What is a gas califont?

A gas califont is the name used by plumbing professionals for a tankless hot water heating system. These are sometimes also called instantaneous gas hot water, instantaneous hot water or continuous flow hot water.

Essentially, a gas califont hot water system is one that heats your water as you use it, instead of having water stored and heated in a hot water cylinder.

How does a califont work?

The short explanation of how a gas califont works is that a heating unit, powered by gas, heats cold water as you use it – providing you with limitless hot water.

The more detailed and technical explanation of how a gas califont works is this:

The unit consists of a cold water supply pipe; a hot water pipe exiting the unit; a gas supply pipe; a fan; a burner; the heat exchanger; an electronic control unit (ECU); the flow sensor and the hot water valve. The flow sensor inside the unit detects when an outlet is opened and requires hot water.

The sensor is connected to the ECU, which controls the fan and burner. It turns on the burner and fan, heating the incoming cold water as it flows through the heat exchanger. A thermostat works to regulate the amount of gas combusting in the burner, maintaining the water temperature to a set amount.

This function is controlled by a sensor detecting the water temperature on the exit side of the heat exchanger. This allows for continuous hot water that ever runs out.



Is it possible to install a gas califont?

The average homeowner cannot install their own gas califont. Even if you’re a keen DIYer, in NZ you must be a qualified gasfitter authorised to work on gas appliances in order to install a gas califont.

Requirements for installation

As well as providing endless hot water, a gas califont also offers the benefit of not needing a lot of space for a water cylinder. A gas califont is installed outside of the home, so it doesn’t require much room for installation.

All that is needed for the installation of a gas califont is a source of gas, either LPG bottles or mains gas.

Different types of gas califonts

There are many califont manufacturers in New Zealand, but two really stand out from the rest – Rheem and Rinnai.

Both brands offer a range of califonts with a flow rate of approximately 16L-27L per minute, suiting a wide variety of households. At Sumich Plumbing & Drainage, we are experts in installing both brands and trust them both for their quality and service.

What size gas califont do I need for my home?

Depending on what brand you choose, gas califonts can provide a flow rate anywhere from 5 litres per minute to about 30L per minute.

The size depends on a few factors, such as the number of people in the household (and whether any of these are teenagers), the number of bathrooms, the number of baths/showers taken each day, and whether there are baths/showers taken at the same time on most days.

For a household of just two people, a flow rate of 10-20L/min would be fine. A household of four or more people would need a higher flow rate, of approximately 25-27L/min.

Gas califont installation regulation NZ

The installation of gas califonts (and all other gas appliances) is strictly regulated in NZ.

NZ industry guidelines state that all gas connections require a qualified and licensed gas fitter to undertake the work to get the appliance connected, installed and working; this applies to natural gas and LPG. Each installation also requires a certificate of compliance to be completed when the work is finished.

Sumich Plumbing & Drainage are certified gas fitters, which means our work is heavily regulated to make sure the work we do is safe and managed responsibly. We provide a gasfitting and repair service for natural gas and LPG, and all jobs are fully guaranteed.

Our gas fitters can help you with gas hot water cylinders, instantaneous gas water systems, gas heaters, gas fireplaces, gas hobs and ovens, bottled gas systems, and gas heating systems.

Will my gas califont work in a power outage?

While a gas califont relies on gas to heat the water, they do also need electricity to power the hardware for the heating process. If there is a power outage, a gas califont will not work.

This is probably the only disadvantage we can think of when it comes to using a gas califont to heat your household water. Gas califonts, or instantaneous gas hot water systems, have a range of other benefits that make them an economical and efficient way to heat your water.

If you have any questions about a gas califont and all of its benefits, feel free to get in touch with the friendly and experienced team at Sumich Plumbing & Drainage.