Which Hot Water System Is Best?

Which Hot Water System Is Best?

What to know about hot water systems for your home

A working hot water system is an essential part of a comfortable living environment, especially for during winter. However, knowing the right hot water system for your home can be quite challenging because there is so much to consider. Do you know if you want a gas, electric, solar or heat pump system? Will your water supply be from a storage tank or continuous water flow? How big will your tank be? How much do hot water systems cost? This article will provide you with all of the information you will need to know about the best hot water systems to suit your home.

What type of hot water system should you use?

There are a number of different types of hot water systems to choose from, such as:

  • Electric.
  • Gas.
  • Instant.
  • Heat pumps.
  • Solar.

Here is some of the main information on each of these systems that will help you understand what hot water system is the best for your home.

Electric water heating

Electric hot water systems are a popular choice among many Australians. They can be installed quickly if an existing system is getting replaced, for a low cost both indoors or outdoors. They are also inexpensive to purchase however, they can be more expensive to run, especially at the full day rate. You can purchase a storage or instant electric water heating system.

Gas hot water systems

Gas hot water systems have been around for some time now and are a common part of many households. There are a number of different storage and instant gas hot water systems you can purchase. These systems are generally cheaper to run than electric water heaters but have a worse carbon footprint.

Newer models have become more eco-friendly in recent years with natural gas and LPG models. LPG models are one of the most cost-effective options due to their heating value. Gas systems can be installed in a short amount of time if an old system is to be replaced, for a low cost and have a quick reheat time.

Instant water heaters

These systems are also commonly referred to as continuous or tankless water heaters because they do not require a storage tank for a water supply. Instant electric hot water systems only heat up the water you require, which ultimately lowers the cost of running the system as the amount of electricity or gas used to heat the water is reduced.

This also prevents any energy wasted heating the water when it isn’t being used. Due to their compact design, these systems are great for smaller areas, like apartments or offices but are still installed in a number of homes also.

Heat pump hot water

This system works by drawing out heat from the air to heat up stored water. Heat pump compressors can be installed indoors, but work best in well-ventilated areas so they are often installed outdoors. These heaters have high energy efficiency, low environmental impact and are a practical renewable energy option for water heating. Heat pump hot water systems are suited to warmer climates but can be installed with a booster for colder areas.

Heat pump heaters often have a high initial cost but most systems are eligible for a Small Scale Technology Certificate (STCs), which is a government initiative that helps lower the purchase cost of heat pumps. You can have an integrated, split or retrofitted heat pump hot water system installed into your home.

Solar hot water system

Solar-powered hot water units have a great eco-footprint and have a significantly low running cost. The installation process can be more time consuming as the builder will need to see the house plans to find the best location for the panels. The upfront cost is quite expensive but can be lowered from government incentives and rebates.

What water tank should you have for your water heater?

If you want to have a water storage facility for your water heating system there are a number of things you should consider, including:

  • Tank size – knowing what size hot water system do you need varies from the number of people using the facility, number of areas that require hot water.
  • Area of installation – best installed in a sunny or well-insulated spot to maintain quality of heating.
  • Tank type – stainless steel tanks are more expensive but have a longer lifetime.
  • Maintenance – to ensure your tank works for as long as possible, get a professional hot water system service.

Your hot water system specialists

If you are looking for a professional hot water system service across Brisbane, Logan, Redlands and the Gold Coast get in touch with Ryan Old Plumbing. We have a team of fully trained and licensed plumbing experts who have years of experience installing, repairing and replacing a wide range of water heater types, brands and models. You can rely on our efficient and cost-effective service to provide you with a solution that will meet your hot water system requirements. Contact us today!

Common Instant Gas Hot Water System Problems

Common Instant Gas Hot Water System Problems

When it comes to hot water in your home or workplace, you likely don’t think too much about how it works or what it does – you just turn on the tap and hot water comes out. And we don’t blame you

Having hot water is great in more ways than one – a long hot shower after a big day at work, using the dishwasher or just turning on the hot tap in the kitchen to wash your coffee mug – but what do you do when it isn’t working as it should?

Hot water issues can be disruptive in a variety of ways, not just when you want to run a nice warm bath after a long day. So, if you have an instant gas hot water heater and it is causing problems, keep reading to learn more. If you require further assistance, call Ryan Old Plumbing on 1300 055 940.

How does an instant gas water heater work?

