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How Does An Instant Gas Hot Water System Work?

How Does An Instant Gas Hot Water System Work?

When it comes to installing water heaters, anybody would want to go for the type that provides an uninterrupted supply of hot water.

And that’s where instantaneous or tankless gas heating systems come into the picture, as they offer the consistency and efficiency that every homeowner desires. Also, they require minimal maintenance and are least likely to need a repair anytime soon, unlike those with tanks.

Now, you must be wondering what makes these systems so efficient. Hence, to make it all crystal clear, we’ll be discussing in detail about the way they work and all other related information that you should know before installing one.

Gas Metre For Hot Water System

Without further ado, let’s get straight to the point!

How Does Instant Gas Hot Water Systems Work?

This water heating system uses either electronic ignition or a pilot light to heat water whenever you need. Now, the means of ignition may be placed either internally or externally, but there must be sufficient ventilation to ensure that it works properly.

Note that during its installation, the system is connected through a separate pipeline to a tap for dispensing the hot water. When this tap is opened, a sensor in the system detects the water flow, as a result of which the gas burner is ignited. The water is then heated by the burner while flowing through a pipe commonly called a heat exchanger.

As such, the burner heats only the amount that you require at any moment instead of continuously heating a tank full of water, and the water slows down gradually as it flows. This implies that the hot water is supplied at a pressure lower than heating systems that come with a tank.

Considerations For Installation

Installing an instant gas water heating system requires considering various factors, which we’ll briefly discuss in this section.

1. Gas Supply

To install an instant gas water heating system, you must ensure your home has a connection with the gas supply line or an LPG cylinder.

In case you are not sure about the presence of a gas supply line or whether a connection can be established, you’ll have to contact a reliable plumbing service. They would provide you with all the related information and can also build the required supply line.

2. Size

Another vital consideration is the size of the heating system you’ll go for. Homeowners often end up buying a unit that is larger or smaller than what they need. So, it’s a must to keep in mind your needs while deciding on an ideal model.

Not only will this save you money on the purchase and the cost of running the appliance, but would also ensure you get optimum performance out of it.

3. Price

Price is also an important point to consider as the model you choose must be within your budget. These heating systems are generally a bit more expensive than the electric ones, but rest assured they will prove to be cost-effective in the long run.

4. Pressure And Temperature Valve

The majority of heating systems have a pressure and temperature valve to ensure that the high pressure or heat inside the system is released. But if it’s not installed properly, the tank may explode and the viewer may even be covered with drops of boiling water.

Here, you must note that some plumbing services establish a connection between the threaded drain and the valve outlet and fit the pipeline to the ground to transfer blasts safely.

5. Compatibility Between Metal Pipes

While getting a heating system installed, you must ensure that the metal pipes used in the system and the ones in your home’s existing plumbing system are compatible. For instance, if the system consists of copper or brass connectors and the house pipes are made from copper, installing the system would be easy.

But if your home has electroplated steel pipes, you must inform the professionals so that they use an electrical insulator. This will ensure that the two pipes being connected don’t cause any destructive load, which can weaken them or cause leaks.


There are lots of benefits of installing an instant gas water heating system, so let us take a look at each of them briefly:

1. Energy-Efficient

Since instant gas hot water systems don't have tanks, users can save a great deal of energy that would’ve been spent in maintaining the temperature of the water stored in the tank. Its burner runs only when you need hot water, and that’s when the appliance uses energy. This feature makes it an ideal choice for homeowners who prefer energy-efficient alternatives.

2. Unending Hot Water Supply

Being an instantaneous water heating system, it provides users with a continuous hot water supply.

This is the primary factor that puts the system at an advantage over traditional heaters with hot water tanks that can heat a limited amount of water at once. Moreover, once the pre-heated water is used up, the latter requires some time for recovery to ensure the fresh water is heated up.

If this happens while you’re taking a hot shower, you have no choice but to use cold water or wait for some time during this “refill.” But such chances are ruled out when you have an instant gas water heating system.

3. Reduced Emissions

Using a good-quality instant gas water heating system can substantially reduce the emission of greenhouse gasses such as CO2. In fact, they produce low emissions as compared to electric water heaters with tanks. What makes this possible is the use of LPG or natural gas in the instant gas water heating systems.

4. Space-Saving And Better Design

Instant gas water heating systems come in about the same size as any small suitcase and their compactness can be credited to the absence of bulky water tanks like in traditional water heaters. Furthermore,they enhance the visual appeal as the unit will not dominate the wall on which it is mounted.

5. Reduces Water Wastage

An instant water heating system heats water whenever you require, which ensures there is minimal water wastage during the time taken for the heated water to flow through the tap. Hence, it’s a perfect choice for all both commercial and residential purposes.

6. Flexible Installation

The small size of these systems makes them suitable for being installed almost anywhere. Plus, most of the brands provide models for both outdoors and indoors to meet different user requirements.

Hot Water Size Chart Gas

Final Words

We hope you enjoyed reading this guide on instant gas hot water systems.

We hope that by now, you must’ve formed a clear idea about how these systems work and the nitty-gritty of their installation. So, go ahead and choose a suitable one!

And once you have purchased a model, make sure to contact a good plumbing service for the installation. At the same time, keep in mind all the relevant factors we’ve mentioned in this regard.

If you feel there’s any problem that might affect the installation, don’t forget to discuss it with the plumbing professionals. They will surely be able to provide the right solution.

With that, we’ll take your leave. Bye, take care!