Instantaneous Hot Water Heater

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Licensed hot water plumbers across Brisbane, Perth & Adelaide

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4.6 · 2,000+ Google reviews

Instantaneous, or continuous flow, hot water gives you an endless supply without a bulky storage tank. When yours shows an error code, stops heating, or needs replacing, our licensed plumbers and gas fitters can repair or install it fast.

We size, install, repair and replace continuous flow systems across Brisbane, Perth and Adelaide, with upfront fixed pricing and same-day service where we can.

Why choose Same Day Trades for continuous flow hot water?

We are local, licensed and insured plumbers who do this work every day, so we get it right the first time, with no mess and no surprises on the invoice.

Fully licensed and insured plumbers
Upfront fixed pricing before we start
Same-day service where we can, with 24/7 phones
Workmanship guaranteed and the job left clean
Servicing Brisbane, Perth and Adelaide

Whatever the job, you get honest advice and a tidy, professional result.

What is an instantaneous hot water system?

An instantaneous hot water system, also called continuous flow or tankless, heats water on demand as it passes through the unit, rather than storing it in a tank. When you turn on a hot tap, cold water flows through the unit, is heated instantly by a powerful gas burner or electric element, and comes out hot, for as long as you need it. Because there is no tank, you never run out of hot water, and there is no standby heat loss from a tank sitting hot all day. The compact unit mounts on a wall, saving space. It is an efficient, increasingly popular choice for homes of most sizes.

How continuous flow hot water works

The clever part of a continuous flow system is that it only heats water when you actually use it. A flow sensor detects when a hot tap is opened and fires up the burner or element to heat the water as it passes through a heat exchanger, delivering a steady stream at your set temperature. When you turn the tap off, the heating stops. This on-demand operation is why there is no standby heat loss and no tank to run dry. Gas continuous flow units are the most common and efficient, though electric instantaneous units exist for smaller applications. We help you choose and size the right unit for your home.

The benefits of instantaneous hot water

Continuous flow systems offer several clear advantages:

Endless hot water, you never run out, even with back-to-back showers
No standby heat loss, as water is heated only when used, saving energy
Space-saving, the compact unit mounts on a wall, with no bulky tank
Precise temperature control, often with a wall controller
Long lifespan, continuous flow units often last longer than storage tanks
Efficient, especially gas models for homes with a gas connection

For many households, the combination of endless hot water and energy efficiency makes continuous flow the ideal choice.

Gas vs electric instantaneous systems

Instantaneous systems come in gas and electric versions, and gas is by far the most common for whole-home hot water. Gas continuous flow can deliver a high flow rate to supply a whole house, is cheaper to run where you have a gas connection, and is the standard choice. Electric instantaneous units are generally suited to single outlets or smaller applications, because heating water instantly with electricity draws a lot of power, making a whole-home electric instantaneous system demanding on the electrical supply. For most homes wanting endless hot water, a gas continuous flow unit is the practical choice, and we will advise what suits your connection and demand.

Sizing by flow rate

Unlike storage tanks measured in litres, continuous flow systems are sized by flow rate, measured in litres per minute, which reflects how much hot water the unit can deliver at once. The right size depends on how many hot water outlets you are likely to run simultaneously, one shower needs less flow than two showers plus the kitchen tap running together. A unit that is too small will struggle to keep up when multiple outlets run at once. We calculate your likely peak simultaneous demand and recommend a unit with the right flow rate, so you have endless hot water even at the busiest times, without paying for more capacity than you need.

Common instantaneous hot water problems

We repair all common continuous flow faults, including:

No hot water, often an ignition fault, gas supply issue or a tripped unit
Error codes displayed on the unit or controller
Fluctuating water temperature
Water not hot enough, or taking too long
The unit cutting out during use
Leaks from the unit or connections

Continuous flow units have electronic controls that display error codes to help diagnosis. We read the codes, diagnose the real cause, and carry out the repair, or advise replacement if the unit is old or beyond economical repair.

Understanding error codes

One advantage of modern continuous flow units is that they have electronic controls that display error codes when something goes wrong, which helps pinpoint the fault. An error code might indicate an ignition failure, a gas supply problem, a flow or temperature sensor issue, overheating, or a fault with the fan or flue. While the code narrows down the problem, interpreting it and carrying out the repair safely, especially on a gas unit, is a job for a licensed professional. We know the common codes across the major brands, diagnose exactly what the unit is reporting, and fix the underlying cause, so your endless hot water is restored reliably.

Water temperature fluctuations

A common complaint with continuous flow systems is water temperature that fluctuates, sometimes called the cold water sandwich, where the water runs warm, then cold, then hot again. This can happen when taps are turned on and off in quick succession, or it can indicate a problem with the flow sensor, the unit sizing, or the plumbing. Some fluctuation at very low flow rates is normal, as the unit needs a minimum flow to fire. But persistent or significant temperature swings point to a fault or a sizing issue. We diagnose the cause, whether it is the unit, the sizing or the plumbing, and resolve it so your hot water stays steady.

