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By Jason Lim, REN 84424 · IQI Realty · Checked on 15 November 2026
This guide is for owners, buyers and tenants of terrace houses, semi-Ds and bungalows in Johor Bahru, including buyers from Singapore, Indonesia, India and China. The short answer: most landed homes store water in a tank (tangki air) in the roof space that feeds the showers, toilets and most taps. No Malaysian law sets how often a private house tank must be cleaned, but plumbers suggest about once a year, plus extra cleaning after muddy water or if anything gets in. Because the job means ladders, hot roof spaces and a heavy tank of water, most owners hire a plumber; in condos the tanks are the management’s job.
Quick answer
- Why you have a tank: the 2014 plumbing rules put a storage tank between the meter and every tap except the kitchen drinking tap.
- How often: no legal schedule for private houses; the Master Plumbers Association suggested yearly cleaning (The Star, November 2024).
- Clean sooner: after muddy water, pipe repairs or a long empty period, or if anything gets inside.
- Safety: roof spaces are hot and ceiling boards will not hold your weight. DOSH treats storage tanks as confined spaces for workers.
- Who does it: usually a plumber; Ranhill SAJ lists registered plumbers on its website. In condos the JMB or MC looks after the tanks.
- The cover matters: a loose lid lets in dirt and mosquitoes, and Aedes breeding on your premises can lead to a fine under Act 154.
Where your tank is and what the rules say
In Johor, Ranhill SAJ supplies treated water up to your meter. After the meter, the pipes, tank, float valve and taps are the owner’s. In a typical landed house the tank sits in the roof space and gravity feeds the bathrooms, the water heater and the outdoor taps. The Water Services Industry (Water Reticulation and Plumbing) Rules 2014 set out the basics:
| Rule | What it says, in short | What it means for you |
|---|---|---|
| Rule 46(1) | A storage tank goes between the meter and the taps, except the kitchen tap used for drinking water | The kitchen tap normally comes straight from the main; bathrooms draw from the tank |
| Rule 47(1) | Tanks must be watertight, protected from rodents and insects, reachable for maintenance, with a dust- and mosquito-proof cover and a drain to flush out sediment | A cracked tank, a loose lid or no drain valve is a defect worth fixing |
| Rule 50(2) | Tanks for most buildings hold at least one day’s water demand | The tank is your buffer during a water cut |
| Rule 45 | No pump drawing directly from the public main without a suction tank; a fine of up to RM10,000 | A booster pump must draw from a tank |
Ranhill SAJ said in April 2026 that a premises’ storage tank can last up to 24 hours under normal use (RTM, April 2026). See my guide to water supply disruptions in Johor.
How often should you clean it?
| Benchmark | Frequency | Status |
|---|---|---|
| Private houses in Malaysia | None set by law | SPAN said in May 2024 that the Water Services Industry Act 2006 (Act 655) does not cover cleaning tanks on private property, and that a proposed safe drinking water law under the Ministry of Health would deal with it. I could not confirm such a law is in force as of November 2026. |
| Master Plumbers Association Malaysia | About once a year | A recommendation. Tanks fed through a maintained filter may need it less often. |
| Kuala Lumpur City Hall public housing | Every six months | What one local authority does for its own flats; a benchmark only. |
| Singapore buildings (for comparison) | At least every 12 months, by a licensed plumber | Compulsory for building owners and MCSTs; landed homes with a tank after the sub-meter are exempt from certification but are still told to clean regularly. |
My practical view: plan on a yearly clean, and look at the cover, overflow pipe and water whenever someone is in the roof space for another job.
When to clean sooner
- After muddy or discoloured water. Sediment from a disruption or pipe repair settles in the tank.
- If something gets in. Plumbers told The Star in November 2024 they had found dead birds, cats, rats and monitor lizards in residential tanks. A bad smell is often the first sign.
- Before you move in. With a subsale or rented house you rarely know when the tank was last cleaned, so one clean at handover gives you a starting point.
- After a long empty period. Water that has stood for months in a vacant home is worth draining and flushing.
