What is Tankless Water Heater?

A tankless water heater, also known as an on-demand or continuous flow water heater, heats water directly without storing it in a tank. It only heats water when you turn on a hot water tap.

When you turn on a hot water tap, cold water travels through a pipe into the tankless water heater unit. A powerful heating element, either gas-fired or electric, quickly heats the water as it flows through. The hot water then continues through the pipes to your tap or appliance. This process provides hot water on demand, eliminating the need for a storage tank. Tankless units deliver a constant supply of hot water. They don’t run out like traditional tank systems.

Tankless water heaters provide a constant flow of hot water and are an innovative solution to domestic water heating needs. Beyond merely furnishing hot water, they represent an evolution in how homeowners manage energy consumption and space in their homes. Yet, they come with their own set of challenges that merit consideration.

• With a tankless water heater, residents experience an uninterrupted supply of hot water, reflecting one of the foremost advantages. This system eliminates the inconvenience of depleted hot water supplies, ensuring that hot showers or other needs are always met.
• Space constraints in homes are alleviated by the compact nature of tankless water heaters. Freeing up room typically occupied by traditional bulky water tanks, these sleek units can be installed inconspicuously in smaller areas or even outdoors, if necessary.
• A notable attribute of tankless water heaters is their longevity. On average, these systems outlast standard tank water heaters by several years, a result of reduced corrosion given the absence of stored water.

• The upfront expense associated with the installation of a tankless water heater often exceeds that of traditional tank water heaters. Given the complexity of installation, which frequently involves upgrading natural gas lines or electrical systems, costs can accumulate swiftly.
• Uneven performance may be noticed during simultaneous demands for hot water, as tankless systems struggle with high flow rates required by multiple applications, like running the shower and dishwasher concurrently.
• Homeowners may encounter complications when retrofitting an existing setup to accommodate a tankless water heater. These challenges include ensuring adequate ventilation and making modifications to existing plumbing, which may necessitate additional expenditure.

When considering a move to a tankless water heater, evaluating both the advantages and the potential pitfalls is essential for making an informed decision. Each household’s individual needs and circumstances will dictate whether the benefits outweigh the drawbacks.

Two primary variants dominate the tankless water heater market: electric and gas. Each type operates distinctly and caters to varying household needs and preferences. Deciding between an electric and a gas water heater may depend on existing infrastructure, long-term energy savings, and the initial investment.

Electric tankless water heaters, known for their compact size, offer the convenience of installation in smaller spaces. The lack of a need for venting makes them a popular choice for interior spaces where gas models may not be practical. An ample supply of electricity and proper circuitry are prerequisites for installation, as these models draw significant electric current during operation. Homeowners often find these units preferable in regions with lower electricity rates or where natural gas is not readily available.

Gas-powered tankless water heaters provide hot water by combusting either natural gas or propane. The key advantage lies in their ability to handle high demands for hot water, making them suited for larger households. Installation requires access to a gas line and adequate venting to ensure the safe expulsion of exhaust gases. A greater initial investment than electric models may be offset by the long-term energy cost savings, particularly in areas where gas is more economical than electricity.

Prospective buyers should consult a qualified technician to assess their home’s compatibility with either system and to determine the most effective and efficient option. Upgrading the home’s electrical system for an electric heater or the installation of proper venting for a gas heater can significantly affect the installation process and overall costs.

Installing a tankless water heater is a more complex process than installing a traditional tank heater. It often requires a professional hot water plumber. Key considerations include:

• Venting (Gas Models): Proper venting is crucial for safe operation.
• Gas Lines (Gas Models): Existing gas lines may need upgrading to handle the higher demands of a tankless heater.
• Electrical Requirements (Electric Models): Electric tankless heaters require a dedicated circuit with sufficient amperage.
• Water Supply Lines: Ensuring adequate water pressure and flow is important.

Installation costs vary depending on the type of heater, location, and complexity of the job. Generally, expect to pay between $1,000 and $3,000 for professional installation. The price of the unit itself adds to this cost. Tankless water heaters typically cost between $500 and $2,000.

Regular maintenance ensures optimal performance and extends the lifespan of your tankless water heater.

• Flush Your System Annually: Flushing removes mineral buildup that can reduce efficiency. Use a solution of white vinegar and water. This process involves connecting hoses and running the solution through the unit.
• Check the Water Filter: Some models have a water filter that requires periodic cleaning or replacement. Refer to your owner’s manual.

• No Hot Water: Check the power supply (electric) or gas supply (gas). Inspect the venting for blockages (gas). Ensure the water supply is turned on.
• Low Hot Water Pressure: Check for mineral buildup and flush the system if necessary. Low water pressure in your home can also affect flow rate. Contact a plumber.
• Error Codes: Modern tankless heaters often display error codes. Consult your owner’s manual to diagnose the problem. Contact a professional if needed.

Determining the appropriate capacity for a tankless water heater rests on two pivotal measures: liters per minute (LPM) and temperature rise. LPM refers to the volume of hot water the unit can deliver in a minute, while temperature rise is the increase from its original temperature to the desired output temperature. These indicators directly influence a unit’s ability to meet the hot water demands of a household.

LPM refers to the hot water flow rate that a tankless water heater can provide. It is the Australian equivalent of GPM (Gallons Per Minute), which is used in some other countries.

To determine the LPM you need, add up the flow rates of fixtures and appliances you expect to use simultaneously:

• Shower: 9.5 L/min
• Sink faucet: 3.8 L/min
• Dishwasher: 11.4 L/min
• Washing machine: 11.4 L/min

For example, if you want to run a shower and sink simultaneously, you’d need a tankless water heater that can handle at least 13.3 L/min.

As a general rule in Australia, you should choose a hot water system that can supply at least 20 litres per minute (L/min) of hot water per person.

Temperature Rise is the difference between the incoming cold water temperature and the desired hot water temperature.

1. Determine your incoming water temperature (varies by location and season in Australia)
2. Decide on your desired hot water temperature (typically 50-60°C for residential use)
3. Subtract the incoming temperature from the desired temperature

For example, if your incoming water is 10°C and you want 50°C hot water, your required temperature rise is 40°C.

When choosing a tankless water heater in Australia:

1. Calculate your maximum required LPM
2. Determine your needed temperature rise
3. Choose a unit that can meet both requirements simultaneously

For instance, if you need 13.3 L/min with a 40°C temperature rise, look for a unit that can provide at least that flow rate at that temperature rise.

• Climate variations: Australia’s diverse climate means incoming water temperatures can vary significantly across the country and seasons. This affects the required temperature rise.
• Energy efficiency: Look for models with high energy rating labels, indicating better energy efficiency.
• Gas vs Electric: Gas-fired tankless water heaters are more suitable for larger households with higher hot water needs, while electric models are ideal for smaller Australian households with lower hot water demands.
• Installation requirements: Ensure your home can accommodate the chosen system, especially if switching from a traditional tank system to tankless.
• Government incentives: Some Australian states offer incentives for installing energy-efficient appliances, including tankless water heaters. Homeowners may be eligible for Small-scale Technology Certificates (STCs) under the Renewable Energy Target scheme.