Repair or replace?

Continuous flow units generally last longer than storage tanks, often 15 to 20 years with servicing, so repair is frequently worthwhile. If your unit is not too old and the fault is a repairable component, an igniter, sensor, valve or fan, a repair is usually the best value. Once a unit is old, repeatedly faulting, or beyond economical repair, replacement makes more sense, and newer units are more efficient. We give you an honest assessment and a price for both repair and replacement, so you can decide. Because continuous flow units are long-lived, repairing a unit that is not too old is often the sensible, economical choice.

Switching to continuous flow

Replacing an old storage system is the ideal time to switch to continuous flow and enjoy endless hot water with no standby losses. If you have a gas connection, switching to gas continuous flow is straightforward and often reduces running costs compared with electric storage. The compact wall-mounted unit also frees up the space your old tank took. Switching may involve some gas and plumbing work to suit the new unit, which we will explain and quote upfront. For most households tired of running out of hot water or paying to keep a tank hot, moving to continuous flow is a worthwhile upgrade, and we handle the whole changeover.

How much does an instantaneous system cost?

The cost depends on the unit size (flow rate), the brand, and the installation complexity, including any gas and plumbing work to suit the new unit. As a general guide, installed gas continuous flow systems usually run around $1,200 to $3,500, with larger, higher-flow units at the upper end. Repairs are far cheaper than replacement, with a sensor, igniter or valve fix being an affordable job. Switching from storage adds any changeover work. Rather than guess, we give you an upfront fixed price before any work starts, whether it is a repair, a like-for-like replacement, or a switch to continuous flow.

Servicing your continuous flow unit

Continuous flow units benefit from periodic servicing to keep them running efficiently and to extend their already long life. Servicing checks the burner, heat exchanger, ignition, sensors, filters and gas pressure, cleans components, and catches small issues before they cause a breakdown. Regular servicing also helps maintain efficiency, so the unit keeps delivering hot water at the lowest running cost, and it can be a requirement to keep the manufacturer warranty valid. We service continuous flow units of all major brands, keeping your endless hot water reliable year after year. If your unit has never been serviced, it is worth booking one to keep it in top condition.

Same-day hot water service

No hot water is miserable, so we treat continuous flow faults and replacements as a priority. Our phones are answered around the clock, and we can usually get a licensed plumber and gas fitter to you the same day across Brisbane, Perth and Adelaide. We can read the error codes, diagnose the fault, and carry out many repairs on the spot, and where a replacement is needed we can often supply and install the same day. We will give you an upfront price for the repair or replacement, and get your endless hot water flowing again fast.

Licensed, guaranteed plumbers

Instantaneous hot water work involves water, and for gas units, gas connections, so it is licensed work that is never a DIY job. Our licensed plumbers and gas fitters install, repair, service and replace continuous flow systems to Australian Standards, fit the required safety and tempering valves, and provide compliance certification. You get honest advice on repair versus replacement and the right unit size, upfront fixed pricing, same-day service where we can, and workmanship we stand behind. For a plumber near you for instantaneous hot water, we cover Brisbane, Perth and Adelaide.

Instantaneous hot water FAQs

Do instantaneous systems ever run out of hot water?

No. They heat water on demand, so you get a continuous supply as long as water and gas or power are flowing.

Are continuous flow systems cheaper to run?

Yes, generally. They have no standby heat loss from a stored tank, and gas continuous flow is especially economical.

What size continuous flow unit do I need?

It is sized by flow rate (litres per minute) based on how many outlets you run at once. Our plumber will recommend the right size.

Why is my continuous flow system showing an error code?

Error codes flag faults like ignition, water flow or sensor issues. We use the code to diagnose and repair the unit quickly.

Can you repair my instantaneous hot water system?

Often, yes. Ignition, valve and sensor faults are repairable. If the unit is old or uneconomical to fix, replacement is better value.

How much does a continuous flow system cost?

As a guide, gas continuous flow runs around $1,500 to $3,000 installed. We provide an upfront fixed quote.

Can I switch from a storage tank to continuous flow?

Yes, though it may need extra gas, water or electrical work. We will assess your setup and quote the changeover.

Do you offer same-day service?

Yes. We carry common parts and units and can often repair or replace the same day across Brisbane, Perth and Adelaide.

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bill dear

Coda was fantastic did a great job

GFd Gail Gorton

Great speedy service, very friendly Job well done Highly recommend Jack for repair man

Ian Liddell

Diego and Kosta, greatly appreciate the great work you both did. Impeccable service and workmanship.

Davo Zillas

Jordan was super helpful with investigating our leaking issue

julee johnson

Jack was fabulous great guy 👍

Grace Vinci

I had my Safety switch/ circuit breakers replaced by Jesse. He was helpful, polite and thorough, explained and shown me what needed to be done. He was informative also explained all options available to me giving me a choice, which I appreciated. Before leaving Jesse also made sure everything was in working order before leaving the premises.