A hot water tank that is swelling, bulging or leaking is not something to ignore. Visible changes to the shape of a storage hot water system, particularly when combined with water leaking from the unit, can indicate that the system is deteriorating and needs to be inspected.
We recently attended a property where the existing hot water unit was showing exactly these signs. The outer casing had visibly swollen and separated along the side, while water was leaking from the lower section of the system.
The homeowner had already used our Hot Water Selector to explore their replacement options. After inspecting the existing installation, we recommended a new stainless steel hot water system, provided the price and received approval to proceed.
We returned the following day to complete the replacement.
Why Is My Hot Water Tank Swelling?
A hot water storage tank should not normally begin bulging, swelling or changing shape. If the outer casing starts distorting, it can be a sign that something within the ageing system has deteriorated.
The visible casing on a storage hot water system surrounds the internal tank, insulation and other components. As a system ages, corrosion, water ingress or deterioration inside the unit can result in visible changes to the exterior.
Swelling does not tell you exactly which internal component has failed, which is why the system should be inspected rather than diagnosed from appearance alone. However, a hot water unit that is visibly changing shape deserves attention.
Why Is My Hot Water System Leaking?
A leaking hot water system can have several possible causes. Some leaks can come from valves, fittings or pipework, while others may indicate deterioration of the storage tank itself.
Signs worth watching for include:
- Water collecting around the base of the hot water unit
- Water running down the outside of the tank
- Rust or corrosion around the casing or fittings
- Bulging or swelling of the outer casing
- Sections of the casing beginning to separate
- A leak that continues or becomes progressively worse
If a hot water unit is both swelling and leaking, it is particularly important to have the system checked. Repairing a fitting will not solve the problem if the tank itself has reached the end of its serviceable life.
Can a Leaking Hot Water Tank Get Worse?
Yes. A small hot water leak can become a much larger problem if the underlying cause continues to deteriorate.
This is why it is generally better to investigate an ageing or leaking storage system while you still have hot water rather than waiting until the unit fails completely.
A planned replacement also gives you time to compare different hot water technologies, capacities and tank materials rather than making a rushed decision because the household suddenly has no hot water.
When Should a Swelling Hot Water System Be Replaced?
Whether a hot water system needs repair or replacement depends on what is actually causing the problem, the age and condition of the unit and whether the storage tank itself has deteriorated.
In this case, the combination of visible swelling, leaking and the overall condition of the old unit made replacement the sensible option.
The homeowner had already started researching their options through our Hot Water Selector, which made it easier to discuss the replacement system once we inspected the property.
Why We Recommended a Stainless Steel Hot Water System
After looking at the existing installation and the customer’s requirements, we recommended a stainless steel storage hot water system.
Stainless steel tanks are highly resistant to corrosion and do not use the same vitreous enamel tank lining and sacrificial anode arrangement found in many traditional steel storage systems.
For suitable properties, a stainless steel unit can provide several advantages:
- Strong resistance to internal corrosion
- No sacrificial anode inside the stainless steel tank
- Reduced tank maintenance requirements
- Lightweight construction compared with many traditional storage tanks
- A strong long-term replacement option when correctly matched to the property
That does not mean stainless steel is automatically the right hot water system for every home. Household size, water usage, available energy source, installation conditions and budget should all be considered before selecting a replacement.
Using the Hot Water Selector Before We Arrive
This job was also a good example of how our Hot Water Selector is designed to work.
The homeowner used the selector before contacting us, giving them an opportunity to understand the available hot water options before we inspected the existing system.
We could then assess the property, confirm what would work with the existing installation and recommend an appropriate replacement.
The customer was happy with the recommendation and price, and we returned the following day to complete the replacement.
What Should You Do If Your Hot Water Tank Is Swelling or Leaking?
If you notice your hot water unit swelling, bulging, separating or leaking, arrange to have it inspected rather than waiting for the problem to become worse.
Pay particular attention to:
- Bulging sides or panels
- Changes to the shape of the tank
- Water around the bottom of the system
- Rust stains or corrosion
- Persistent dripping or leaking
- A noticeable deterioration in the condition of an older unit
If replacement is required, you can also use the RJT Plumbing & Gas Hot Water Selector to explore suitable options before we arrive.
Do Not Wait for a Leaking Hot Water System to Completely Fail
A hot water tank that is visibly swelling and leaking is already giving you a warning.
Getting the system inspected while it is still operating gives you more control over what happens next. You can understand why the existing unit is failing, compare replacement options and organise the work before you are left unexpectedly without hot water.
If your hot water unit is swelling, bulging, rusting or leaking, contact RJT Plumbing & Gas or use our Hot Water Selector to start comparing replacement options.
Frequently Asked Questions
Why is my hot water tank swelling?
A hot water storage system should not normally begin swelling, bulging or changing shape. Visible distortion can indicate deterioration within the ageing system, including corrosion, water ingress or damage inside the unit. The system should be inspected to determine the actual cause.
Why is my hot water system leaking?
A hot water system can leak from valves, fittings, pipework or the storage tank itself. Water around the base of the unit, corrosion, persistent leaking or visible distortion of the tank are signs that the system should be inspected.
Is a swelling hot water tank normal?
No. A hot water tank or its outer casing should not normally bulge, swell or noticeably change shape. Visible swelling should be investigated, particularly when the system is also leaking or showing signs of corrosion.
Can a leaking hot water tank get worse?
Yes. A small leak can become more significant if the underlying component or storage tank continues to deteriorate. Having the system inspected early can allow repair or replacement to be planned before a complete failure occurs.
Should I replace a hot water system that is swelling and leaking?
Whether replacement is required depends on the cause, age and overall condition of the system. When an older storage hot water unit is both visibly swelling and leaking, replacement may be more appropriate than continuing to repair an extensively deteriorated system.
What are the signs that a hot water system may be failing?
Possible warning signs include water around the base of the unit, persistent leaking, rust or corrosion, bulging or swelling of the casing, sections of the casing separating and a noticeable deterioration in the condition or performance of the system.
Why choose a stainless steel hot water system?
Stainless steel hot water tanks offer strong corrosion resistance and do not use the same vitreous enamel tank lining and sacrificial anode arrangement found in many traditional steel storage systems. Suitability still depends on the property, household requirements and installation conditions.
How can I choose a replacement hot water system?
The right replacement depends on household size, hot water demand, energy source, available space, existing infrastructure and budget. RJT Plumbing & Gas provides a Hot Water Selector that can help homeowners explore suitable options before an on-site assessment.
