Terraces, courtyards and heritage streets. A dead unit is more often a part than a write-off, and where a changeover is needed the real constraint is usually getting the new one to the back of the house.
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Every storage tank is a slow race between the anode and the cylinder. The anode corrodes in place of the steel, and once it is gone the tank is on its own. A tank that has started to go cannot be repaired.
Almost nobody replaces an anode. It is a straightforward job at around five to seven years that adds years to the unit, and it is the single biggest avoidable cost on this page.
What is particular to North Sydney is that there is nowhere to put anything. The terraces have no side passage, rear yards are often courtyards of a few square metres, and the neighbour is close on both sides. Units end up in tight, poorly ventilated spots where they are awkward to inspect and awkward to replace, and the practical result is that they get attention only once they have failed.
One thing it is not: hard water. Sydney's supply is soft, averaging around 43 mg/L, so a failed unit here is almost never limescale.
Tell us the brand, the rough age and where the unit sits. In a terrace the third answer is the one that decides how long the job takes.
Most installation advice assumes a path down the side of the house. A terrace does not have one, so every option gets assessed against getting through the building instead.
A storage cylinder has to come in and out that way, up or down stairs, past finished surfaces.
That is a real part of the job rather than an afterthought, and it belongs in the quote.
Rear yards here are frequently a few square metres with masonry on three sides, which is the worst possible environment for a heat pump.
Not enough air movement for it to work efficiently, and nowhere for the noise to go except into the neighbour's bedroom window.
It is not impossible on this housing, but it is a question to answer honestly before ordering rather than after.
These streets carry conservation areas and many individually significant buildings, and what is fixed to a visible elevation or vented through a street-facing wall is constrained.
That does not make a modern system impossible. It means the position gets decided with the streetscape in mind, and occasionally with approval.
Establishing it early avoids ordering something that cannot be installed where it needs to go.
Older electric tanks here are frequently on a separate off-peak supply that runs for a set window overnight and nothing else.
So the cylinder is carrying the whole day on one cycle, and running out late in the evening is capacity rather than failure.
Many installations have a manual boost that heats outside the window. Finding out whether yours does is worth two minutes before booking anybody.
A magnesium or aluminium rod, sealed in the tank, corroding steadily so the steel does not. It is the only genuine service item a storage unit has.
In a hard-water city the story would be scale. Sydney's supply is soft, so here it is corrosion and the anode is the whole defence.
Nobody thinks to check it because there is nothing to look at, and that is the single biggest reason hot water systems here end short of their potential.
It mounts on a wall, stores nothing, and is small enough to carry through a terrace hallway without difficulty.
On housing where getting a cylinder through the house is the hardest part of the work, that advantage compounds every time the system is replaced.
The trade is a compliant flue position, and with the neighbour's window a metre away that is a genuine calculation rather than a formality.
The compliance plate carries the date. Under about eight years a failure is usually a part. Past twelve the tank lining is generally the issue.
Photograph the plate and send it through before anybody attends. In this part of Sydney parking twice is a real cost.
Between those it depends on the fault, which is why a specific diagnosis matters more than a rule.
A tank that empties mid-shower is generally undersized for how the household now behaves rather than faulty. Capacity is drawn down by what is taken in the same short window.
In a terrace where the existing tank is already the largest that will fit, that pushes the conversation towards continuous flow rather than a bigger cylinder.
Describe your actual mornings when you ask for advice, because that is what the sizing runs on.
A shower draws hot and cold together, so the head sets the rate the cylinder is drawn down at. Older heads can flow well above nine litres a minute.
Where the alternative is a difficult changeover through a narrow house, this is an unusually good thing to try first.
It costs very little, takes minutes, and if it works you have avoided the whole problem.
It is when the water is coming from the cylinder itself rather than from anything bolted to it. That is corrosion having worked all the way through.
The failure mode from there is not gradual. A tank that has begun to seep has lost structure, and when one goes properly the entire contents arrive at once.
So close the water at the unit, kill its supply, and arrange the swap rather than watching it.
Type and size decide most changeovers. In this housing there is a third question that matters as much: whether the thing you want can physically get to where it needs to go.
A larger tank that will not come down a hallway is not an option at any price, which is why continuous flow units are disproportionately common in terraces. They are compact, they mount on a wall, and there is no cylinder to run out.
| System | How it heats | Typical life | Suits |
|---|---|---|---|
| Electric storage | An element heats a tank, often overnight on a controlled load tariff | 8 to 12 years | Where a tank already fits and there is no gas at the property |
| Gas storage | A burner under the tank, reheating through the day | 8 to 12 years | Terraces with gas and enough rear yard for an external unit |
| Continuous flow | Heats on demand, so there is no tank to run out | 15 to 20 years | Tight courtyards and hallway access. Very common in this housing |
| Heat pump | Moves heat from the surrounding air, like a fridge in reverse | 10 to 15 years | Only where the rear yard is genuinely open enough for airflow |
| Solar with boost | Roof collectors with electric or gas backup | 15 to 20 years | Rarely practical on a heritage terrace roof |
A starting point rather than a rule. A household showering back to back within an hour needs more than the same number spread across a morning.
