The Science of Efficiency: Mains Pressure Hot Water Cylinders Explained

mains pressure hot water cylinder,

When installing or upgrading your home’s hot water system, mains pressure systems are often an appealing option. Compared to traditional gravity systems, their high pressure and flow rates make them advantageous. However, there is an essential rule of thumb to remember when considering a mains pressure hot water system:A mains pressure system’s effectiveness depends heavily on the mains water supply’s specifications.

Specifically, your mains supply lines’ water pressure and flow rate will affect your new hot water system’s performance. An undersized or low-pressure mains supply could mean your shiny new system fails to reach its advertised potential.

Before switching to a mains pressure hot water cylinder, it’s wise to understand how these systems function. Doing your homework beforehand allows you to set accurate expectations and make the most informed choice on a new hot water system for your unique home setup.

How Mains Pressure Systems Work

Mains pressure hot water systems provide endless hot water at the same pressure as the cold water taps. But how does it work exactly?

The cold water taps are straightforward – they connect directly to the incoming mains cold water line. However, delivering hot water on demand from the mains requires additional equipment explicitly designed to heat the water while maintaining full pressure.

The main components are:

  • Cold water supply – Consistently delivers water pressure via the primary utility lines. Experts advise that 300 kPa should be the minimum pressure.
  • Storage cylinder – An insulated tank that holds hot water ready for use. It includes electrical heating elements to heat the water.
  • Tempering valve – Delivers tempered water to faucets and showerheads by combining hot water from the cylinder with incoming cold water.
  • Circulation pump (optional) – Ensures instantaneous hot water delivery by recirculating hot water from the cylinder back into the plumbing loops.

The cylinder holds hot water at all times. When you turn on a hot water tap, cold water is forced into the bottom of the cylinder by the mains pressure, which also forces hot water through the piping to reach the open tap. This maintains a steady supply of hot water.

The Efficiency Advantage

1. Energy Efficiency

Mains pressure hot water cylinders shine when it comes to energy efficiency. Unlike older continuous flow systems, they only heat the water you need. This avoids wasting energy on excess hot water, cutting costs on your energy bills and reducing your carbon impact.

2. Rapid Hot Water Delivery

The pressurized design also enables rapid hot water delivery when needed. Open any tap and enjoy an immediate gush of hot water with a strong, consistent flow. This responsiveness is especially beneficial on busy mornings when the whole household simultaneously demands hot water.

3. Suitable for Multiple Taps

Finally, mains pressure cylinders reliably supply multiple taps at once without sacrificing water pressure. Whether you have a small or large family, everyone can access hot water simultaneously without experiencing frustrating drops in flow. This convenience makes daily routines hassle-free for the whole household.


Mains pressure hot water cylinders are crucial in providing homes with an efficient hot water supply. Its key benefit is its energy efficiency. At Hot Water Cylinders NZ, you can get a wide selection of mains pressure cylinders, including electric, gas, and solar-powered models. Switching to a mains pressure cylinder lets you experience firsthand how clever engineering optimizes hot water efficiency.



Leave a Reply

Your email address will not be published. Required fields are marked *