Photograph of a steel water tankWater Pressure Tank Life Expectancy
Water Tank Replacement Guide & Age De-Coder

  • POST a QUESTION or READ FAQs about the typical life of a water pressure tank or water storage tank, and about when & how to replace a water tank

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Water tank life, water tank replacement.

This article explains how long a water tank is expected to last (it varies) and we describe how to decide when a water tank needs to be replaced - advice about what to do when things go wrong, such as finding air and water leaks and the process of deciding to replace a water pressure or water storage tank.

We also discuss where to put the water tank in relation to the pump and pump control switch. And we provide a water tank age decder as well as a Table of water tank brands, warranties, warranty periods. Table of Water Storage Tank Materials, Life, Warranty Period. Steel Water Tank Rust Perforation. Where to Locate the Replacement Water Pressure Tank.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

WHEN TO REPLACE WATER TANKS - When do you need a new water tank?

Severe corrosion and leak at a water storage tank (C) Daniel Friedman

How Long Does a Water Tank Last?

The life expectancy of a water storage tank or water pressure tank depends on at least these variables:

When an older type (non-captive-air) tank needs replacement (for example because it has rusted through and has perforations leaking water or air, or if adding air frequently becomes a hassle, you'll want the newer type of "captive air" or "bladder" tank.

If your tank looks like it has leprosy, if you see water streaming down its side from a "pinhole" leak, it may be possible to make a temporary emergency repair using a rubber washer and screw.

Your hardware store sells special screws for this purpose. This is only a stopgap measure. You need a new tank.

Various types of tanks uses in and around buildings are identified and explained below, including water pressure tanks, water storage tanks, range boilers for hot water, indirect fired hot water tanks, expansion tanks in attics, basements, and on heating boilers, oil storage tanks, rooftop tanks, cisterns, water pressure booster systems. We also discuss when to replace water tanks.

Table of Water Storage Tank Materials, Life, Warranty Period

[in process, suggestions welcome]

Water Pressure Tank Life & Warranty Comparison Summary by Manufacturer & Tank Type

Water Tank Type Rated Life or Warranty Comments
Amtrol, Well-X-Trol internal bladder, pre-pressurized Warranty: 7 years Product range, multiple sizes [7]
AquaTanks, polyethylene Warranty: 25 years New Zealand, export, stackable tanks, 295L to 31,000L, above ground & underground, various colours [9]
Flexcon Well-Rite, Challenger (butyl internal bladder), FlexLite, Flow-Thru, Jet Rite, FLEX 2 PRO and InWell brands Warranty: 5 years U.S., Canada, Mexico [10]
Flotec 35-Gallon internal bladder Warranty: 5 years # FP7120
Lochinvar glass lined water storage tanks Warranty: 5 years Thse [3]
Norwesco plastic aboveground water storage tanks Warranty: 3 years From date of manufacture. These tanks are used for chemical storage, not solely for water. Tank life when used for water storage may differ than when storing other chemicals. For water, these tanks meet FDA specifications for storage of potable water [2]
PVI® Storage Tanks (water heaters), glass lined Warranty: 5-20 years

AquaPLEX® engineered duplex alloy, standard tank warranty is 10 years with a 20-year option.

NICKELSHIELD® nickel-plated tank, standard tank warranty is 10 years with a 20-year option.

POLYSHIELD® polymer-lined tank, standard tank warranty is 5 years with a 15-year option.[4]

Underground plastic water tanks, polyethylene tanks, using some polypropylene or EPDM components Warranty often extends from date of manufacture, not installation Selected and installed per instructions does not void warranty for this tank type. Installing under a driveway voids warranty.
Utilitech 86-Gallon vertical, bladder, interior coated Warranty: 5 years # LPT-86
Same for smaller models
Water Worker 14GAL Horiz Pressure Tank Warranty: 5 years #HT-14HB (Sears)
Wellmate Composite Water Tanks, by Pentair, internal bladder, Residential application Warranty: 5 years from installation No steel components. [5]


Watch out: in collecting water tank warranty and life expectancy data we found that the variety of tank types and tank uses produces a wide range of data. When comparing tank life expectancy or warranty be sure you are comparing tanks intended for the same application

In our experience internal bladder water pressure tanks last well beyond their warranty period. An OPINION guess woudl be 10-20 years is average for these systems.[1]

In our experience galvanized steel water pressure tanks, nearly all of which contain some sort of internal coatings, last beyond their warranty period. We've seen tanks fail in five years (aggressive water, new modern thinwalled tank, possiblyi with a defective internal coating, and we've seen older, thick-walled, well-coated galvanized steel water pressure tanks last 25 years or longer.

