When a storage hot water system fails, most homeowners understandably start by looking at the replacement price.
But there is another question worth asking:
What is the new tank actually made from?
We recently replaced a hot water system for a customer whose existing steel tank had deteriorated badly.
The water had become noticeably brown, and corrosion inside the old system was an obvious concern for the household.
At the same time, the family had children experiencing skin irritation. We can’t say the hot water system caused a dermatological condition, but when you’ve got visibly discoloured hot water coming from a deteriorating tank, it’s completely understandable that the quality of the water becomes a priority.
Rather than simply replacing the failed system with another inexpensive tank of similar construction, we recommended moving to a stainless steel hot water system.
Here’s why.
What’s Inside a Conventional Steel Hot Water Tank?
A traditional storage hot water system may appear to be a simple metal cylinder, but manufacturers need to protect the steel tank from constant exposure to hot water.
One common construction method uses a carbon-steel cylinder lined internally with vitreous enamel.
Vitreous enamel is essentially a glass-like coating bonded to the metal. Its job is to provide a barrier between the water and the steel underneath. Manufacturers also commonly use a sacrificial anode inside the tank to provide additional corrosion protection.
That anode is designed to corrode gradually so that the tank doesn’t.
Rinnai, for example, describes the anode in its conventional storage systems as a metal rod that slowly corrodes over time to help protect the tank from rust.
It’s a proven method and there are plenty of good-quality vitreous-enamel storage systems on the market.
But no protective system lasts forever.
What Happens as a Steel Tank Ages?
Over years of heating, cooling and storing water, corrosion protection becomes increasingly important.
The sacrificial anode is consumed over time. The internal lining can also deteriorate or become damaged.
Once water is able to attack exposed steel, corrosion can begin.
Eventually that can contribute to symptoms such as:
- brown or rusty-looking hot water
- sediment accumulating in the tank
- corrosion around the system
- leaking from the cylinder
- eventual tank failure
This is one reason maintenance and the quality of the original hot water system matter.
It is also why the cheapest replacement isn’t necessarily the best long-term decision.
What’s Different About Stainless Steel?
A stainless steel storage cylinder takes a different approach.
Rather than relying on an enamel coating to separate ordinary steel from the stored water, the cylinder itself is constructed from corrosion-resistant stainless steel.
Stainless steel contains chromium that forms a thin protective passive layer on its surface, giving the material its characteristic resistance to corrosion.
That removes one of the major differences found in conventional enamel-lined systems.
Some current Rheem stainless steel electric water heaters, for example, use stainless steel cylinders and water fittings and do not require a sacrificial anode. Rheem specifically lists the lack of an anode as reducing maintenance and service requirements. Selected models also carry a 12-year cylinder warranty.
AquaMAX similarly uses stainless steel cylinders in its premium gas storage range, with its G390SS currently carrying a 12-year cylinder warranty.
Does Stainless Steel Mean It Can Never Corrode?
No material should be sold with an absolute guarantee like that.
Stainless steel is highly corrosion resistant, but its suitability still depends on factors including the chemistry of the local water supply.
Rheem itself advises that its stainless steel water heaters aren’t recommended in some areas and provides a water-quality suitability guide for installation.
That’s why we look at the property and installation rather than simply declaring one tank material universally better.
Where the water conditions are suitable, however, stainless steel gives us a very attractive option because we’re no longer relying on the same enamel-lined mild-steel construction and sacrificial-anode protection used in many traditional tanks.
The Cheapest Tank and the Cheapest Hot Water System Aren’t Always the Same Thing
This is where we think homeowners need better information.
If one hot water system costs less today but deteriorates substantially sooner, the original purchase price doesn’t tell you the real cost of owning it.
Replacement means buying another system, removing the old one, paying for installation again and dealing with the inconvenience of another failure.
That’s why, when we’re recommending a system, we’re interested in more than the number on the price tag.
We look at:
- tank construction
- expected maintenance
- warranty
- household hot-water demand
- water quality
- energy source
- installation conditions
- likely long-term value
Sometimes a conventional enamel-lined tank will still be the right answer.
In other situations, spending more for a quality stainless steel unit makes much more sense.
A Better Hot Water Recommendation Starts With the Household
The customer we mentioned earlier could easily have been given another cheap steel storage system.
It would have restored their hot water.
But it wouldn’t have addressed the reason we were uncomfortable simply repeating the same solution.
Their previous tank had deteriorated, the hot water had become brown and the family wanted confidence in what was replacing it.
A stainless steel system gave us a fundamentally different tank construction and a better fit for what that household actually cared about.
That’s the way we believe hot water should be approached.
Not:
“What is the cheapest unit we can put here?”
But:
“What system makes the most sense for this home over the years it’s going to be used?”
If your hot water system is starting to rust, leak, produce discoloured water or simply reach the end of its life, speak with RJT Plumbing & Gas before replacing it like-for-like.
There may be a better option.
RJT Plumbing & Gas can assess your existing system, household requirements and installation and recommend a hot water system designed around your home rather than simply what’s cheapest on the day.