| People in the home | Electric storage | Gas storage | Continuous flow |
|---|---|---|---|
| 1 to 2 | 125 L | 135 L | 16 to 20 L/min |
| 3 to 4 | 160 to 250 L | 135 to 170 L | 20 to 26 L/min |
| 5 or more | 250 to 315 L | 170 L or more | 26 to 32 L/min |
Fixed price agreed before anything starts. Indicative 2026 Sydney ranges. In this housing access can add labour to a changeover and we will tell you that before you commit.
Someone out to you who establishes what has actually failed rather than guessing.
The most common repair on an electric storage tank, and usually the same visit.
Worth doing on a sound tank at five to ten years, especially where access is difficult.
Same type and size. Add time where the unit has to come through the house.
Before the NSW discount and federal certificates, which usually come off up front.
Almost every home here runs one of these eight. In the terraces the field narrows fast: Rinnai and Bosch continuous flow dominate, because a wall-mounted unit fits a courtyard where a cylinder does not.
Where there is room for a tank, Rheem, Vulcan and AquaMAX storage are what we mostly find, often decades old. Dux turns up across storage and heat pump, Solahart on the few roofs that suit it, and Stiebel Eltron on the heat pump installs where the rear yard is generous enough to make one work properly.
Elements, thermostats, anodes and tempering valves for the mainstream brands ride on the van, so a repair is usually same day. The parts that take a day or two are almost always for a unit that stopped being made years ago, which is generally the point at which replacing it is the better spend.
We service and replace these systems as an independent licensed plumber. We are not an agent for, or endorsed by, any manufacturer.
What has failed and how old it is, then how a replacement would physically reach the space. In a terrace the second one shapes the quote.
Repair against changeover, honestly. Where access is hard, extending the life of the unit already in place is often the better spend.
Drop sheets down the hallway, careful handling on old floors, and the old unit out the same way the new one came in.
Temperature checked at the tap, tempering valve verified, courtyard left clean, old unit removed for recycling.
Tell us the brand, the rough age and where the unit sits. If it is in a courtyard behind a terrace, say so, it changes what we bring and how long we book.
Call 1300 381 569What North Sydney locals ask us before booking a plumber.
Ask us yours
If it is electric, check the switchboard for a tripped breaker, and check whether it runs on a controlled-load tariff that only heats overnight. A heavy evening can empty a tank before the next cycle, which looks like a fault and is not one. If it is gas, check the pilot or ignition, and that the gas is on at the meter. Then call and tell us the brand, the rough age and where the unit physically sits, because in a terrace that last answer decides how the job runs.
Honestly, usually not, and the reason is space rather than plumbing. A heat pump needs genuine airflow around it and it makes noise while running. A terrace has no side passage, the rear yard is often a courtyard measured in single-digit square metres, and the neighbour's bedroom window is a few metres away on both sides. Where the rear yard is generous enough it can be done well. Where it is not, saying so is more useful than selling you an appliance you will resent every night.
Most commonly a rear external wall or a tight courtyard, occasionally an internal cupboard in a converted space. What almost never exists is the side passage that most installation guidance quietly assumes. That constrains size as much as type: a 315 litre tank may simply not fit where the old one stood, which is a good reason to consider a continuous flow unit when a changeover comes up.
Through the house, generally. That is normal here and it is why we ask about access before quoting rather than after. It means drop sheets, careful handling down a hallway with a hundred and forty year old floor, and a bit more time at both ends. A quote that has not asked how the unit reaches the back of the property has not thought about your job.
It can affect what is visible. These streets carry conservation areas and a lot of individually significant terraces, and controls generally focus on what can be seen from the public domain. A unit on a rear wall in a courtyard is rarely an issue. A flue or a unit on a street-facing facade may well be. If your property is listed, it is worth checking before ordering rather than after installing.
The anode, most of the time. It is a sacrificial rod inside the tank that corrodes so the steel does not, and when it is consumed the cylinder starts going. Almost nobody replaces one, which is why so many units are scrapped years earlier than they had to be. In this housing there is a second factor: units squeezed into courtyards and cupboards get looked at less often, so problems are found at failure rather than beforehand.
If a heat pump is genuinely viable at your property, yes. The NSW Energy Savings Scheme applies an upfront discount to the installer's quote rather than a rebate later: up to $640 replacing an old electric water heater and up to $330 replacing gas, depending on the model. Only installers partnered with an Accredited Certificate Provider can apply it, so ask any quote whether it is included and who the provider is.
Brand, rough age, and where the unit physically sits. If the only way to it is through the house, that is worth saying up front.
Fixed price agreed before anything starts, and an honest answer on whether a heat pump suits the yard you actually have.
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