Signs your tank needs attention
Clear water does not prove a tank is clean; plumbers find mud, algae, feathers and rust in tanks whose water looked fine. Watch for these:
| What you notice | Possible cause | What to do |
|---|---|---|
| Smell from bathroom taps or showers | Something decaying in the tank, or stagnant water | Have the tank inspected and cleaned |
| Brown or gritty water upstairs but not at the kitchen tap | Sediment in the tank, or rust from old steel pipes | Clean the tank; see plumbing problems in older homes |
| Water dripping from an outside overflow pipe | A float valve that does not shut off | Fix the float valve; Ranhill SAJ names roof-tank overflow as one cause of high bills |
| Stains on the ceiling under the tank | Overflow, a cracked tank or a leaking joint | Fix quickly; see damp and wall seepage |
| Mosquitoes in the roof space or bathrooms | A missing or loose cover | Fit a cover that seals properly |
To check for a hidden leak, Ranhill SAJ suggests reading your meter at night when no one is using water and again before anyone uses it in the morning. If the reading moved, water is going somewhere. My guide to electricity and water bills in JB explains the tariff.
Safety: why most owners should not do it themselves
- Falls. Access is usually a ceiling hatch and a ladder. Only the roof members carry weight; a foot on a plasterboard ceiling goes straight through.
- Heat. Roof spaces under a tropical sun get very hot by late morning. Go early and never alone.
- Weight. A litre of water weighs about a kilogram, so a 1,000-litre tank holds about a tonne. Draining it the wrong way can flood a ceiling.
- Enclosed spaces. DOSH’s Industry Code of Practice for Safe Working in a Confined Space 2010 lists storage tanks as confined spaces and, for workers, calls for an entry permit, gas testing, trained entrants and a standby person outside. A small house tank is usually cleaned from the opening, but nobody should climb into a large tank alone.
- Chemicals. Never mix cleaning products. If a disinfectant is used, ask what it is and how the tank will be rinsed before use.
Who does it, and what a proper job looks like
Most JB owners use a plumber or a tank-cleaning service; I don’t recommend any particular one. Ranhill SAJ’s website has a Registered Plumbers page, which is worth checking if pipes, valves or the tank may need replacing. Ask for a written quote that lists the steps, what happens if repairs are found and who removes the sludge, plus before-and-after photos. I have not found a reliable, dated price range for Johor, so compare at least two quotes; the price depends on tank size, access and repairs.
- Prepare. Keep drinking water from the kitchen tap in containers and plan for a few hours without tank water.
- Isolate. Close the inlet valve and switch off any booster pump so it does not run dry.
- Drain. Use the drain valve, leaving a little water to wash out sediment, as the specialist quoted by The Star described.
- Scrub. Remove sediment and slime with a sponge, brush, water jet or scraper, depending on the tank material.
- Flush and inspect. Flush out the dirty water, then check the float valve, overflow, outlets, cover, cracks and rust.
- Refill and run the taps. Let the tank fill, run each tap and shower until clear, and clean shower heads and aerators.
Looking at a landed home in JB?
Tell me the area and your budget. When we view, I ask the owner where the tank is, when it was last cleaned and how the house coped with the last water cut.
WhatsApp JasonCovers, filters and other upgrades
- A cover that fits. The Master Plumbers Association said many plastic tank covers fit poorly or are left partly open. A sealed cover keeps out dirt, rats and Aedes mosquitoes. Under the Destruction of Disease-Bearing Insects Act 1975 (Act 154), a first offence can mean a fine of up to RM10,000, up to two years’ jail, or both, and owner and occupier can both be liable. See my mosquito and dengue guide, and rats and cockroaches at home.
- A pre-tank filter. A point-of-entry filter traps sediment before it reaches the tank, which can stretch the time between cleanings if the filter is backwashed and maintained. My tap water and filters guide compares the types.
- Replacing or moving a tank. A bigger or relocated tank adds load to the roof. Get an engineer’s view and check whether the council must approve the work (see my renovation permit guide).
For a yearly upkeep budget, see landed home running costs, and roof leaks for the roof space around the tank.
Condos and rented homes
Condos and strata schemes. Water is usually stored in tanks at ground level and on the roof, then pumped to the units. Under the Strata Management Act 2013 the joint management body (JMB) or management corporation (MC) maintains common property, which may include the tanks and pumps, paid from your maintenance fees and sinking fund. Ask when the tanks were last cleaned and check the AGM minutes for water complaints; see checking condo management and individual water meters in Johor condos.
Rented houses. The tenancy agreement decides. Often the landlord pays for tank cleaning and repairs to the tank and pipes, while the tenant reports smells, leaks and dirty water promptly. See who pays for repairs and my tenancy agreement guide.
