Updated 16 Oct 2026Instant vs storage8 min read
Instant or storage water heater: which should I get?
Quick answer
Get an instant heater if each bathroom is used by one person at a time with an ordinary shower head; get a storage heater if two bathrooms run together, you want a strong rain shower, or you have a bathtub. Instant heaters are cheaper to buy and install, while a storage heater must be installed by a PUB Licensed Plumber.
Side by side
| Instant | Storage | |
|---|---|---|
| Unit price, Oct 2026 | Around $100–400; basic models $108–150 | Around $239–549 for 15–35L; 50L and up more |
| Installation labour | $120–280 from a plumber; some retailers $70–90 with the unit | $150–250 like-for-like; $250–750 for a new position |
| Who may install it | No PUB licence needed for the plumbing | Must be a PUB Licensed Plumber, to SS 636 |
| Electrical | A double pole switch near the shower, wired by an LEW | A heater point wired by an LEW |
| Hot water at several points at once | No. One unit, one outlet | Yes, until the tank runs out |
| Rain shower | Only pump or rain-shower models, and gentler | Handles it well if the tank is big enough |
| Wait for hot water | Seconds | Ariston figures: 20–50 min to heat a full tank, depending on size and element |
| Space | About 30 x 23 x 10 cm on the shower wall (Ariston Aures Easy) | A tank on the wall or above the false ceiling |
| Bathtub | No | Yes, at around 50L |
| Warranty pattern | Often 1–2 yr; some give 5 yr on the element | Often 5 yr tank, 1 yr element |
The licence row is the one most comparison pages leave out. It changes both the price of the job and who you can hire.
Which one for your home
| Household | Better fit | Notes |
|---|---|---|
| 3-room HDB, couple, one bathroom | Instant | A basic 3.3 kW unit at around $108–150 covers it. If you shower at the same time, a 15L tank is the alternative. |
| 4-room HDB, family of four, two bathrooms | Either | Two instant heaters, one per bathroom, or one 30–35L tank feeding both. The tank also gives the kitchen sink hot water. |
| 5-room or executive, family with teens, two bathrooms in the evening rush | Storage | Back-to-back showers empty a small tank. Choose 35L or more with a fast element, or a tank plus an instant heater in the second bathroom. |
| Any home with a bathtub | Storage | Around 50L. No electric instant heater fills a tub. |
| Wants a large rain shower head | Storage | Or an instant pump model, accepting a gentler flow. |
| Landed, three or more bathrooms | Mix | Long pipe runs mean waiting at far taps, so a heater near each bathroom is worth pricing. |
You can also mix: a tank for the main bathroom, and an instant heater in the bathroom fewer people use.
Running cost: what the evidence actually shows
Every ranking page says instant heaters are cheaper to run because they heat only while the water flows, and storage tanks keep reheating stored water. That logic holds. What none of them give is a number you can check. AOS Bath quotes a $0.33 a day gap but states no tariff or usage, and then calls the difference a fraction of a cent in its own conclusion.
The firmer figures come from NEA. Water heaters make up about 10% of a typical household's energy use. Since 1 April 2025, storage, instant and heat pump water heaters sold here must carry an energy label from 1 to 5 ticks, and NEA says moving from a 1-tick to a 5-tick heater saves up to $115 a year at $0.27/kWh.
So the label is a better guide than the type. On the Courts pages we checked, the Champs Virgo Ace and KDK TG3BL1 instant heaters showed 4 ticks, and the 707 Dalton 25 storage heater showed 1 tick. Compare ticks across the models you are choosing between.
Cut storage heater waste
Switch a storage heater off when nobody will need hot water for a while. CPSO also advises switching heaters off when not in use, for safety.
Rain showers, pressure and the flow limit
An instant heater can only heat so much water as it passes through. Ariston's Aures instant heaters are rated for 2 to 7 litres a minute. A wide rain head spreads that flow out, so it feels weaker and cooler than the same head on a storage tank.
Pump models help when the problem is low pressure. Ariston's basic Aures Easy needs at least 0.2 bar to work; its Pump & Rainshower version needs 0.1 bar. A pump does not raise the heating limit, though. If two people in the house want a strong rain shower, choose storage.
Heat-up time is the storage side of the same trade-off, and it depends on the element more than the tank. Ariston lists 28 minutes for its 35L Pro RS J with an element of up to 3.3 kW, and 48 minutes for its 30L Andris 3 RS with a 1.5 kW element. KDK's blog says storage heaters take around 15 minutes and Rheem's blog says up to an hour. The spec sheet for the exact model is the only figure worth using.