An instant gas hot water heater, also known as a tankless, instantaneous or continuous flow system, only heats water as and when you need it. They have either a pilot flame or electronic ignition and water is heated by a gas burner as it flows through a coiled pipe, otherwise known as a heat exchanger. When you turn on a hot water tap, the gas burner starts up and heats only the water that is needed at that time.

how instant gas hot water work

  • Learn more about gas hot water systems here.
  • Learn more about instant hot water systems here.

What benefits does an instant gas water heater offer?

Instant gas hot water systems offer a huge variety of benefits, including:

  • Reduced amounts of wasted water.
  • Highly efficient systems.
  • Save energy and are more eco-friendly than many other choices.
  • Generally compact, so can fit in a variety of spaces (including small apartments or workspaces).
  • Both flued and unflued options are available.
  • Can be installed both indoors and outdoors.
  • Less lag time for water heating.
  • What are common instant gas hot water system problems?

What are common instant gas hot water system problems?

Although instantaneous gas hot water systems have a range of benefits, they do have some common issues too. The following common instant gas hot water problems are:

No hot water

If you don’t have any hot water at all, check the following 3 things. If you still don’t have hot water, call a hot water plumber.

  • Check that the system is plugged into the electrical outlet and switched on.
  • If your instant hot water system has a controller, double-check that it is on and the temperature is correct.
  • Check any gas appliances in your home to see if the gas is flowing – if they work, the gas supply isn’t the issue. If they are not working, you have hopefully found your issue – check your gas valve meter and call your local gas provider for further assistance.

The pilot light will not ignite

If your pilot light will not ignite, remember that a feature of instant gas hot water systems is that they require moderate to high water flow to ignite a pilot light. Therefore, run your hot water tap for a few minutes to see if this starts it.

Water is lukewarm

A faulty thermostat or a faulty diaphragm can cause lukewarm water to replace hot water.

Water is sporadically hot and cold

If you are finding that your water is sporadically hot and then cold, this is a problem many instant gas hot water systems experiences. There are a few things that can cause this including:

  • An undersized gas bottle can result in not enough gas getting to your system.
  • A faulty showerhead or a restrictor may be affecting the ability of a tap to register as a ‘hot water tap’.
  • The gas meter diaphragm may be faulty.

Producing less water and/or lower water pressure

If your instant gas hot water system is not producing as much water as it should, or the water pressure is lower than it should be, there are two main issues that it could be:

  • A broken or faulty thermostat.
  • The strainer valve may be blocked on the cold inl>

If your water is lower in pressure, this can be related to the pilot light. Remember however that instant hot water systems, in general, supply water at a lower hot water pressure than storage alternatives.

What to do with instant gas hot water system problems?

If your instant gas hot water system is experiencing any issues, call a professional such as Ryan Old Plumbing and they can assist. Remember, choosing to do the works yourself can void your insurance and any warranties you may have, and won’t guarantee the job is completed correctly. Always speak to the local plumbing experts!



What size hot water system do I need?

What size hot water system do I need?

Hot water is a crucial part of Australian life, from showers and baths to dishwashers and washing machines. But how do you know what hot water system size is best for your needs?

With so many hot water options on the market, you would be excused if you find it all a little overwhelming. Keep reading to find out more and if you would like further help, give Ryan Old Plumbing a call on 0488 856 880.

What are the different hot water systems available?

There are two different types of hot water systems and four different types of hot water service (confusing we know)

Hot water system types

  • Storage hot water system: also called tank systems.
  • Instantaneous hot water system: otherwise known as instant, tankless or continuous flow hot water systems.

Hot water service

What are the daily hot water demands for homes?

The average daily hot water needs of different households according to Energy Rating include:

Number of people Daily hot water demand (in Litres) Approximate size of storage tank needed (in Litres)
1-2 120 160 – 250
3-4 200 250 – 330
5-6+ 300 400+

What factors do I need to consider?

There are a range of factors to consider when looking at a hot water system and the size you need:

  • Would you like storage or an instant hot water heater?
  • How much space do you have to house a hot water system?
  • Do you have a preferred hot water brand?
  • How many people will be using the hot water heater?

One person generally uses about 50L of hot water a day.

  • When will everyone be using hot water? Will it all be at the same time, or at different times of the day?
  • How many showers are completed a day? When do they occur? E.g. morning, night, both?
  • How many hot water outlets do you have?
  • Do you wash your clothes in hot or cold water?
  • Do you have a dishwasher? How often do you use it?

How do you size a hot water system?

