Moving Into a House Left Empty? Clean the Tank and Sump First

You have bought, inherited or rented a house in Bangalore that has been shut for months. The keys work, the paint is fine, and the taps run. Before anyone in the family drinks from them, deal with the water storage. A tank and sump that have sat with water in them, or sat closed and dusty, are not the same as ones in daily use.

What happens in an unused tank and sump

Water that does not move goes stale. Sediment settles into a layer on the floor of the tank. Dust, insects and leaves find their way in through any gap in the lid or any open vent. If sunlight reaches a poorly covered tank, growth on the walls is more likely. A sump is worse, because it is underground, dark and often forgotten. Nobody has looked inside it since the last tenant or the last owner.

None of this is dramatic, and it is not always visible. That is the point. Clear-looking water can still have been sitting in a dirty container for months.

Check this on day one

• Open the overhead tank lid and look. Is there water left, a sludge layer, floating debris or a smell?
• Open the sump cover, if you can do so safely, and look at the water level and colour.
• Check that tank lids close fully and that the overflow pipe and vent have a mesh. Our guide on the overflow pipe and mosquito mesh explains why.
• Run a tap into a clear glass. Note the colour and smell. If you see yellow or smell something off, read yellow, smelly tank water.
• Look for leaks at the tank base, pipe joints and the pump area while the system is empty.

The order that works

1. Switch off the pump and drain the overhead tank. Let the stale water go. Do not push it back down the line.
2. Empty the sump. Pump out or bail out the old water and the sediment at the bottom.
3. Scrub and rinse both. Walls and floor, not just the water line. Remove the loosened sludge, do not just rinse it around.
4. Fix what you found. Missing lid, torn mesh, a cracked wall or a leaking pipe joint should be sorted before refilling.
5. Refill and flush the lines. Run every tap and shower until the water at the outlet is clear and smells normal. Do the same for the geyser and any filter lines.
6. Re-check after a day. Look at the water in a clear glass again. If it is still off, something upstream needs another look.

Do it before the furniture comes in

An empty house is the easiest time to do this. There is nothing to move, nobody is waiting for water, and you can leave the tank open to dry. Once the family has moved in, every cleaning day means disrupted water, covered floors and a lot of questions. Do it in the gap between getting the keys and the moving truck.

If you are also dealing with damp walls or old leaks in a house that has been shut for a long time, look at those at the same stage. See our damp check for resale homes and the tank cleaning frequency guide, so you set a cleaning schedule from day one.

Where LoklFix fits

We clean overhead tanks and sumps, check the lids, mesh and joints while we are there, and tell you straight what we find. If we see a leak or a damp wall on the way, we say so. You do not have to commit to anything else. Visits are usually this week, so the water is sorted before you move in.

Frequently asked questions