For any household considering investing in a tankless gas water heater, or for those who wonder what it is all about, it is important to understand what it is, the pros and cons of having one and which ones on the market are the best to go for. Let\u2019s start with what these are - in essence, it is a water heater that uses gas to heat water but doesn\u2019t have a storage tank for the water. It will heat the water when you run the tap or turn the water on, taking away the problem of having to wait for the water tank to fill before having access to hot water. Perhaps the biggest benefit of choosing a tankless water heater is its energy efficiency when compared to other products. You\u2019re not going to have a system constantly heating and re-heating a tank of water, even when you don\u2019t need it, instantly reducing costs to your energy bills and helping reduce the environmental impact. Our Top Picks Best Gas Tankless Heaters of 2020 Gas Tankless Heaters that are worth mentioning: Our Top 5 Gas Tankless Heaters We\u2019ve spent time reviewing the latest tankless gas water heaters on the market and put together five of our favourites, to help you understand what is out there and guide you to the best one for your property. 1. Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater The first on our list is this tankless water heater from Rinnai, a sleek, stylish designed product which has been given a metallic design to make it fit with many modern properties. The designers have not only thought about looks but function as well, with it being designed to save space and fit in far smaller areas when compared to some of the alternatives. In terms of energy efficiency, this is a concentric model with the possibility of PVC venting should you require it, all leading to a fantastic efficiency of up to 0.96 Energy Factor, as well as claiming to have ultra-low NOx emissions. The only real downside to this product is the concentric exhaust requiring some additional parts and so this adds to the cost. 2. Rheem RTGH-95DVLN Indoor Direct Vent Tankless Natural Gas Water Heater Let\u2019s start with the most important feedback - the energy efficiency, which is a great 95% on this model and that is why it\u2019s one of our favourites. It has been built with efficiency in mind, with its heat exchanger being made out of stainless steel to add to the energy efficiency. It also has some other interesting features that we feel make this tankless heater from Rheem stand out. Firstly, it has electronic controls which are easy to use and effective, helping with safety and energy efficiency. On top of that, it has been built to utilise a PVC two-pipe direct vent system and the manufacturers state it has freeze protection and low NOx emission. That is all sounding great so far but we do need to inform everyone that tests have shown it to be a bit on the noisy side and the maximum temperature isn\u2019t as high as some of the other models, though still good enough for most households at 120. 3. Rinnai RUC98iP Ultra Series Propane Tankless Water Heater We head back to Rinnai for the third tankless water heater on our list and the primary difference here is that it uses propane, as opposed to natural gas. It has been designed with the same metallic finish as the previous model so it will fit in nicely with most properties. Furthermore, it comes with a similar energy factor of up to 0.96 and as a result of the technology within, offers barely any NOx emissions, great news for all households. This system offers both options for venting - PVC and concentric, as well as a generous manufacturers warranty ranging from 1 year for labour, up to 12 years on the heat exchanger. This long-lasting product will repay your initial investment but we have found customers report that it can take up to one minute for hot water to appear, after turning on the tap, which could be frustrating for many. 4. Eccotemp i12-NG Tankless Water Heater This heater from Eccotemp truly is one of our favourites, particularly in terms of design. It has a modern, sleek design combining silver with a black glass front which incorporates a fantastic LED display and control system. Of all the products on the market, we think this one fits into almost any modern kitchen the best. The modern approach to design is mirrored in its energy efficiency and energy savings, starting up when required, so it is not constantly running and costing you money. Throw in some child-lock technology and automatic temperature controls and you\u2019ve got a great water heater. Sadly, the exhaust on this model can get quite hot, so you need to think about the correct installation and protection but whilst we are on the subject, it isn\u2019t the easiest to install anyway, so you may want to get help with it from a professional. 5. Gasland BE158 1.58GPM 6L Outdoor Portable Gas Water Heater The final product we recommend for you is a little different from the rest and that is because it is a portable gas water heater. Due to the fact it\u2019s an outdoor portable device, the guys at Gasland have thrown in a whole host of safety features that give you true peace of mind, including antifreeze, overheating protection and automatic controls on the water pressure. They have thought about what people want from a portable device and this meets the criteria, being a nice compact design and relatively lightweight, so transporting and mounting the heater isn\u2019t a problem, particularly with handy mounting brackets. It doesn\u2019t let you down on the energy efficiency front either, carefully designed to minimise fas consumption. One downside we did find was that the supporting instructions are somewhat lacking, so you may need to go with some trial and error before getting the right shower. Summary We hope this