This Comes Up in Almost Every Bathroom Renovation
Replace the water heater with a gas instant heater or stick with a storage electric heater? For a question that comes down to a few thousand dollars and a long-term daily experience, it gets surprisingly little careful thought in most renovation planning conversations. Here is the honest breakdown so you can make the right call for your household.
How Each System Works
A storage water heater heats a tank of water and keeps it hot. When you turn on the shower, you are drawing from that pre-heated tank. The tank in Singapore HDB flats typically holds 15 to 25 litres. Once that volume is used, you wait for the tank to reheat before hot water is available again.
A gas instant heater heats water on demand as it flows through the unit. There is no tank and no waiting. As long as gas is supplied and the unit is functioning, hot water is continuous and immediate. There is no limit on duration.
The Case for a Gas Instant Heater
For households with more than two people sharing a single bathroom, a gas instant heater is a significantly better experience. No cold showers because someone else used the tank first. No waiting fifteen minutes between showers. Continuous hot water for as long as you need it.
Gas heaters are also more energy-efficient in the sense that they do not keep a tank of water hot around the clock. You use energy only when you are actually using hot water. Over time, this can result in lower utility bills compared to a storage heater that cycles on and off all day maintaining tank temperature.
The trade-off is the installation. A gas instant heater requires a gas point in the bathroom, which means gas piping must reach the unit. In some HDB flats this is straightforward. In others, particularly where the bathroom is far from the main gas riser, routing new gas piping is more involved and requires a licensed gas contractor and the relevant permits. This adds to the upfront cost.
The Case for a Storage Electric Heater
For a single-person household or a couple with staggered shower schedules, a modern storage heater is entirely adequate and simpler to install. If there is already an electrical point near the heater position, replacement is straightforward and does not require any gas works.
Storage heaters are also the lower-risk option in terms of maintenance. Gas appliances require periodic servicing and the gas piping and connection must be maintained by licensed personnel. An electric storage heater has fewer moving parts and less that can go wrong.
Modern storage heaters have improved significantly in terms of insulation and heat retention. A quality unit from a reputable brand loses less heat overnight than older models and recovers faster after use.
The Practical Decision Framework
Choose a gas instant heater if:
- Your household has three or more people sharing one or two bathrooms
- Morning shower schedules overlap frequently
- There is already gas piping accessible near the bathroom location
- You are doing a full bathroom renovation anyway and can plan the gas point as part of the scope
Choose a storage electric heater if:
- You live alone or with one other person
- There is no gas supply accessible near the bathroom and routing new piping is expensive
- Budget is a constraint and you want to minimise installation complexity
- The existing heater position has an electrical point and you simply need to replace the unit
Installation Requirements
For gas heaters: all gas piping and connection work must be done by a licensed gas contractor. The heater must be installed with adequate ventilation as specified by the manufacturer. Gas work requires a permit and inspection.
For storage electric heaters: the unit must be on a dedicated electrical circuit with the appropriate rating. This is part of the scope our electrical contractors handle as part of bathroom renovations.
Both types of heater replacement are typically included in our bathroom renovation scope. Our full HDB bathroom renovation guide covers heater selection alongside tiles, fittings and waterproofing decisions. Contact us if you want a recommendation based on your specific flat layout and household.
