Water Outages? How to Keep Your Taps Running
Planned maintenance, burst pipes and supply problems mean water cuts that last hours or even days are now a regular event in many parts of South Africa, Gauteng especially. A storage tank with a booster pump keeps your taps, showers, toilets and geyser running through an outage, at proper pressure. Here’s how the setup works and how to size it.
How a backup water system works
- A storage tank fills from the municipal supply through a float valve, so it is full when the water goes off.
- A booster pump next to the tank pushes the water into the house at a steady 2.5 to 3.5 bar. Water flowing down from a tank on a stand gains only about 0.1 bar per metre of height, far too little for a shower, so the pump is what makes it work.
- A controller starts the pump when a tap opens, stops it when the tap closes, and stops it if the tank runs dry.
- Valves: a ball valve and strainer before the pump, a non-return valve after it, and a bypass so the house can run straight from the municipal supply while the pump is serviced.
The house draws from the tank all the time, not only during outages, so the water in the tank is constantly refreshed.
What size tank do you need?
A household uses about 200 litres per person per day with normal use. This is roughly how long a full tank lasts:
| Household | Normal daily use | 2,500 L tank | 5,000 L tank |
|---|---|---|---|
| 2 people | about 400 L | about 6 days | about 12 days |
| 4 people | about 800 L | about 3 days | about 6 days |
| 6 people | about 1,200 L | about 2 days | about 4 days |
Skip the garden, baths and full washing machine loads during an outage and the water lasts a lot longer.
Which pump?
Size the booster pump by how many taps run at the same time:
- Flat, cottage or 1 bathroom: 0.37 kW
- 2 to 3 bathrooms, single storey: 0.55 to 0.75 kW
- 4 or more bathrooms, or a double storey: 1.1 kW
The simplest option is a booster pump combo: pump, automatic flow controller, wiring and plug, assembled and tested so you connect it to your tank and switch it on. The controller also stops the pump if the tank runs dry. For the quietest, steadiest pressure, choose a VSD pump. Our booster pump size guide has the full calculation.
Power cuts and load shedding
A booster pump needs electricity, and water cuts don’t wait for the power to be on. A 0.37 kW combo runs on most 1.5 to 3 kVA inverters. A 0.75 kW combo needs about 3 kVA because of the start-up surge, and a VSD booster is gentler on an inverter. With no inverter, the SQB250 solar booster pump combo runs off solar panels: a 250W, 24V DC pump with its controls, pressure tank and fittings (panels not included).
Tips for when the water goes off
- Clean the strainer after a long outage. When the supply comes back it often carries air and sediment, and the strainer before the pump catches the dirt.
- If the pump keeps cutting out, the tank is probably empty or the pump has lost prime. The controller reads both as a dry run. Let the tank refill, fill the pump with water and restart it.
- Check the float valve now and then. If it sticks, the tank won’t refill when the water comes back.
Frequently asked questions
Can I connect a booster pump straight to the municipal supply?
Many municipalities don’t allow a pump connected directly to the mains, and it won’t help during a water cut anyway. Put the pump after a storage tank that fills from the municipal supply. Check your municipality’s by-laws.
Will my geyser work from the tank?
Yes. The pump feeds the whole house, geyser included. Keep the pressure under about 4 bar: more can damage geysers, mixers and toilet valves.
Do I need a plumber?
The pump side is simple: a combo arrives assembled, wired and with a plug, so you connect the suction to the tank and the delivery to the house, fill the pump with water and plug it in. Fitting the float valve, the bypass and the connection into your house plumbing is a job for a plumber.
What pump do I need for a double storey?
Usually 1.1 kW. Allow roughly 0.3 bar extra for every 3 m the highest shower sits above the pump.
Get your backup water sorted
Tell us how many people live in the house, how many bathrooms you have and whether it’s a single or double storey. WhatsApp us on 012 881 1962 and we’ll match the pump for you, free, with delivery anywhere in South Africa. Weak pressure even when the water is on? Read low water pressure: 8 causes and how to fix them.