Water Heaters

Coating and tank material in water heaters (Glass lined, Polymer, stainless steel)

Buying a perfect water heater is still a task for most of us. Different brands offer different functions and features, which might confuse the buyer.

As every part of the product has its significance, its material & type plays an important part in the working. Every household has different requirements, based on which one needs to finalize the product. A good buyer guide will be very useful if you are planning to buy any product.

To help you out in some aspects we will be talking about coating & material used in storage tanks of water heaters.

Coating and tank material in water heaters
Table Of Content

Significance of Coating

Storage tank water heaters store warm water that can be used later. Now this storage time might vary as per your usage. Storage tanks in water heaters are almost always full. In this situation, corrosion is bound to happen.
Corrosion will degrade the water heater performance & reduce its life. So, to avoid corrosion the inner surface of storage tanks is coated with anti-corrosion material. This coating prevents corrosion.

Different material options in storage tanks

Following are the three common materials used in manufacturing storage tanks of Water Heaters:

  • Copper
  • Stainless Steel
  • Thermoplastic or Polymer
Also, Read

Let’s have a quick comparison of these three types of material:

Copper being a good conductor causes a lot of heat loss during the process, which is not desirable in the case of water heaters. Stainless steel, on the other hand, offers well insulation.
Thermoplastic again is not very good at insulation.

So based on heat loss, we will recommend stainless steel tanks as are a good option. Now if we talk about corrosion, which is also the main, factor affecting the water heater performance Thermoplastics being the non-corrosive will be a good option.
Copper & stainless steel both are corrosive thus require additional anti-corrosive coating on the inner layer of the tank.

 CopperStainless SteelThermoplastic
Heat LossHighlowmedium
Corrosive natureHighmediumlow
So if we compare & conclude a stainless steel tank with an anti-corrosive coating is a good option. Now let’s discuss more on the coating material.

Different material options for coating

The most common options available for anti-corrosive coating in the market are:
  • Porcelain Enamel Glass Lining
  • Glass Coating
  • Vitreous Enamel Coating
  • Blue Silicon Enamel Coating
  • Polymer Coating

The first four mentioned coatings are a different type of glass coatings. In which glass powder is fused with the metal surface using heat to create a mechanical bond between glass & metal. The detailed processes of all four are somewhat the same but still different. As the basic principle behind them is similar, get the glass coating on the metal. Glass coating protects the metal from corrosion.

Being a bad conductor of electricity, glass provides better protection against corrosion.

On the other hand, polymers are synthetic materials. They are more like paint on the metal surface. If we compare polymer coating and glass coating, glass coatings are more trusted. But theoretically, the polymer coating is better because of the high chance of damage in the case of glass coatings.


In a nutshell, a water heater with a stainless steel tank with polymer or glass coating is an ideal water heater. Better insulation of a stainless steel tank will lower the heat loss & anti-corrosive coating will save the water tank from corrosion.

Other than tank & coating material there are other characteristics too, based on which you can choose the ideal water heater for you. BEE rating is among them. Always choose the product with a 5-star rating. Also, choose the product with a longer warranty.

Sources: kitchenarenaWikipediahse.govKyodo

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Hi all, I am Pulkit Jain - Digital Marketer, Entrepreneur, Avid Traveller, Blogger and a big time Foodie. After completing my Engineering in 2016 and taking up a Job in marketing company, I think it was the best decision I've made so far. Working with some top brands in initial years of my career now I am a full time blogger and started my own Digital Marketing Agency - Your Digital Boat. Follow Me on - Facebook, Linkedin and Instagram

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