Questions to Ask Before Installing a Backup Tank

Getting a backup tank installed is a meaningful investment — systems for a typical Johannesburg home typically run from R20,000 for a basic tank-and-pump setup to around R55,000 for a whole-house solution. That range is wide enough to hide a lot of variation in quality, scope, and long-term reliability. The questions below are designed to expose that variation before you commit, not after.

1. How did you size the tank and pump for my household?

This is the first question to ask, and the answer tells you immediately whether the installer has actually thought about your property or is quoting a one-size-fits-all package.

A competent installer should ask you: how many people live in the house, what your peak-demand periods look like, whether you want the tank to cover cooking and drinking only or full household use including showers and toilets, and whether the tank will be fed from the municipal supply, a borehole, or both. South Africans use on average about 237 litres of water per person per day — above the world average of roughly 173 litres — so a family of four has meaningfully different needs to a retired couple.

If the installer quotes a tank size without asking any of those questions, treat that as a warning sign.

On pump sizing: the pump needs to deliver adequate flow rate and pressure to every outlet you expect it to serve. Ask for the specific litres-per-minute figure they are designing to, and ask what happens if two showers run simultaneously. Undersized pumps are one of the most common causes of dissatisfied backup-system owners.

2. What exactly triggers the switchover, and is it automatic?

There are broadly two approaches: manual switchover and automatic switchover. Manual is cheaper upfront but means someone has to notice the municipal supply has dropped and physically flip a valve or switch. In practice, this often means you discover the tank is running low at 6 am when there is no municipal pressure to refill it.

An automatic switchover system uses a pressure sensor or float valve to detect that municipal supply has dropped below a set threshold, and diverts the pump to draw from the tank without any human intervention. Ask the installer:

• At what pressure or flow level does the system switch over?
• How quickly does it switch back when municipal supply resumes?
• Does the controller have a low-tank cutoff to protect the pump from running dry?

The last point matters more than most homeowners realise. Running a pump dry destroys the motor. A reputable installer will include a dry-run protection device as standard; if it is listed as an optional extra, ask why.

3. What is and is not included in the quoted price?

This is where quoted prices diverge most dramatically. Get a written, itemised scope of work before you agree to anything. Specifically ask whether the following are included:

• The tank itself (capacity and material — JoJo, poly, or steel)
• The pump and its installation
• All pipework, fittings, and connection to your existing plumbing
• The electrical connection and any DB-board work required
• The switchover controller or float valve assembly
• First-fill water, if applicable
• Commissioning and testing
• Removal and disposal of any existing equipment being replaced

It is not unusual for a low headline quote to exclude the electrical work, the pipework modifications, or even the tank itself. Confirm every line item in writing.

Sizing, switchover, scope — a good installer answers all of these upfront. Compare 3 free quotes — vetted installers, no obligation.

4. What warranties apply, and who honours them?

Ask separately about:

Product warranties — the tank manufacturer’s warranty (typically covering structural integrity) and the pump manufacturer’s warranty on parts and motor. Ask for the actual warranty documents, not just a verbal reassurance.

Installation warranty — the installer’s own guarantee on their workmanship. This covers leaks at joints, incorrect installation of the controller, and similar. Ask how long it runs and what the call-out process is if something fails in the first year.

Also ask: if the pump fails during the warranty period, does the installer come out to diagnose and remove it, or do you have to deal with the manufacturer directly? The answer reveals how much after-sales support you are actually buying.

5. Are you registered and insured, and can you show me?

Plumbing and electrical work in South Africa must be carried out by registered tradespeople. Plumbers should be registered with the Plumbing Industry Registration Board (PIRB). Any electrical work on the DB board or new circuits must be done by a registered electrician who issues a Certificate of Compliance (CoC). Ask for both before any work begins.

Also ask whether the installer carries public liability insurance. If a water leak from the installation damages your ceilings, floors, or a neighbour’s property, you need to know whose insurance responds.

Our guide on how to choose a backup water installer covers the registration and vetting process in more detail if you want to go deeper on this point.

6. How will the water quality be maintained in the tank?

Stored water can develop bacterial growth if the tank is not properly designed, positioned, and maintained. Ask:

• Is the tank opaque (UV-resistant) to prevent algae growth?
• Is it sealed against insects and debris?
• Does the design allow for periodic drainage and cleaning?
• If the tank feeds drinking water or kitchen outlets, what treatment or filtration is included?

If the system is intended to supply potable water, the water delivered to your taps should meet SANS 241 — the South African drinking-water quality standard. Ask the installer how their system design supports that, and what ongoing maintenance the system requires to stay compliant.

Ready to put these questions to real installers in your area? Get 3 no-obligation quotes from vetted Johannesburg contractors.

7. What does ongoing maintenance look like, and what does it cost?

A backup water system is not a fit-and-forget installation. Pumps need periodic servicing, tank inlets and outlets need inspection, and pressure switches can drift out of calibration over time. Before you sign, ask:

• What is the recommended service interval?
• Do you offer a maintenance contract, and what is the annual cost as a rough guide?
• What are the most common failure points on the specific equipment you are installing?
• If the pump fails at 9 pm on a Sunday, what is your response time?

None of these questions should be uncomfortable for a competent installer to answer. If you are met with vague reassurances rather than specific answers, that tells you something useful about what post-installation support will actually look like.

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The overall cost of a backup tank-and-pump system is significant enough that a few direct questions upfront are well worth the slight awkwardness. An installer who welcomes the questions and answers them specifically is almost always a better choice than one who rushes past them.