely the reason.
What Does a Low Pressure HWC Upgrade Involve?
A low pressure HWC upgrade is not a straightforward cylinder swap. Because the system operates at significantly higher pressure after the conversion, several components need checking before and during the job.
Your plumber will typically assess the following.
Pipework Older pipes may not suit mains pressure. Your plumber will check the condition and configuration of existing pipework and advise on what needs changing.
Tapware and shower fittings Taps and shower fittings designed for low pressure may not suit mains pressure. Your plumber can confirm whether tapware needs upgrading at the same time.
Tempering valve NZ plumbing regulations require a tempering valve to control water temperature at the tap. If your current system lacks one, the upgrade must include it.
Cylinder size and space Mains pressure cylinders are generally larger than low pressure units. Space in the hot water cupboard may need consideration, particularly in older homes.
Safe tray The NZ plumbing code also requires a safe tray with a drain connection for any indoor cylinder installation.
When Is the Right Time to Upgrade?
Because the job covers multiple components, costs run higher than a like-for-like cylinder replacement. However, the result is stronger flow throughout the home, better shower performance, and the ability to run multiple outlets at once.
Many homeowners time a low pressure HWC upgrade to coincide with their existing cylinder reaching the end of its life. Tackling both at the same time makes practical and financial sense.
Your local GoFox plumber can assess your existing setup, check pipework and tapware, and provide a clear quote before work begins. Visit our hot water cylinders service page to find out what we cover.
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Frequently Asked Questions
Can I upgrade my low pressure hot water cylinder to mains pressure? Yes. A low pressure HWC upgrade is a common job for a licensed plumber. It involves replacing the cylinder and assessing pipework, tapware, and compliance requirements. Your local GoFox plumber can assess your home and provide a quote.
Will my existing pipes handle mains pressure? Most homes can convert without major pipework changes, but your plumber needs to check first. Older or poorly configured pipes may need attention before the upgrade proceeds.
Do I need a new tempering valve? If your current system does not have one, yes. NZ plumbing regulations require a tempering valve on all hot water systems to limit tap water temperature.
Will my existing taps and shower fittings still work? Tapware designed for low pressure may not perform as well or last as long under mains pressure. Your plumber can advise whether upgrading tapware at the same time makes sense.
When is a good time to do a low pressure HWC upgrade? Many homeowners combine the upgrade with a cylinder replacement when their existing unit reaches the end of its life. Doing both at the same time is generally the most cost-effective approach.
