Old gas heater:
New gas heater:
The inspection confirmed the heater was beyond economical repair:
We then carried out a CO leak test. The reading exceeded the widely referenced 50 PPM occupational exposure threshold — a clear fail.
Carbon monoxide is called the silent killer for a reason: it is invisible, odourless and tasteless. You cannot see it, smell it or taste it — you only feel its effects, and by then exposure has already happened.
With a confirmed CO leak from an obstructed burner, the safe reading is the one you never take a chance on. We closed the gas valve on the spot and instructed the household not to use the heater until it was replaced. The replacement was scheduled for the very next day.
The homeowner chose to stay with the same model family — the Macro MA-20WODP, a gas water heater with a preheat function, powered by piped town gas from Citygas (now City Energy). Keeping the same model meant the household got back the exact hot water experience they were used to, on a brand-new, safe unit.
A standard gas water heater only starts heating when you open a hot water tap — so the water already sitting in the pipes between the heater and your shower comes out cold first. The longer the pipe run, the longer you wait.
The preheat function solves this with a heating loop return: the heater circulates hot water through the piping in advance, so hot water is already waiting at the outlet the moment you turn on the tap. In practice, this cuts hot water delivery time from around 1 minute to about 5 seconds.
The preheat function delivers the most benefit in homes with long piping runs — double-storey homes, landed properties and penthouses — where the wait for hot water is longest. For this SkyPark Residences household, it was the comfort feature they already knew and did not want to give up: hot water at every outlet within seconds, every morning.
Before starting work, we walked the customer through exactly what a proper gas water heater replacement involves. A safe installation is never just “swap the box on the wall”. Our scope covered:
The Certificate of Gas Safety is the document that confirms the gas installation has been tested and certified safe by a licensed gas service worker — we have covered what it is and why it matters in detail elsewhere on our website.
Once installation was complete, we ran a temperature test to confirm the heater was delivering hot water correctly and functioning as intended. We finished with full housekeeping of the work area — the customer’s home was left the way we found it, minus one dangerous heater.
Total time on site: approximately 3.5 to 4 hours.
If your gas water heater is approaching 10 years of age, do not wait for it to fail — and never ignore inconsistent performance. An ageing heater is not just an inconvenience; as this SkyPark Residences case shows, a corroded burner can leak carbon monoxide into your home without any visible warning.
Homeone provides site assessments, CO leak testing, and licensed gas water heater replacement across Sembawang and island-wide, with a Certificate of Gas Safety issued on every gas installation.