There are a few things to sit and look at when sizing a hot water system, including:

  • Storage hot water heaters: These hot water units are sized according to how many people are in your household. Remember, the more people that live in your house, the larger the storage hot water system will need to be.
  • Solar hot water systems: Just like storage hot water heaters, and sized in accordance with how many people like at your house.
  • Instant hot water units: These hot water systems are sized in accordance with how many hot water outlets you have in your home. The more outlets you have, the bigger the system you need.

water heating unit sizes

There are a few other points you should consider, such as:

  • If you choose a hot water system that is too big, you will be paying for water that is being heated and stored and you aren’t using it.
  • If you choose a hot water heater that is too small, you will run out of hot water regularly.
  • If you decide on an instant hot water system, and it is too small, you will not be able to get hot water from multiple hot water taps at once.

What size hot water system do I need?

The following is a guide only – we always recommend speaking to a qualified hot water professional such as Ryan Old Plumbing for further information.

Electric storage hot water systems

Off-peak Peak rate
Number of people Capacity (Litres) Number of people Capacity (Litres)
1-3 160 1 25
2-4 250 1-2 50
3-6 315 2-3 80
5-8 400 3-5 125

Natural gas and LPG hot water systems

Storage Continuous flow
Number of people Capacity (Litres) No. of outlets at one time Flow rate (Litres/minute)
1-3 90 1 16
2-4 130 2 20
3-5 170 2-3 24
4-6 200 3+ 32
5-9 260

Solar hot water systems

Number of people Hot water required

(Litres per day)

Approximate tank size Collector area (m2)
1-2 120 180 2
3-4 200 300 4
5-6 300 440 6

Information contained in the above three tables courtesy of Sustainable Energy Authority Victoria.

Heat pump hot water systems

Less than 200L (Small) 200 – 300L (Medium) 300L+ (Large)
Small home or apartment Average-sized home Large home
1-2 bedrooms, 1 bathroom 3 bedrooms, 1 bathroom 4+ bedrooms, 2+ bathrooms
Maximum of 2 people Maximum of 3 people 4+ people
Not generally suited to off-peak tariffs May not be suited to off-peak tariffs, some can run on restricted peak tariffs though Restricted hours and off-peak tariff are possible.

Information for the above table courtesy of Energy Rating.

Suggested hot water system options

In general, a solar hot water system is the most efficient option currently available on the market and the cheapest to run. If this is not an available option to your household though, a few other choices include:

  • Small household: 1-2 people. Small gas storage hot water system OR a gas or electric instant hot water system.
  • Medium household: 3-4 people. Heat pump hot water system OR continuous flow or storage gas hot water heater.
  • Large household: More than 5 people. Large heat pump hot water system, gas storage hot water heater or multiple continuous flow hot water systems (not that economical).

A family of four

For reference, if you are a family of 4 with 2 adults and 2 children, you would approximately need:

  • Electric hot water system: A 250 – 315L hot water storage tank for off-peak or a 125 – 160L tank for an instant system.
  • Gas hot water system: A storage tank of around 135 – 170L, however, there are alternative instantaneous options available too.
  • Solar hot water system: Around 4mᒾ of solar collector area and a 300 – 360L tank.
  • Heat pump hot water system: A 270 – 315L tank.


How long do hot water systems last?

How long do hot water systems last?

Hot water systems are a huge part of our everyday life, from showers to dishwashers to filling the laundry sink. A lot of the time we don’t even realise the reliance we have on hot water heaters, but they play a crucial role in more ways than one.

But, do you know the average lifespan of your hot water system? When you think about it, it runs 24 hours a day, 7 days a week and has to work at the drop of a hat. What’s your lifespan guess?


Although it may sound a little confusing, there are two different types of hot water heaters and four main types of hot water service.

Types of hot water systems

  • Instant hot water: otherwise known as continuous flow, tankless or instantaneous hot water heaters
  • Storage hot water: otherwise known as tank hot water heaters

Types of hot water services


There are four major aspects that affect how long your hot water system will last for:

  • Type.
  • Quality.
  • Usage.
  • Water quality.


In general, hot water systems last around 8 – 12 years. To be more specific:

  • Storage hot water: Enamel and glass-lined tanks last 5-10 years, whereas stainless steel and copper last 7 – 10 years.
  • Instant hot water: Last longer than storage systems, usually up to 20 years.
  • Heat pump hot water: 10 years (approx).

Always check the warranty of the hot water system you are buying, to ensure it is sufficient length for the type you are purchasing.


