Pipe burst or leak: what to do in the first five minutes, then what

Water is coming out where it should not. Do these five things in this order, and only then start thinking about the cause.

1. Close the main valve. On most Nellore homes that is the gate or ball valve at the overhead tank outlet, or on the down pipe where it enters the house. If you cannot find it or it is seized, go to the tank on the terrace and close the outlet there. For a direct sump or municipal line, the valve near the meter or sump.
2. Switch off the water motor at its MCB or switch. If the motor is on a timer or auto float, it will otherwise keep refilling the tank you are trying to empty.
3. Switch off the geyser at its MCB if the leak is anywhere near it or on the hot line. A geyser with the cold inlet closed and no water in it can damage its element; with water still in it and the leak on the hot side, you do not want it heating.
4. Open a tap below the leak — a bathroom tap on the ground floor, say — to drop the pressure in the pipes and drain the line. The leak will slow or stop.
5. Contain the water. Bucket, towels, move the inverter, the power strip, the carpet. If water is running anywhere near a socket or the switchboard, switch off the main MCB before you touch anything in that room.

Now you are safe and the flow has stopped or slowed to a drip. The next ten minutes are about reading the leak.

Where is it, and what kind?

• A joint weeping — a thread, an elbow, a union. Commonest on GI pipe that has rusted and on CPVC where a joint was not cleaned before solvent. Slow, steady, fixable.
• A split along a pipe — CPVC that was bent, froze (not here), or got hit; GI that has rusted through from inside. Usually a section replacement.
• A pinhole spray — classic old GI, especially on the coastal side where salt air eats it from outside too. One pinhole means more are coming.
• Water through a wall or ceiling with no visible pipe — a concealed line. Do not start chipping tiles. A technician can isolate which line it is by closing valves one by one, and only then open the wall in the right place.
• Water under the sink or basin — usually the waste or the angle valve connector, not a pressure pipe. Less urgent, but still close the angle valve.

Temporary measures that actually hold

With the valve closed and the line drained, dry the pipe. Self-fusing silicone tape wrapped tight under stretch, or a strip of bicycle inner tube with two hose clips, will hold a pinhole or a weeping joint at reduced pressure — open the main valve only a quarter so you have water at low pressure until the repair. M-seal and similar putties need a dry surface and hours to cure, and do not hold on a split under pressure. Nothing sticks to wet, rusty GI; do not waste the afternoon trying.

GI, CPVC or copper — what the repair looks like

GI (galvanised iron). Older homes. The rusted section is cut out and a new piece threaded in, or the run is replaced with CPVC. If one joint has gone, look hard at the rest; GI of the same age fails together.

CPVC. Most homes built in the last twenty years. The damaged section is cut out and a new piece solvent-welded in with couplings. A properly made CPVC joint is stronger than the pipe. It needs to cure before pressure goes back on, so expect the technician to ask you to keep the valve closed for a while after.

Copper. Rare here, mostly on AC and some geyser lines. Soldered or compression repair.

The repair is ₹499 labour on our rate card, pipe and fittings at MRP and shown to you first. A concealed leak adds opening and making good the wall, which is quoted before any cutting.

After the repair

Open the main valve slowly, a quarter at a time, and watch the repair and every other joint on that run for ten minutes. A second weak joint often shows itself the day the first one is fixed, because the pressure is back. Check the ceiling below a day later for fresh damp. Switch the geyser back on only once its cold inlet is open and water runs from the hot tap — never with the tank empty.

Before it happens again

• Find the main valve today, work it once, and tell the household.
• Check the terrace tank's outlet valve is not seized; a seized valve in an emergency is the same as no valve.
• On old GI, plan the swap to CPVC before the next monsoon rather than after the next leak.
• If you are leaving the house for more than a few days, close the main valve and switch off the motor. A leak that starts on day two of a two-week trip is how ceilings come down.

When to call

Any leak you cannot stop with the valve; any water through a wall or ceiling; any GI pinhole (there will be more); and any joint you have tightened once that still weeps — tightening it again cracks it.