article has provided you with a strong overview of what a tankless gas water heater is and how they can be a fantastic addition to your household or even camper van for those travelling the country. As always with any water heater, filter or another kind of system, make sure you consider the usage, quality of water and infrastructure in place, before making a purchase. Once you\u2019ve done that, then check out our favourites and see whether they are the right fit for your property. Types of Tankless Gas Water Heaters Now that we\u2019ve briefly touched on what a tankless gas water heater is, we want to tell you about the three main types on the market and the differences between them, to help you make an informed decision. Condensing This type of tankless heater utilises a second heat exchanger that comes into play after the primary one, reuses the heat generated from the exhaust to heat more water. As a result, this increases the efficiency of the product, up to a potential 94%, as well as offering safer ventilation options. However, this model can cost more than other types so it is a delicate balance between cost and improvements in efficiency levels. One final consideration here is that it isn\u2019t the most efficient solution for short water draws and by this, we mean short bursts of water for washing your hands. So again, think about your water usage and whether this is important. Non-condensing The non-condensing heaters use a single heat exchanger to heat water when you run a tap or request it to do so, a technology that has long been used in Europe and parts of Asia. As such, they are known to be very reliable sources of water heating, with minimal issues and an efficiency of up to 85%. The main problem with this type of tankless gas water heater is that you will likely need to install additional vents due to the temperature levels of the exhaust, losing energy efficiency. Hybrid The hybrid condensing units are a newer system and so lack the availability of the other models, but they do have some very interesting advantages. Firstly, this unit utilises a small water container, using it as a reservoir of hot water and as a result, increasing energy efficiency, even when using them for short draws, such as washing your hands. They don\u2019t need as extensive ventilation as non-condensing, reducing the cost to purchase and install. Due to the relatively small group of companies producing these, you may find your choice limited and even then, you will generally have to go to a less well-known company, so make sure you check their build quality and warranty support. The Pros and Cons No matter what problem you\u2019re trying to resolve, the different solutions open to you will have both pros and cons. Gas tankless water heaters are no different and it is important to understand all of the implications before making a purchase. Pros There are plenty of pros to choosing these tankless water heaters for your property, whether that is a house, office or mobile home and we\u2019ve listed a few of them below for you: Instant hot water The purpose of tankless water heaters is that they offer hot water without waiting for a water tank to fill up or refill if you\u2019re using a lot of water. So you can say hello to on-demand hot water whenever you need it. Energy-efficient systems No matter which type of tankless heater you go for, they offer great energy savings and depending on the design, they offer energy-efficient units up to 96% efficiency, leading to great saving on your gas bills. Long-lasting It is our expectation that well maintained tankless units can potentially last up to 20 years, compared to roughly half that for tank units. So, despite the higher initial costs, these really do win in the long run. Reduced costs You will no longer have a water tank being heated up repeatedly to ensure there is hot water on standby, reducing the costs of your energy bills. Not only that, but they also offer a reduced impact on the environment, savings for you and the world. Size The tankless gas water heaters are far small than the tank equivalent because you are obviously ditching the water tank part. This means they are suitable for smaller homes, alternative properties and far easier to implement into your home water systems. Cons Despite the clear benefits of purchasing a tankless gas water heater, there are some cons that people should be aware of, as they may alter your plans: Initial cost The biggest setback to choosing this type of water heater is the initial cost of buying one. When we compare it with traditional heating options, you are looking at potentially double the price, if not more. Consider also the potential need for professional installation services and retrofitting and you can see the prices rise. Home modifications If your home is not set up for a tankless gas water heater, then you will potentially need to modify the gas systems, as well as making sure you have the appropriate ventilation. The vast majority will require work completed by a professional and some extra equipment fitted. Temperature fluctuations As a result of not having a tank of water pre-heated, customers who buy these products may notice fluctuations in the water temperature, particularly if you have multiple taps running at the same time or are in a high-usage property. However, you will come across different issues with water tanks for high-usage properties, so either way, you will see some issues. More equipment It is important to think about the type of water supply you have in your household and should it be hard water, then you will need to consider adding a softener into the system, which will add to your initial cost and affect the space needed for the entire system. Make sure you\u2019ve budgeted for this and it all fits.