Coating & Tank material in water heaters ( Stainless Steel, Copper, Glass-lined)

Nowadays, water heaters are a basic necessity at home. You need it to get hot water in minutes. 

Water Heater is a wonderful innovation, now you don’t have to wait to hours to get lukewarm, hot, steam bath and for other usages. In olden times people used various ways to get hot water before these geysers were introduced.

How water heater works?

Traditional methods lead to a lot of pollution burning sticks and then more than 30 minutes of waiting. It was quite annoying. After the introduction of a gas stove, people used to boil water on it during winter days.

Although, geysers made their way to the market and has become a saviour for a lot of people during cold days.

No one like to touch the freezing and chilly water when you can easily get boiling water within a few minutes. 

During winters we need hot water to bath, wash utensils and sometimes to laundry as well. Electric Geysers get you through it and work as an aide.

Whenever you go market, you will find a variety of options and the sellers are also in the race to sell their product, exaggerate things. Moreover, you need proper information regarding the heater before buying it.  

Furthermore, you buy it because one of your close relatives are using or might be your friends recommend you to get one. And in both cases, you may end up choosing the wrong Water Heater.

Different families require different heater depends upon various factors.

This article or you can say water heater buying guide will help you clear your doubts and choose a better electric geyser or gas geyser for your family.


The main purpose of buying a gas geyser is to get the hot water on time or whenever you need. The water gets stored in the heater for a time duration of 10 minutes to 1 hour. However, it sometimes leads to rusting. The storage time should depend on the requirement and need.

That is the reason, it is not easy to get rid of corrosion. You may also find that the input option is always on and these eater heaters are always full of it. Thus, making it cohesive to rusting. 

Keeping this in mind, the companies coat the inner surface of the heater to save it from corrosion. Thus, the companies paint it in the first place to make it more effective and better for the use of customers.

Materials used to make storage tanks in Water Heaters

There are different types of materials which are used to make storage tanks in geysers. 

1) Stainless Steel

2) Thermoplastic

3) Copper

Copper: Copper is corrosive in nature, and like it as a good conductor of heat. It leads to loss of heat which we cannot afford while we are using the heater. It requires an anti-corrosive coating. Copper material is used for making storage tanks and thus coating is a must. 

Stainless Steel: Comparatively, stainless steel is better than copper. As it provides better insulation. It is also corrosive in nature, in addition to, requires anti-corrosion coating just like copper.

Thermoplastic: This material is better as compared to copper and stainless steel. As it is non-corrosive but on the other hand, they are bad at providing insulation.  

It leaves us with the result that most of the companies go with the stainless steel material to make storage tanks. As far as, the insulation and anti-corrosive properties are concerned, it is the best material for Water Heaters.

Materials used for coating

1) Glass-lined coated inner tanks

2) Polymer Coating

3) Porcelain Enamel Glass Lined tanks

4) Vitreous Enamel Coat

5) Blue Silicone Enamel Coating

There are companies which provide the coated tanks which specified technology and they sell it in the market with a different name. Apart from the name, it is all the same. There is not much of a difference in the material and the benefits.

Many of the companies use polymer as a material for coating. All in all, as a protection from corrosion, polymer coating is used for storage tanks.

How does it work?

To know how things are done, get through this article and know for yourself, which materials are used for coating of storage tanks. Coating the stainless steel in the first place is a must. To protect the tanks from corrosion, coating is important.

The stainless steel tanks are coated with the glass powder. It is heated on the furnace to give it the glass coating as desired. To brief, it is an effective way or technology to give the glass coating to stainless steel storage tanks of the heater. 

Apart from glass, to coat the material, Polymer is used to save it from corrosion. Polymer is a synthetic material and many of the companies use it severely. Polymer coating is different from the glass coating and a different procedure is followed for this. But the objective is the same.


1) We know that glass is a bad conductor of heat, thus making it a good quality insulator. It is used together with stainless steel, gives the best protection from corrosion.

Water heater components
Source: Stevejenkins

2) Polymers are just like paints. A synthetic material and used it to protect the stainless steel from corrosion. Moreover, it comes with great insulation quality.

Now the question arises which one is better, Glass material coating or Polymer coating?

Polymer and Glass both are different material and both works differently and also possess varying properties. Glass coating is widely accepted and it is used by most of the companies. However, there are chances of any kind of damage to excessive usage. 

Theoretically, Polymer coating is considered better than the glass coating material. But it depends on the user experience.

How you are using it, the consistency. You have to change the coating after it is used much as the coating gets ruined after excessive use. 

Things to keep in mind before buying Water Heater

1) Ratings: Go with the 5 stars ratings. Check out all the details and ask the seller to tell you about the coating material and other important information related to it.

2) Warranty: Most of the companies give 2-3 years of warranty on their products and if within this duration something comes up then you can ask for exchange or you can also ask for free servicing. However, the description or user manual consists of all the information.

3) Insulation: It is advisable to get the information about the insulation quality. The insulation quality inversely varies, better the insulation quality less the heat loss. 

4) BEE Ratings: The geyser should have a good BEE rating, i.e., Bureau of Energy Efficiency ratings are important. 

5) Combination: Best combination for the heater would be a stainless steel storage tank along with glass or polymer coating. So, don’t get confused about which water heater to buy, as you know the parameters. 

6) Heating Element: After water tanks, the heating elements are a vital part of the geyser. It can likewise get damage due to a number of reasons. What’s more, when that occurs, the unit viably quits working. It can get replaced easily. 


Ultimately, you will buy the Water Heater which is in your budget and the one which has a longer warranty period as compared to others. Though there are a variety of options available in the market. You can easily get one of your choices.

Although, we tried to sum up all the relevant information to clear the troubled cloud hovering over you. This article consists of all the details, which you need to keep in mind while buying the Heater.

Parameters which are important to keep in mind before buying the product from the market:

1) Coating

2) Water storage timing

3) Storage tank material

4) BEE Ratings 

5) Warranty

6) Insulation quality

7) Number of people going to use the geyser

8) Joint families should buy a large water storage capacity water heater. As within a few hours, almost all the members use the geyser and thus there should be enough hot water supply for everyone in the family. 

Altogether, these things will make it perfect to help you get what you are looking for.

Thus don’t go with the choice of your friends and relatives, your decision should be based on the requirement and needs of yours. Keep in mind all the factors and all it needs proper ventilation.

There are different types of Heaters available in the market. One such is a gas geyser and the other one is an electric heater.

Gas Geysers runs using the LPG cylinder, and thus required to be fitted someplace with proper ventilation. As it releases heat. 

While on the other hand, electric geysers require quite some time to heat up the water.

It remains in the storage tank for hours and you can easily use it for cleaning, bathing, and for other purposes too. You can switch off the button after it gets heated up.

Michael Benedict
Electronics Engineer by education, blogger by passion. I review gadgets kitchen & home appliances. I focus on the quality of information rather than serving quantity. There are many new ideas generated all over the world every day and I research and share some of them here. You can connect with me at

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  1. Kindly,mention the costing of POLYMER COATED TANK over GLASS COATED TANK.which is economic??thanks for such a useful information.

    • A polymer coated tank is better than a glass-coated tank in case of corrosion resistance and it’s economical as well. You can get different rates on Indiamart from many sellers.


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