Keep an eye out for any of the following signs and symptoms, as they may be indicating it is time to replace your hot water system:

  • Age: If your hot water system is 15-20 years old, it is likely that it is in need of replacing.
  • Noise: If your hot water system is making a lot of noise, such as hissing or sizzling, this is a sign it may need to be replaced.
  • Provision of hot water: If your system is no longer producing reliable hot water, this can be a sign it may need replacing.
  • Corrosion: If you are finding that there is rust and/or sludge around the fittings, this corrosion can indicate a need for a replacement.


There are a few tips and tricks that you can implement to help your hot water system last longer:

  • Have a hot water professional complete regular servicing.
  • Always follow the manufacturer’s maintenance recommendations.
  • Keep an eye on the sacrificial anode.
  • Check the temperature and pressure relief valve (TPR).
  • Give Ryan Old Plumbing a call if you require any assistance with your hot water heater, or for any other plumbing needs today!


Trade-in for Solar Hot Water System Offer

Save $400 on your new hot water system

Need a new hot water heater?

You can be eligible for a $400 rebate if you trade in your old water heater for a new Rheem Hiline or Loline Solar Hot Water System or Heat Pump (300 litre or above). We are Rheem solar specialists dealers and can install a new hot water system or replace your existing system and help you claim the applicable incentives. Contact us today for more information.

Rheem Promotion for Solar Hot Water Heater

Read more:Rheem Solar Promotion

How can you take advantage of this great hot water trade-in offer?

The trade-in offer is applicable on the following systems of 300 litres and above:

  • Rheem Solar Stainless Steel Roof Systems – 52H and 52L with L, NPT and CSA2007 Series Collectors
  • Rheem Solar Electric Boosted Ground Systems – Loline SS Direct Series, VE Direct NPT Series and VE Direct CS07 Series
  • 52D and 52C with NPT Series Collectors
  • Rheem Heat Pump Systems 551 and 554 Series Systems – MPi and HDi Models

You can also claim Small-scale Technology Certificates (STCs) and rebates offered by the state and federal government. Our hot water plumbers can help you with this great hot water system trade-in offer and the applicable government incentives. Speak to our team today to find out more.


  • The Trade-In offer is Point of Sale discount offer on a selected range of Rheem products. It is NOT a redemption or Cash Back offer.
  • Offer not available with any other offer relating to Rheem or the participating products.
  • The promotion commences on 01/09/2020 and ends at 11:59 pm AEDST on 30/11/2020

Benefits of Solar and Heat Pump Hot Water Systems

  • They use less energy than gas and electric hot water heaters.
  • You can save on your utility bills.
  • They last longer than conventional water heaters.
  • They can increase the value of your home.
  • The gas and electricity prices will continue to rise in the coming period and it is better to switch to solar or heat pump hot water system.
  • The savings on utility bills can offset the initial cost of the water heater.
  • They use energy from the sun – they reduce your carbon footprint and are an environmentally friendly water heating option.

What to do if your hot water system is flood affected?

Is it safe to use appliances which have been submerged in water?

If your hot water system or any other electric or gas appliance is affected by the flood or water, you must contact qualified and licensed plumbers so they can inspect the extent of the damage and assess if it is safe to use.

The appliances may be damaged extensively by the flood and any attempts to use the damaged equipment can cause present a danger. If your hot water system is affected by floodwater, contact a licenced plumbing professional before trying to use the system.

What to do if your hot water system bursts or is affected by a flood?

  • Turn off the water supply to your water heater
  • Switch off the gas/electricity supply to the hot water system
  • Remove furniture and other items from the water damaged areas

We have wealth of knowledge and experience handling equipment affected by the flood and fixing hot water system issues. Our plumbers will assess your damaged hot water system and help figure out if it needs to be replaced or thrown away.

What should you do before turning on the hot water system?

  • Any hot water system which uses electricity and is damaged by flood must be inspected by a licensed plumber prior to reuse.
  • It is important that appliances are isolated from the electrical supply before any work is conducted on them.
  • Your plumber will test the appliance and suggest the recommended course of action.

What should you do before turning on the gas connection in your household?

  • The gas appliances, meters or regulators damaged by flood must be inspected by a licensed gas fitter.
  • The appliances connected to gas should be isolated from the gas supply before any work is conducted.
  • Your gas fitter will issue a gas compliance certificate and restore the gas supply once corrective works are carried out.

Why should you REPLACE the appliances damaged by flood?

The water damaged appliances need to be replaced as:

  • The electrical components like fan motors, pumps, circuits may be irreparably damaged.
  • Even if the appliances are working, using them is highly dangerous and the appliances will have a limited lifespan as the circuitry can be damaged by water.
  • For gas appliances, the silt from flood water can get lodged under gas valves, burners, and injectors. Consequently, the appliance will have poor combustion and unreliable operation. The blockage in the appliance can shut off the gas supply leading to gas leaks or explosive ignition.

