Introduction to Hot Water Systems
Having a reliable hot water system is essential for every Australian home. Hot water systems heat cold water and deliver it throughout your home so you can enjoy hot showers, do laundry, wash dishes, and more. There are several types of hot water systems to choose from, each with their own pros and cons.
Most Australian homes have either an electric or gas storage hot water system.
Storage systems consist of an insulated tank that holds a set amount of heated water. Cold water enters the bottom of the tank where it’s heated by gas burners or electric heating elements. Storage systems consist of an insulated tank that holds a set amount of heated water.
Storage systems provide a consistent supply of hot water. Storage systems provide a consistent supply of hot water. Gas systems have lower running costs but require more maintenance.
However, you may run out if multiple showers are taken in quick succession.
Tankless or instantaneous water heaters are great space savers as they heat water on demand without a storage tank. However, their flow rate may be limited during simultaneous use. Solar hot water relies on the sun’s energy but needs a backup conventional system for cloudy days.
When choosing a hot water system, consider factors like your household size, usage patterns, and budget. Work with a licenced plumber to select the right system and ensure proper installation and maintenance.
Types of Hot Water Systems
There are several main types of hot water systems used in Australian homes:
Electric Storage Systems
Electric storage, or tank systems, consist of an insulated tank that holds a set amount of heated water. Electric heating elements at the base heat the water. As hot water is used, more cold water enters the bottom of the tank to be heated.
Gas Storage Systems
Gas storage systems also utilise a tank, but use gas burners to heat the water instead of electric elements. Gas systems typically have lower running costs than electric.
Tankless/Instantaneous Systems
Tankless water heaters provide hot water on demand without a storage tank. They heat water as it flows through a heat exchanger. Flow rate may be limited during simultaneous use.
Heat Pump Systems
Heat pump systems use electricity to move heat from the air into the water. They are energy efficient but work best in warmer climates.
Solar Hot Water Systems
Solar hot water systems use solar thermal collectors to heat water. Solar energy is used whenever possible, with a gas or electric booster as backup on cloudy days or at night.
Storage Tank Water Heaters
Storage tank water heaters are one of the most common types of hot water systems found in Australian homes. As the name suggests, they consist of an insulated storage tank that holds a reservoir of heated water.
Inside the tank, electric heating elements or gas burners heat the water. Cold water enters the bottom of the tank, gets heated, then rises to the top as hot water ready for use. The tank continually replenishes its supply of hot water.
Electric storage tank water heaters contain electric heating elements, usually near the bottom of the tank. They use electricity to heat the water. Gas storage tank heaters have gas burners that heat the water instead.
Storage tank water heaters provide a consistent supply of hot water. The tank acts as a buffer, so you get a steady stream of hot water even if multiple showers or taps are running at once. This makes them a popular choice for large households.
A downside is that storage tank heaters can take up more space than other types. Regular maintenance is also required to keep them operating efficiently.
Tankless/Instantaneous Water Heaters
Tankless or instantaneous water heaters provide hot water on demand without the need for a storage tank. Instead of heating and storing a tank of water, tankless systems use burners or heating elements to heat water as it flows through a heat exchanger.
Cold water enters the system and passes across the heat exchanger. The burners or elements instantly heat the water to the desired temperature before sending it to the hot water outlets. This on-demand design means you never run out of hot water.
Tankless heaters only heat water when needed, making them very energy efficient. However, flow rate may be limited if multiple hot water taps are opened at once, as the heater can only heat so much water at one time.
Professional installation is recommended to ensure proper sizing, venting and gas line requirements are met.
They also last longer than storage tank heaters. They also last longer than storage tank heaters. Tankless systems are compact since no tank is required.
Heat Pump Water Heaters
p>p>p>p>p>p>p>p>p>p>p>p>p>p>p>p>p>p>p>
Solar Water Heaters
Solar water heaters are an environmentally friendly option that relies on energy from the sun to heat water. They use solar thermal collectors, usually installed on the roof, that absorb heat from sunlight. This heat is transferred to water running through pipes in the collectors.
The heated water is then stored in an insulated storage tank ready for use. Solar water heaters utilise the sun’s free energy whenever possible, but most also have an electric or gas booster as backup. The booster kicks in to ensure you have hot water even on overcast days or at night when solar energy is unavailable.
A benefit of solar hot water is lower energy bills, since it reduces reliance on electricity or gas.
