December 2026 brings two things that are hard on home plumbing in the Klang Valley: heavy rain and an empty house. Rain tests your gutters, drains and waterproofing. Year-end school holidays mean many homes sit empty for days, so a small leak can run unnoticed. A few checks in late November and early December can save you a stained ceiling or a nasty surprise when you get back.
Before the heavy rain
Heavy rain through the year makes blocked gutters, overflowing drains and failed waterproofing common causes of ceiling stains here. Before the wettest weeks:
- Clear gutters and downpipes of leaves and silt, from the ground or a stable ladder with someone holding it. Do not walk on the roof.
- Check where each downpipe empties. It should run into a drain that can take the water, not onto the porch.
- Clear outdoor drains around the house. Our guide on an outdoor drain overflowing after rain explains what to check and when to report a public drain to the council.
- Clear the balcony drain in a condo, so rainwater does not pool against the door.
- Look at your ceilings below the roof and bathrooms, and note any stains now so you can tell if they grow.
If a stain appears after rain, read Roof Leak or Pipe Leak? to work out where the water is coming from.
Before you travel
An empty house is when a dripping hose or running cistern does the most damage, because nobody sees it.
- Know where your main valve is. In a landed house it is the stopcock near the meter. In a condo it is usually your unit valve. Our guide on how to turn off your main water supply shows where to look.
- Close the main supply if the house will be empty for several days and nobody needs water while you are away.
- Switch off the water heater at its switch.
- Switch off the booster pump, so it cannot run dry or keep starting because of a small leak.
- Close the angle valves under sinks and toilets if you are not closing the main supply.
Top up floor traps
Every floor trap holds a little water that stops sewer smells coming up. In an empty house, that water evaporates. Pour a jug of water into every floor trap, including balconies and service yards, before you go. A small splash of cooking oil on top slows evaporation. Our guide on a bad smell from a drain or floor trap explains why.
Landed house or condo unit
| Check | Landed house | Condo unit |
|---|---|---|
| Gutters and outdoor drains | Yours to clear | Building management |
| Roof tank and pump | Yours: check tank, switch pump off | Building management |
| Balcony drain | Yours | Yours |
| Main valve | Stopcock near the meter | Your unit valve |
| Ceiling leak from above | Not applicable | Report to building management |
In a condo, tell the management office if you will be away for a long time, and leave a contact number in case of a leak from the unit above.
When you come back
- Open the main valve slowly and let taps run until the water is clear.
- Switch the pump and heater back on once water is flowing.
- Check ceilings for new stains.
- Run a meter test. Close every tap, read the meter, wait a few hours, and read it again. Our Water Meter Leak Test Calculator turns the readings into litres per day.
When to call a plumber
Call a plumber if you find a leak after the meter, a cistern that keeps running, or a pump that will not move water when you return. For stains that clearly follow the rain, you need a roofer or waterproofing contractor. The Roof Leaks and Waterproofing section explains the options. For anything else that turns up, start from the home plumbing guide for KL homes, which lists every problem by section.
Ready for the rain? Read the Roof Leaks and Waterproofing section