We do not have long term experience with fiberglass or plastic type water storage tanks but in our OPINION expect their life to be 20-25 years or more if protected from UV (for some plastics) and from mechanical damage.


Steel Water Tank Rust Perforation & Emergency Tank Repairs

Photograph of a steel water tank

This steel water storage tank is leaking. When you see damage like this on a water tank, the perforation has rusted through from inside the tank. A tank that looks like this needs to be replaced.

Watch out: don't poke at rust like this on a water tank - you are likely to change a slow seep or drip into an immediate catastrophe - the steel around the site of rust perforation is usually quite thin. You still need to replace the water tank but this approach can stop or slow a leak while you wait for the new tank to be installed.

If the rust perforation on a steel, bladderless water pressure tank is very tiny, 1/8" or so, temporary repair can sometimes be made using a special short lag-type threaded screw with a neoprene washer. Leak repair screws are sold for this use.

Details of this rusted leaky water tank leak repair procedure are


Where to Locate the Replacement Water Pressure Tank

Water tank in closet (C) Daniel FriedmanLocate the pressure tank as close as practical to the pump pressure control switch. If the water pressure tank located too far from the pressure control switch, or at a different elevation from the pressure switch, the pressure switch control may not operate properly.

Amtrol™ is quite clear about the proper water pressure tank location:

The Well-X-Trol should be installed as close as possible to the pressure switch.

This will reduce the adverse effects of added friction loss and pressure switch bouncing, and the difference in elevation between WELL-X-TROL and switch.

Water pressure tanks will work rather well if placed located almost anywhere on the piping system on the same level as the pressure control switch.

Water Pressure Control Switch Contact Bounce & Short Cycling Water Pumps

But it's best to follow the Amtrol advice - keep the water tank and pressure switch close together. Incorrect water pressure tank location, too far from the pressure control switch for example, can cause improper pressure control operation or pressure control switch contact "bouncing" turning the water pump on and off too rapidly.

Photograph of a steel water tank

If you have a problem such as the pump pressure control switch bouncing (the switch turning the pump on and off rapidly at the start or end of a pumping cycle) you can relocate the pressure switch to the new larger tank and run a longer wire to the pump or pump control relay.

Other causes of pressure switch bounce and well pump short cycling are explained at WATER PUMP SHORT CYCLING CAUSES.

Our photo (above) shows a water tank located correctly in that the pressure control switch (that gray box between the blue water tank and the green treatment tank) is close to the water tank.

The owners located this water pressure tank in a closet and insulated the closet walls with fiberglass.

The result was condensation that soaked the fiberglass, leading to a local mold contamination problem.

Our photo at above left is another illustration of a leaky water pressure tank that is beyond repair.

Water Storage Tank / Cistern Life

Photograph of a rooftop storage tank in ManhattanReader Question: expected life of rainwater harvesting tanks

Unless there are some special effects of the use of a storage tank for harvesting rainwater, I think the tank life will depend on the factors I list below: in short, the tank materials, application, environment, and external influences on it.

I trust the manufacturer to know the minimum life of their product and to reflect that in their warranty, though that's not always the case (see water heater warranties).

If I were concerned for water storage tank life I'd be at least as interested in the factors that affect tank life as I would in the tank material. Sun exposure, exposure to mechanical damage, water chemistry, in some cases water volume use installation details.

Horizontal water storage tank, above ground, Dutchess County NY (C) Daniel FriedmanHere is some scholarly research reporting on water tank life in particular applications:

Water Tank Age Decoder

Pentair water pressure tank label indicating tank date of manufacture or tank age - at  source:

Reader Question: how old is my WellMate water tank?

I have a WellMate pressure tank with the serial number 26106275 Model WM-6

Can you tell me how old this tank is?

Water Tank Age Decoding from Data Tags

Yes Rita

Some water tanks including some Pentair water pressure tanks include a date of manufacture right on the tank's data label as we show in our illustration from Pentair (cited below).

For some other water tank products such as WellMate, the date of manufacture is coded in the serial number as follows:

WellMate Water Tank Age Decoder

For WellMate pressure tanks, the five digits at the beginning of the serial number encode the date of manufacture as follows


Where ddd is the sequential day of the year beginning with 001 and ending at 365, and YY is the 2 digits of year of manufacture.

Your WellMate water tank was made on day 261 of year 2006

Pentair water pressure tank at InspectApedia.comUsing an online calculator ( we find that day 261 of 2006 is 18 September 2006


Continue reading at WATER TANK SAFETY or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see AIR VOLUME CONTROLS, WATER TANK used on bladderless water pressure tanks




For the age of water heaters, calorifiers, geysers, see WATER HEATER AGE & MANUALS

Suggested citation for this web page

WATER TANK REPLACEMENT at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

HTML Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman