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Expert Advice from CDL Plumbing & Drainage on Choosing The Best Hot Water System in 2023

Once you understand the different types of hot water systems available, choosing the right one can still be difficult as they not only vary in price, but their running costs will vary as to how they work. Without some help, it’s not always a simple decision but let’s look at some simple advice that will help you choose the best hot water system for you in 2023.

Even choosing a replacement hot water system of the same type isn’t always simple and nowadays there are even more makes and models to choose from. Your choice can’t easily be undone without great cost so making a mistake isn’t an option, but luckily CDL are here to help once you’ve chosen your type of hot water system. Once you are satisfied your existing system is faulty beyond repair or just old and inefficient then the following will help you choose the best replacement hot water system.

Main Things To Consider When Choosing A Hot Water System

Once you know the 4 main types of hot water systems these are the main factors to consider:

  • Fuel Type (Electric, Gas or Solar)
  • System Size
  • Running Costs
  • Installation Cost
  • System Cost

Fuel Type

Electric heat pump hot water systems are an energy-efficient alternative to conventional electric systems. Instead of directly heating the water, they work by extracting heat from the surrounding air and using it to warm the water in the storage tank. This process consumes less energy compared to traditional electric systems, resulting in substantially reduced operational costs and environmental impact.

Heat pump hot water systems are suitable for various climates, including colder regions. However, their efficiency may decrease in extremely low temperatures. Like electric systems, they can also be affected by electricity prices and may contribute to greenhouse gas emissions if the electricity comes from non-renewable sources.

Tips for Properly Sizing Your Hot Water Heater

Getting the right-sized hot water heater is crucial to ensure you have sufficient hot water without wasting energy. Following these guidelines will help you to determine the appropriate size for your specific needs.

It’s generally accepted that each person will use around 50 litres of hot water per day, and in a storage system, it is good to have about 1.5 days capacity. As a guideline three-bedroom house can comfortably accommodate four people and so it should have a 300-litre tank.

This is quite a large page so I recommend the following 4 water system types be in expandable text boxes

Storage Water Heaters

If your storage heater is too small, you'll frequently run out of hot water. Conversely, a heater that is too large will be costly to operate since it'll maintain water temperature even when not in use.

For storage water heaters, sizing depends on the number of people in your household. The more occupants, the larger the storage tank required.

Continuous Flow (or Instant) Systems

An undersized continuous flow gas system might struggle to meet your hot water demands, especially when multiple hot water outlets are used simultaneously.

Sizing for continuous flow systems is based on the number of hot water outlets in your home rather than the number of people.

Solar Water Heaters

Solar water heaters are sized according to the number of people living in your household.

As the number of occupants increases, the storage tank and the number of solar collectors required also increase.

For the most accurate sizing recommendation, it's best to consult your water heater supplier. They can assess your specific needs and help you choose the right-sized system for optimal performance and efficiency.

Heat Pump Systems

Smaller tank sizes will almost always give the lowest energy use for heat pumps, but don't go smaller than your household actually needs or you may run out of hot water. Often heat pump sizing is based on very generous assumptions, leading to large tanks, which you may not need.

Running Costs

This could get very complicated very quickly without graphs, charts all sorts of comparisons let alone trying to predict the future. Suffice it to say, energy prices are massively on the rise but this article may help.

Gas is more efficient than electricity but it can cost more. Electric systems are cheaper as they have fewer moving parts and if you don’t already have gas then they will have higher installation costs too.

The cheapest system by far to run is solar, but it’s important to know that during poor weather it will normally need support with electricity. Solar prices are coming down and systems are now cheaper and more reliable.

A heat pump is incredibly efficient but it still requires electricity all the time and also suffers from inefficiency in very cold weather. Also, presently up-front costs are high but there are govt incentives.

Installation Cost

These will vary, but if you’re simply replacing your hot water system with the same type then this will reduce the labour time, as well as if it’s electric as there will be no gas plumbing to do. Solar and heat pumps generally have a reasonable installation cost due to their complex nature and access to roof space and outdoor areas. In short, an electric system is usually the cheapest to install, followed by gas if you already have the same gas water system type.

System Cost

Whilst these vary too, the answer is fairly simple. Solar and heat pumps will cost the most but are offset by their running costs. Gas continuous flow is more expensive than electric, but a gas storage tank system is comparable to an electric system.

The differences between brands are relatively minor, it’s the system size and power that will dictate its price. CDL doesn’t have any agreements with any of the top manufacturers like Bosch, Dux, Sanden, Rinnai, Steibel, Rheem, Solahart, Aquamax & Vulcan, so CDL can give you an unbiased recommendation on what is the best model at the time of purchase.


Much of the above will depend on actual prices like running costs and the whole system being supplied and installed. The only real way to compare is to get quotes from hot water experts like CDL. You can compare different models and different types as well as get unbiased information and recommendations from our team in Newcastle and Lake Macquarie. Ultimately, having some detailed quotes based on your needs will make choosing the right hot water system much easier.

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CDL Plumbing & Drainage are expert plumbers and gas fitters servicing Newcastle & Lake Macquarie from our Gateshead HQ. We have over 15 years of experience and specialise in all domestic and commercial plumbing, able to take on large-scale drainage projects. Fully qualified (Level 4), licensed & insured with free quotes. We have 2 teams of friendly and reliable plumbers with fully equipped vans.

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