Solar also has a lighter environmental footprint. However, solar collectors work most efficiently in full sun. Supplemental boosting may be needed in cooler or low sunlight climates.
Upfront costs of installing a solar hot water system tend to be higher than conventional heaters. But this can pay off over time with savings on utility bills. Solar water heating works best when paired with efficient plumbing and water use habits.
How Electric Storage Tank Water Heaters Work
Electric storage tank water heaters operate by using electric heating elements to heat water stored in an insulated tank. When you turn on a hot water tap, hot water flows from the top of the tank while cold water enters the bottom. Here’s how the process works:
One or more electric heating elements are located near the bottom of the tank. When the water temperature falls below a set thermostat level, the elements switch on to heat the water.
Cold water coming into the system enters the bottom of the tank. As it’s heated by the electric elements, it becomes less dense than the cooler water in the tank. This causes the hot water to rise to the top while pushing the cooler water downward.
At the top of the tank is a hot water outlet pipe. When a hot tap is turned on, hot water exits the tank through this pipe due to gravity, flowing to the tap. As hot water is drawn out, incoming cold water refills the tank from the bottom to repeat the heating process.
Electric storage tank heaters provide a reliable and consistent source of hot water. But they can be less energy efficient than some systems since the tank requires continual heating. Proper installation and maintenance are needed to maximise efficiency and longevity.
Key Components
p>p>p>
Thermostat Operation
Electric storage tank water heaters use a thermostat to regulate water temperature. The thermostat is usually located near the top of the tank. It’s connected to a temperature sensor that monitors the water temperature.
You set your desired hot water temperature on the thermostat control panel. A residential thermostat is typically adjustable from 60°C to 75°C. The thermostat maintains this set temperature by automatically controlling the electric heating elements.
When the tank water cools below the set point, the thermostat switches on the electric elements to heat it back up. Once the water reaches the desired temperature, the thermostat shuts off the heating elements.
This on/off cycling occurs as needed to keep the stored water consistently hot. Having a properly calibrated thermostat is important to maximise efficiency and prevent overheating which can shorten the system’s lifespan.
Some high-end electric tank water heaters have digital thermostats with additional features. These allow you to programme different temperatures for peak and off-peak hours based on your usage patterns.
Comparing Electric and Gas Storage Tank Systems
p>p>p>p>p>p>p>p>p>p>p>p>p>
Maintenance for Storage Tank Systems
p>Regular maintenance is crucial for storage tank hot water systems to operate safely and efficiently. Here are some tips:
Drain and Flush AnnuallyDraining and flushing the tank removes built-up sediment that can lead to corrosion. Turn off power/gas, attach a hose to the drain valve, and open the pressure relief valve. Flush until water runs clear.
Inspect Anodes and Replace if NeededCheck the metal anode rod every 2-3 years. This rod attracts corrosion instead of the tank. Replace if it’s heavily corroded.
Check Valves, Pipes and FittingsInspect water supply lines and fittings for leaks, cracks or corrosion. Check and clean valves. Replace any worn parts.
Check Temperature and PressureUse a thermometer to ensure your thermostat is accurately maintaining water temperature. Make sure the pressure relief valve isn’t dripping, which can indicate excessive pressure.
Inspect Electrical ComponentsFor electric systems, check heating elements for mineral deposits and make sure electrical connections are tight. Consult a licenced electrician for any issues.
Clear Vent Pipingp>p>p>
When to Replace a Hot Water System
p>p>p>p>p>p>p>p>p>p>p>p>p>p>p>
Choosing the Right System for Your Home
p>p>p>p>p>p>p>p>p>p>p>
Conclusion
Having a reliable and efficient hot water system is a crucial part of any Australian home. The various types of systems each have their own advantages and downsides. Key factors to consider when selecting a hot water system include your climate, household size, hot water usage needs, and budget.
Storage tank systems provide a consistent supply of hot water but take up more space. Tankless heaters save space while heating water on demand, but may have limited flow.
Solar harnesses free sunlight but needs a conventional backup. And heat pumps use electricity to extract heat.
Understanding how your hot water system works allows you to maintain it properly. Signs like corrosion, leaks, and declining efficiency indicate when replacement may be needed. Work with a licenced plumber to install and service your system.
At Seven Hills Plumbing, we have over 15 years of experience installing and repairing all types of hot water systems. For reliable service throughout Sydney, contact us today to discuss the right hot water solution for your home.
