Tankless water heaters, or instantaneous or on-demand water heaters, provide hot water without using a storage tank. Unlike traditional tank-style systems that heat and store water, tankless heaters use advanced sensors to detect water flow and heat it directly as it passes through the system.

This results in a continuous hot water supply without waiting for the tank to refill and reheat. With tankless water heaters, you only heat the water you need when you need it.


There are a few key factors to consider when switching to a tankless water heater. Carefully examine your current system’s age and functionality and your household’s hot water usage patterns. Also, assess your available power supply, space constraints, and budget.

Tankless heaters may require electrical upgrades to handle the high heating demands. Weigh installation costs against potential energy savings from not constantly heating a large volume of stored water. Consult with a professional to determine if a tankless water heater is the right fit for your home.

What Types of Tankless Hot Water Heaters Are There?

Two main types of tankless hot water systems exist electric tankless hot water systems and gas tankless water systems.

The electric system is straightforward – it operates by circulating water over several heating elements like in a kettle. These instant heat water heater units generally use between 20 and 60kw of power per hour. By comparison, your standard electric hot water service generally uses around 3.6kw of energy per hour. Still, they must heat over multiple hours and keep the stored water hot for future use.

The gas system can use either natural gas or LPG, and like the electric systems, it uses a lot of gas at once to get the heat into the pipework as required, rather than storing it like a storage system.

Pros and Cons of Tankless Electric Systems

Tankless electric water heaters offer certain advantages but also have some significant drawbacks.

Lower Upfront Cost
– Electric tankless heaters have a lower equipment purchase price compared to traditional tank-style water heaters.

Compact Size and Flexible Installation
– Electric tankless units are lightweight and compact with no bulky storage tank.
– Their small size allows convenient installation in tight spaces like under cabinets or ceilings.

Simple Maintenance
– Electric tankless heaters have relatively simple internal components and no moving parts.
– This translates into more straightforward maintenance requirements down the road.


Cons of Electric Tankless Water Heaters

High Electricity Demands
– Electric tankless heaters have high power demands, ranging from 15kW to 27kW.
– Most homes require electrical upgrades to handle these heavy loads.

Increased Operating Costs
– The high electricity usage leads to higher utility bills than conventional water heaters.

Incompatible with Solar/Off-Peak
– The constant high power draw makes electric tankless units incompatible with solar, batteries, and off-peak tariffs.

Key Considerations
– Carefully weigh electrical system capacity, operating costs, and compatibility with renewable energy.
– Consult experts to determine if electric tankless is the right fit.

Critical Factors in the Tankless Decision

When installing a tankless or conventional storage water heater, carefully evaluate your current setup and household needs. Storage tank water heaters have been the norm for decades, but tankless models are gaining popularity for their space savings, efficiency, and performance.

Look at the age and functionality of your existing unit. Old, inefficient models may be ready for replacement. Check your available power supply and infrastructure. Tankless heaters have high demands, often requiring upgrades. Consider natural gas availability, too, as gas tankless heaters are energy efficient.


Weigh the budget for the purchase and professional installation costs. Storage heaters are generally less expensive upfront. Calculate long-term operating costs, as tankless can save on energy bills.

Factor in your hot water usage patterns. Do you need high flow rates for multiple showers or appliances? Tankless heaters deliver endless hot water on demand.

Also, think about environmental impact. Tankless heaters only heat water as needed, avoiding standby energy waste from keeping a tank hot 24/7. This improves energy efficiency.

Consider space constraints, as tankless options are very compact. And check for rebates on energy-efficient models. Consult with experts to determine if tankless technology is right for your home.

Recommendations Based on Situation

For an older, inefficient electric storage tank system, we recommend upgrading to a new energy-efficient tankless gas water heater. The gas models provide an endless hot water supply while slashing energy costs.

If you have an electric off-peak storage tank and are satisfied with its performance, you may wish to replace it with a new equivalent system. The off-peak power savings make these units economical.

An electric tankless unit may be your best option with limited space and budget. The compact electric heaters can fit almost anywhere and have lower upfront costs. Just be mindful of the higher operating expenses.


Homes with access to cheap natural gas are ideal for gas-fired tankless water heaters. The gas systems will maximize efficiency and savings.

For solar power users, we advise avoiding electric tankless units. Their high energy demands at all hours often don’t align well with solar energy generation. Traditional solar storage tanks are a better pairing.

Consult water heating specialists to assess your situation and determine which system suits your household’s needs and constraints.

Making the Right Choice for Hot Water

Tankless water heaters present pros and cons compared to traditional storage tanks. The optimal system depends on your household’s specific needs and conditions. For help determining the best water heating solution for your home, contact The Brisbane Plumbers at 0450 932 850 or visit our page for any queries or questions. Our expert team is always available to assess your situation and explain the options to make the right choice.