Instant vs Storage Water Heaters in Singapore

Finding the right heater: Where to begin?

If you are getting a new home soon or starting to learn about water heaters, you’ve come to the right place. Searching for the right heater is overwhelming. There are so many options in Singapore! I’ll show you an easy too-long-didn’t-read (TLDR) comparison between two instant heaters and two storage heaters. These four make up the most sought after water heaters in Singapore. This comparison is suitable for HDB and condo. For landed homes, go here.

Disclaimer: I work at AOS Bath, and we are water heater specialists. We carry storage heaters and provide some instant heaters, but not gas water heaters. Gas water heaters are only sold by CityGas (government). That said, my priority is to lay out the unbiased facts to help you to make an informed decision. It is not wise to promote a particular heater only to have you realise it is not what you wanted in the first place!

There are no right or wrong answers.

Every water heater caters to different needs. Choose one based on what your family requires. The final decision is yours

TLDR Water Heater Comparison

GAS INSTANT
Energy saving
ELECTRIC INSTANT
Energy saving
ELECTRIC STORAGE
Energy saving
HEAT PUMP STORAGE
Energy saving

That’s was easy! Tell me more.

By looking at the chart, most of you will have a good idea of what water heater you want. Let’s go through a few more facts before making the final decision:

We’ll go deeper into:

  • Price: installation, maintenance
  • Energy saving: what each runs on, carbon footprint
  • Running cost: assumptions and calculations
  • Water pressure: how heaters affect water pressure, rain showers
  • Size: size, location, design

Price

GAS INSTANT
ELECTRIC INSTANT
ELECTRIC STORAGE
HEAT PUMP STORAGE

Gas instant heater: Lowest end is a $180 low flow rate model for HDB. Expect to pay $1300 for a higher end gas water heater heater with a higher flow rate.

Electric instant heater: $150 is the most basic water heater option in Singapore. Note: If you have 2 baths, you need 2 instant heaters as these cannot be shared.

Electric storage heater: $250 is the basic version with only heating light indicator. Expect to fork out at least $700 for more advanced digital water heaters equipped with timers and speed heating.

Heat pump: This renewable energy water heater extracts heat from the air and converts it to hot water. As with all green technology, cost is high but you get your money back fast because it saves at least $600/year.

A gas heater is tankless. A storage heater has a tank. Pictured next to each other for comparison. HDB, Clementi.

Maintenance

Water Heaters are the highest wattage appliances in your home. For your safety, maintain them every 3 years. This prevents gas leaks and wiring issues. Water heaters with poor maintenance fail fast and pose a risk.

Well maintained water heaters can last over 10 years.

Storage heaters need a tank flush every 3 years. This will clear out any sediments so the water you shower with is cleaner.

The water heater is a high wattage appliance. Old electric wires may spark and cause power trips or dangerous short circuits.

Energy Saving

GAS INSTANT
Energy saving
Carbon footprint
ELECTRIC INSTANT
Energy saving
Carbon footprint
ELECTRIC STORAGE
Energy saving
Carbon footprint
HEAT PUMP STORAGE
Energy saving
Carbon footprint

Water heaters account for about 20% of the total electricity consumption in a home.

Gas instant heater: Gas is a cleaner source of energy compared to electricity.

Electric instant heater: Electric consumption is low due to low flow rate.

Electric storage heater: Highest energy consumer of the 4 heaters.

Heat pump: Lowest energy consumer, renewable energy. Uses free air heat to heat water.

Carbon footprint

Gas has a lower carbon footprint compared to electricity. In Singapore, we get by burning gas at a power station. Gas powered heaters skip this stage and have a lower carbon footprint.

Heat pumps have an even lower carbon footprint as they use very little electricity to heat water. Find out how they save money here.

Run cost / person

GAS INSTANT
ELECTRIC INSTANT
ELECTRIC STORAGE
HEAT PUMP STORAGE
Assumptions

Electric storage heater: An NUS study estimates a Singaporean takes 20 min x 2 showers a day. For HDB and condos, we reduced this to around 10 min per shower to get $10/month.