What I check on a landed viewing
| Check | What to ask or look for |
|---|---|
| Tank location and access | Where it is and whether there is a safe hatch |
| Tank condition | Material and age, a cover that fits, no cracks, rust or overflow |
| Ceiling below | Stains or patched ceiling boards under the tank |
| Taps upstairs | Colour, smell and pressure |
| Records | When the tank was last cleaned; any filters and service dates |
| Area history | How the house coped with recent water cuts |
Raise any problem before you make an offer. See subsale house inspection and questions to ask at a subsale viewing.
Where to buy if this matters to you
- Skudai, Tampoi and Kempas: many older terraces; check tank and pipe condition.
- Tebrau, Setia Indah and Molek: established neighbourhoods with a mix of house ages.
- Mount Austin: popular with families, with newer landed phases nearby.
- Bukit Indah and Gelang Patah: gated landed estates near the Second Link.
- Iskandar Puteri: newer townships with semi-Ds and bungalows.
- Kulai and Senai: larger landed homes further from the city.
Compare them on my JB property map. Foreigners can generally buy Johor homes only from RM1 million, with only limited exceptions (for example, some serviced apartments sold by developers with state approval); no area is exempt as a whole. See Johor’s foreigner minimum price.
More Johor living guides: Tap water and filters in JB · Water supply disruptions in Johor · Mosquitoes and dengue at home · Landed home running costs
Frequently asked questions
How often should I clean the water tank of a landed house in Malaysia?
About once a year is a sensible plan, as the Master Plumbers Association Malaysia suggested in November 2024. Clean sooner after muddy water, pipe repairs or a long empty period, or if anything gets into the tank.
Is there a law on cleaning house water tanks in Malaysia?
No law sets a cleaning frequency for private houses; SPAN said in May 2024 that Act 655 does not cover cleaning tanks on private property. The 2014 plumbing rules do require tanks to be watertight, covered against dust and mosquitoes, reachable for maintenance and fitted with a drain.
Can I clean my rooftop water tank myself?
Only if the tank is small, easy to reach and you can work safely. Roof spaces are hot, ceiling boards will not hold your weight and 1,000 litres of water weighs about a tonne. Most owners hire a plumber.
Who cleans the water tanks in a condo?
The joint management body or management corporation maintains common property under the Strata Management Act 2013, which may include the tanks and pumps. Ask the management office when they were last cleaned.
Who pays for water tank cleaning in a rented house?
The tenancy agreement decides. Often the landlord pays for tank cleaning and repairs, while the tenant reports problems promptly. Put it in writing before the tenancy starts.
Is water from the roof tank used for drinking?
Under the 2014 plumbing rules the kitchen drinking tap is normally fed straight from the main, while the tank supplies bathrooms and other taps. You still shower and brush your teeth with tank water, so keep the tank clean.
What are the signs that my water tank needs cleaning?
A smell from bathroom taps, brown or gritty water upstairs, sediment in shower heads, mosquitoes in the roof space or a stained ceiling below the tank. Clear water alone does not prove the tank is clean.
Buying or renting a landed home in JB?
Tell me the area, the type of house and your budget. When we view, I check where the water tank is, ask the owner when it was last cleaned and how the house coped with recent water cuts, and point out ceiling stains or overflow pipes worth a closer look. You can also book an appointment for viewings, or a Zoom consultation if you are still abroad.
Sources: The Star, “Don’t neglect water tanks”, 17 November 2024; The Star, “Regular cleaning a must for high-rise water tanks”, 13 May 2024; Water Services Industry (Water Reticulation and Plumbing) Rules 2014, P.U.(A) 36/2014, gazetted 30 January 2014, rules 45 to 50 (legislation record via UNEP LEAP), checked November 2026; Ranhill SAJ, Frequently Asked Questions (high bills, roof-tank overflow, meter leak test, registered plumbers), accessed November 2026; RTM Berita, Johor Bahru, Kota Tinggi and Pontian 23-hour water disruption on 21 and 22 April, 15 April 2026; PUB Singapore, Water Storage Tanks requirements, accessed November 2026; Department of Occupational Safety and Health (DOSH), Industry Code of Practice for Safe Working in a Confined Space 2010, accessed November 2026; Attorney General’s Chambers, Laws of Malaysia: Destruction of Disease-Bearing Insects Act 1975 (Act 154), Water Services Industry Act 2006 (Act 655) and Strata Management Act 2013 (Act 757), checked November 2026
Jason Lim, REN 84424, IQI Realty Sdn. Bhd. E (1) 1584/6. General information checked on 15 November 2026, not legal, plumbing or engineering advice. Rules and guidance change; get a qualified plumber to inspect and clean your tank, and confirm with Ranhill SAJ, SPAN, your council or the management office before you commit.