Rinnai plumbing and gas appliances that must be scrapped if affected by a flood

Rework is not permitted on these models and they must be scrapped if damaged by a flood.

Hot Water Systems

  • Gas Continuous Flow Hot Water – Infinity, Builder, Enviro, Heavy Duty Series and Solar Boost S20, S26 and S32 models
  • Electric Storage – Hotflo, Flowmaster and QRE series
  • Heat Pump – EHP32 Heat Pump module and Enviroflo Integrated Series
  • Gas Boosted Solar Systems
  • Electric Boosted Solar Systems (Rinnai Sunmaster and Prestige)
  • Solar Controller and Pump Module (Split Systems)
  • Solar Collectors

Other Rinnai Appliances that must be scrapped once water damaged

  • Gas Flued Heater
  • Gas Portable Heaters
  • Electric Panel Heaters
  • Ducted Gas Heating (internal and external)


  • Gas Clothes Dryers

Reference – https://www.rinnai.com.au/blog/victorian-government-announces-solar-rebate-scheme-2/

TMV vs Tempering Valve – What’s the difference?

When you turn your hot water tap on, you expect hot water to flow out. Whether it is a shower, bath, kitchen sink or laundry basin, water at a particular temperature will always run from the faucets in your home or workplaces. But how does that occur?


Tempering valves and TMVs are the devices responsible for ensuring that the water that comes out of your tap is safe and at the right temperature. But, what is the difference?

Tempering Valve

What is a tempering valve?

A tempering valve, which is also known as a hot water mixing valve or a hot water tempering valve, is either a 2-inlet or 3-inlet mixing valve which is adjustable and activated by temperature. It mixes both hot and cold water together to achieve a desired temperature, in order to regulate the temperature of hot water that flows from outlets in your home.

What does a tempering valve do?

A tempering valve has a temperature sensitive element which focuses on adjusting the mix of hot/cold water depending on two factors:

  • What the tempering valve adjustment is.
  • What the water temperature is for any incoming water flow.

The mixing valve is a sliding component that is found in the tempering valve, ensuring the correct ratio of hot to cold water is being allowed to flow through. A tempering valve usually controls the temperature within ±3%.

What temperature is a tempering valve normally set at?

According to Queensland legislation, hot water is to be heated to a minimum of 60°C to prevent the growth of bacteria such as Legionella. A tempering valve ensures that hot water flows from taps at a maximum temperature of 50°C.

Thermostatic Mixing Valve

What is a TMV?

A thermostatic mixing valve, which is also known as a TMV, is a tool that combines hot and cold water together to maintain a specific water temperature when sending water through a faucet.

What does a thermostatic mixing valve do?

A TMV mixes both hot and cold water together so it is a particular temperature (within 1℃ +/-) so it can be sent to different water outlets. The temperature is generally prearranged by a tradesperson or a qualified plumber, and the TMV element that responds to thermal activity alters the levels of hot and/or cold water to ensure the correct temperature.

According to National Plumbing and Drainage Standard AS/NZS 3500.4: 2003, some water installations are not permitted to deliver water at a temperature higher than 50℃/45℃, which is why a TMV is installed – to assist with temperature regulation.

What temperature is a TMV normally set at?

Thermostatic mixing valves are generally set so hot water flows from a faucet at 45℃.

What is the difference between a TMV and a Tempering Valve?

Although TMVs and tempering valves get regularly mixed up, they are actually two separate devices. They both mix hot and cold water together to achieve a specific water temperature, but there are a few notable differences:

  • A plumber must have the appropriate TMV licence to install a TMV.
  • Tempering valves are not as quick as TMVs to respond to temperature changes.
  • TMVs last longer than tempering valves.
  • Tempering valves are cheaper than TMVs.
  • TMVs will generally get repaired, not replaced.
  • TMVs require inspecting every 12 months, in accordance with AS4032.3.

Thermostatic mixing valves are required by law in the following locations, due to the possibility of high risk people being present (such as the elderly, sick or children):

  • Hospitals.
  • Schools.
  • Aged care facilities.
  • Nursing homes.
  • Childcare facilities and afterschool care.
  • Respite centres.
  • Hotels.
  • Shopping centre bathroom facilities.

If you require further assistance with tempering valves and TMVs, give Ryan Old Plumbing a call on 0488 856 880.