Electric instant heater: heaters are also 3000 watts, but their water pressure is lower. From $10/month, we reduce -40% to get $6/month.

Gas instant heaters cost about the same to run as Electric Storage. They are greener because gas appliances skip the power station. For lower flow rate HDB models, reduce -20% to get $8/month. High flow rate condo models run at $10/month.

Heat pump water heaters need electricity to run a fan that draws in free air heat. Reduce -75% to get about $3/month.

Calculations

We used this Energy Calculator.

Water Pressure

GAS INSTANT
ELECTRIC INSTANT
ELECTRIC STORAGE
HEAT PUMP STORAGE

Instant heaters are pressure reducing.

They slow down water flow rate, giving it time to heat up as it flows through the system.

Storage heaters are pressure maximising.

If cold water goes into the tank at 15 lit/min, the hot water output is 15 lit/min. Water pressure can go up to 25 lit/min.

Why is high water pressure so important today?

In the past, high-flow rain showers and body jets did not exist. Today, they are trending. Our standards are getting higher. To support rain showers, a heater should produce 10 lit/min.

HDB gas water heaters are around 8 lit/min. When paired with rain showers, water pressure is low.

Size

GAS INSTANT
ELECTRIC INSTANT
ELECTRIC STORAGE
HEAT PUMP STORAGE
Size, location and design

Gas instant heater: Installed at service yard or aircon ledge for safety. Small, leaves enough space for clothes rack or washing machine.

Electric instant heater: Installed at shower area. Compact and won’t take up too much space. For BTOs with concealed piping, there will be an extra exposed pipe to the shower area.

Electric storage heater: Bigger than instant heaters as it comes with a tank. Can install in common bathroom (up to 50 lit) or above false ceiling.

Heat pump heater: Biggest tank in this range because it is a tank + compressor. For HDB, heat pumps are often shifted to the yard. In condos, they can fit above false ceilings.

  1. Electric storage heater, BTO
  2. Gas heater, condo
  3. Heat pump, BTO yard
How fast will you get hot water?

The closer the heater is to your shower point, the faster you will get hot water.

This is different from the heating time of a water heater. For more on that, check out this article.

Conclusion: Instant or Storage?

It’s all about personal preference, there are no right or wrong answers. Pick a heater that suits your lifestyle!

Unsure? Take a heater quiz for some answers.

Heaters that weren’t covered:

Digital water heaters

Digital heaters fall under the category of ‘Electric storage water Heaters’. As they are more advanced, they command higher prices. Digital heaters have speed heating, hot water multiplier technology and built in timers.

Multipoint heaters fall under the category of ‘Electric instant Water Heaters’. They have a higher water pressure of 8-12 lit/min and consume more energy.

Regular instant heaters run at 3000 watts, while a multipoint heater uses 4000 watts. If you are installing one, ensure your heater track is 20 Amp instead of 15 Amp. Older houses usually have water heater tracks with lower power rating.

Read: Multipoint heater review

Solar heaters, like heat pumps are renewable energy heaters. They are a type of storage water heater. Instead of running on heat from the air, they run on heat from the sun.

These are instant water heaters with slightly higher flow rate, 5 lit/min. Comes with a small booster pump (legal). Demo pump noise level before purchasing.

Other related articles:

How long do storage heaters take to heat?

Did you know that if you use your storage heater daily, you may not have to wait for hot water at all!

Gas vs. electric heaters

Gas heaters are also pressure reducing systems. If showers in both bathrooms are running at the same time, users will feel a flow rate drop.

5 ways digital heaters saves you time and money

From our range, the most popular water heaters for HDB are digital heaters while heat pumps take top spot for private housing. Find out why.

Amanda

Amanda

Amanda is an education specialist at AOS Bath. She enjoys building a trusted network by sharing knowledge. Making difficult concepts simple and engaging is rewarding, on both ends.