What about gas?
Gas water heaters are an option only if your home already has a piped gas supply. EMA requires every piped gas appliance to be installed by a licensed gas worker, who gives you a written statement that it has been tested and is safe. You can search for licensed gas workers on EMA's ELISE portal.
We do not have checked Singapore prices for gas heaters or their installation, so this guide does not compare their cost. If you are deciding between gas and electric storage, ask the gas supplier or a licensed gas worker for a written quote and compare it with the electric figures above.
Switching from one type to the other
Most of the cost of switching is in the pipes and wiring, not the heater.
| Change | What has to happen | Who | Typical cost |
|---|---|---|---|
| Instant to storage | Mount the tank, run hot water pipes from it to each outlet, add a relief valve with a drain to the floor trap, wire a heater point | PUB Licensed Plumber for the heater and pipes; LEW for wiring | Labour $250–750 with new piping; tank $150–450 for 15–50L; power point $250–450 if needed |
| Storage to instant | Remove the tank, cap or reroute the hot pipes, fit a heater at each shower, add a power point beside each one | A plumber for the plumbing (no PUB licence needed for instant); LEW for each new point | Labour $120–280 per heater; unit $110–380 each; power point $250–450 each; old tank removal $30–80 |
| Storage to storage, same spot | Swap the tank, reuse pipes and power point | PUB Licensed Plumber | Labour $150–250; unit extra |
| Instant to instant, same spot | Swap the unit | Any plumber | Labour $120–280, or $70–90 at some retailers |
Losing hot water at the kitchen sink
A storage tank can feed the kitchen sink as well as the showers. Switching to instant heaters at each shower ends that, unless you add another heater for the kitchen.
Lifespan and warranty
Lifespan figures for the two types are not reliable. Home & Decor puts instant heaters at five to seven years and storage heaters at ten or more. SparkFlow's comparison has a lifespan row and leaves it blank. None of the manufacturer pages we checked gives a lifespan at all.
The warranty is something a brand puts in writing, so compare that instead. Ariston gives 5 years on the tank and 1 year on the element for its storage heaters, and 5 years on the element and 1 year on parts for its Aures instant heaters. Champs and KDK instant heaters carried 2 years at Courts; Panasonic and Toshiba, 1 year. See the brands compared for more.
Getting it installed
We install and replace both types island-wide, 24/7. Storage heater work is done by a PUB Licensed Plumber, and electrical work goes to a Licensed Electrical Worker. Send a photo of your bathroom and current heater on WhatsApp for a price range; the final price is agreed before work starts. Workmanship carries a warranty of 1 week to 1 month depending on the job, and the heater carries the manufacturer's warranty.
See instant water heater installation, storage water heater installation, storage heaters in HDB flats and storage heater prices. Model picks: best instant water heater, best storage water heater and the water heater buying guide.
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Frequently asked questions
Which is better, an instant heater or a storage heater?
Neither is better for every home. Instant suits one person at a time in each bathroom with a normal shower head. Storage suits two bathrooms in use together, rain showers, a bathtub, or hot water at the kitchen sink.
What are the disadvantages of instant water heaters?
One unit serves one outlet, so every bathroom needs its own heater and power point. The flow it can heat is limited (Ariston's Aures range is rated 2 to 7 litres a minute), so rain showers feel gentler and two showers cannot share one unit. Low water pressure can stop a basic model from switching on.
Is an instant water heater better?
It is cheaper to buy, simpler to install and has no wait for hot water. It is not better for families who shower back to back in two bathrooms, or for anyone who wants a bathtub or a strong rain shower.
Which type of water heater is better in Singapore, gas or storage?
Gas is only an option if your home already has a piped gas supply, and it must be installed by an EMA-licensed gas worker. Most homes compare electric instant and electric storage. We have no checked price or efficiency data for gas heaters, so get a written quote before deciding.
Do I need a licensed plumber for an instant heater?
No. PUB does not require a Licensed Plumber to install an instant heater, and the pipe between the stop valve and the heater is exempt too. A storage heater does need a PUB Licensed Plumber. Any new power point needs a Licensed Electrical Worker.
Can one instant heater serve two bathrooms?
No. Instant heaters sold for Singapore homes serve one outlet. Two bathrooms need two heaters, or one storage tank feeding both.
How much does it cost to switch from storage to instant?
For each bathroom, budget about $120–280 labour and $110–380 for the unit, plus $250–450 for a new power point if there is none by the shower. Removing the old tank adds about $30–80.