Water heater FAQ: choosing a heater
These answers help you narrow down a new heater before you ask for quotes.
Which costs less to run, instant or storage?
Compare running costs model by model before you decide. Our instant or storage running cost comparison explains how the two types differ to run. In the shop, check each model's label: the National Environment Agency (NEA) Energy Label covers water heaters and rates efficiency in ticks, from 1 (Low) to 5 (Excellent).
Gas or electric: how do I choose?
Compare the two types side by side before you buy. Our gas or electric water heater comparison sets out the differences. Each model's Energy Label states its type (electric instantaneous, gas instantaneous, electric storage or heat pump) and its rated input power in kW for electric models, or nominal heat input in kW for gas.
What size of storage heater do I need?
Use our water heater size calculator to estimate the capacity your household needs before you shop. The Energy Label on a storage heater shows its capacity in litres, so you can compare models against your estimate. Ask the installer to confirm that the heater you choose fits the space and suits your home.
Safety and tripping
These answers cover how a heater should be powered and when to stop using one.
Can a water heater run off a 3-pin plug?
No. The Consumer Product Safety Office (CPSO) says to wire a water heater directly to the mains through a double pole switch, not to a 3-pin socket outlet. In a 2018 written answer to Parliament, the Ministry of National Development (MND) said heaters should use a 20 ampere socket switch, not a normal 13 ampere 3-pin socket. Our water heater 3-pin plug safety guide explains more.
Why does my water heater trip the power?
A trip is the circuit protection cutting the power, and the cause needs finding. Our water heater tripping guide explains the usual causes. Leave the heater off and call a Licensed Electrician to find the fault. If water is anywhere near the heater, its switch or the distribution board (DB box), read the safety note below first.
What are the warning signs of an unsafe heater?
A heater that looks damaged or is leaking is one: the CPSO says not to use it. The CPSO also says to make sure a storage water heater has a pressure relief valve, so ask your installer if you cannot see one. Our water heater warning signs post covers more signs to look out for.
Installation and replacement
A new or replacement heater involves two kinds of licensed work, the wiring and the pipework. Here is who does what, and how to compare quotes.
Who may install a water heater?
Wiring is work for a Licensed Electrical Worker (LEW): EMA says electrical work at home should be carried out or supervised by one. EMA says electrical work in an HDB flat needs a Licensed Electrician, the class of LEW approved for loads of up to 45kVA.
PUB lets a handyman replace only the pipe between a stop valve and an instantaneous water heater; other pipework is work for a PUB Licensed Plumber. See our water heater installation steps.
What does a replacement cost?
It depends on the job. Our water heater replacement cost guide explains what goes into the price. When you compare quotes, ask each company what is included, such as the new heater, the wiring and pipe connections, and removal of the old unit, so that every quote covers the same work.
What should I do if the heater leaks?
Stop using it. The CPSO says not to use a water heater that is leaking. Keep away from any switch, socket or wiring the water has reached and call a Licensed Electrician; call 995 if there is fire, smoke or someone is hurt. Our water heater leaking guide covers what to do next.
NEXT STEP
See plumbing companies in the directory with their published prices, the areas they say they cover and their sources.
Compare plumbersWhere to go next
The answers above are kept short on purpose. When you need more, these pages take the next step, whether you are working out why the shower has gone cold, planning an installation or looking for a company to do the job.
- No hot water: a guide for when the shower runs cold.
- Water heater installation: companies listed for heater installation work.
- Instant water heaters: companies listed for instantaneous heater work.
- Plumbing costs: how plumbing jobs are priced.
- Plumbing companies: plumbing companies in the directory and the areas they say they cover.
Questions
Should I switch the water heater off after showering?
Yes. The Consumer Product Safety Office (CPSO) advises switching a water heater off when it is not in use. Wait until you are dry and the floor near the switch is dry before you touch it. Never reach for the switch with wet hands or while standing on a wet floor.
Does a water heater need regular servicing?
Yes. The Consumer Product Safety Office (CPSO) advises engaging a professional to service your water heater regularly. When you book, ask the company what the service covers. Do not open the heater's cover or touch its wiring yourself, and stop using the heater if it looks damaged or starts to leak.
Can I repair a water heater myself?
No. The Consumer Product Safety Office (CPSO) says not to modify or repair a water heater yourself; engage a professional to check and fix it. If the heater looks damaged or is leaking, stop using it until it has been checked, and keep away from any electrics that water has reached.
Must a water heater carry the SAFETY Mark?
Yes. The Consumer Product Safety Office (CPSO) lists instantaneous and storage electric water heaters as Controlled Goods, which must carry the SAFETY Mark before they can be sold in Singapore. Look for the mark before you buy. Our SAFETY Mark explained post has more on the mark.
Can I power a water heater with an extension cord?
No. The Consumer Product Safety Office (CPSO) says not to use extension cords or multi-way outlets to power a water heater. It should be wired directly to the mains through a double pole switch, and the CPSO advises hiring a Licensed Electrical Worker to make sure the heater is properly wired.
Do water heaters carry the Energy Label?
Yes. The National Environment Agency (NEA) Energy Label covers water heaters and rates their efficiency in ticks. The label shows the heater type, such as electric storage or gas instantaneous, and its rated input power in kW for electric models or nominal heat input for gas. Storage models also show their capacity in litres.
Practical guidance for planning a home job in Singapore. Company prices come from the HomezyPro directory, each linked to its source; rules and safety points link to the agency or manufacturer that sets them. This is not a site inspection, a quote or professional advice for your home.
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