A gas storage tank is the workhorse of a lot of Gold Coast homes: a burner under a tank, fast recovery, and hot water for a full house without the wall-mounted continuous flow price. Here is what a replacement costs and what moves the number.
Gas storage hot water installed: the price
| Job | Price | What it covers |
|---|---|---|
| Gas storage replacement, like-for-like | $1,800 to $3,200 supply + install | New tank, same fuel and position, old unit removed, valves checked or replaced, commissioned, gas compliance certificate and Form 4 |
| Repair to an existing gas storage unit | Quoted after diagnosis | Thermocouple, gas valve, pilot assembly or plumbing valve faults. No published figure |
| Gas continuous flow, for comparison | $1,900 to $3,500 supply + install | No tank, endless hot water, sized by flow rate |
| Electric storage, for comparison | $1,300 to $2,400 supply + install | Cheapest to buy, dearest to run on full tariff |
| Heat pump, for comparison | $2,500 to $4,500 supply + install after STC rebates | Dearest to buy, cheapest to run |
What decides the price inside the range?
Two things, and they are both easy to see standing in front of the old unit. The first is tank size. Gas storage tanks come in a few common sizes, and the 135 litre, 170 litre and 250 litre classes are the ones we fit most. A bigger tank costs more to buy and takes more effort to move, so a 250 litre changeover sits higher than a 135. The second is the flue and cabinet. An external gas storage tank standing in the open with its own weatherproof top needs no flue, and that is the simplest install. A tank inside a cabinet, a garage or a laundry has a flue running to the outside, and if the new unit matches the old one the existing flue and cabinet can often be reused. If the new tank is a different height or diameter, or the old flue is corroded, undersized or not to the current standard, the flue gets replaced or rerouted and the cabinet may need work, and that is the part that pushes a job to the top of the range. We check both at the quote, so the number you get is the number you pay.
What the $1,800 to $3,200 buys you
The tank from a mainstream brand with the warranty registered to you, delivery and removal of the old unit, connection to the existing gas, cold and hot pipework, a tempering valve, relief valve and pressure limiting valve where required, lighting and commissioning, a check of the delivery temperature at the taps, the gas compliance certificate, and the Form 4 to the QBCC. In Queensland a like-for-like hot water replacement is notifiable plumbing work, so the licensed plumber lodges a Form 4 with the QBCC after the job. Because it is a gas appliance, the gas side of the work must be done by a licensed gas fitter, and you must receive a gas compliance certificate for it. Those are two separate licences under two separate pieces of Queensland law. Our QBCC plumbing licence, 15243081, covers the plumbing. The gas work is done under a separate Queensland gas work licence, and the compliance certificate is included in the job, not sold as an extra. A quote that leaves the certificate out is either missing it or planning to skip it, and neither is a saving.
Which tank size should I choose?
Gas storage recovers fast, so the tank does not need to hold a whole day's water the way an off-peak electric tank does. A 135 litre tank keeps a couple or a small family in hot water with the burner catching up between showers. A 170 litre tank is the common pick for a three or four person home. A 250 litre tank suits a big household, a home with two bathrooms in use at the same time, or anyone who has been running out. If your old tank never ran out, the same size again is fine. If it ran out on busy mornings, go up a size now rather than living with it for another decade, because the difference in price at changeover is far smaller than replacing a tank that is too small.
Should I switch to continuous flow instead?
Ask us, because the answer depends on your house, not on ours. Continuous flow at $1,900 to $3,500 supply and install gives you endless hot water and removes the tank's standing loss, and it is what most gas households changing over today end up with. Storage still wins when you want the cheapest possible gas changeover, when the existing tank position, flue and gas line all suit another tank, or when two bathrooms draw hard at the same time and you would rather have a full tank backing the burner. The catch with a switch is the gas line: a continuous flow unit draws more gas when it fires than a storage burner does, and the existing supply pipe is sometimes too small for it. That is inspected and quoted on the day, with no guessing. We cover this in more detail on our continuous flow cost page.
What about an electric or heat pump unit instead of gas?
If the house already has gas, staying on gas is usually the simplest and the recommendation we make most often. If you are open to changing, a heat pump at $2,500 to $4,500 after STC rebates is the cheapest of the four to run in the Gold Coast climate, and STCs and any state rebate can take $1,000 to $2,500 off the sticker. It needs an electrical circuit and a spot with airflow rather than a gas line and a flue, so it is a different install, not a drop-in swap. We will lay out both honestly at the quote.
Is it worth repairing the old gas storage tank?
If the tank is not leaking, a pilot that will not stay lit, a failed thermocouple or a tired gas valve are all repairable, and the price is quoted after diagnosis because the part decides it. Before you ring, check the pilot light and relight it once by the sticker instructions, check the gas isolation valve is fully open, and check other gas appliances in the house are working. A tank weeping from the cylinder is not repairable, and that is when the money goes on a replacement.
Gas storage tank leaking or out of hot water? Call Hills Plumbing & Gas on 0472 657 042 or book through our Hot Water Systems service page. Fixed price, licensed gas fitting with the compliance certificate included, and honest advice on whether storage or continuous flow is the better fit for your place. Jieye.