Running costs

What a hot tub actually costs to run in South Africa

Tariffs change every year and vary by municipality, so the useful thing is not a single number — it is the method, and the levers that move it.

The arithmetic

Your monthly electricity cost is roughly:

kWh used per day × your rate per kWh × 30

A well-insulated four-seat hot tub held at 38°C typically draws somewhere between 4 and 9 kWh per day averaged across the year — lower in a Durban summer, considerably higher in a Free State winter. Poorly insulated units with a waterlogged cover can double that.

Find your own rate on your municipal bill or in Eskom’s current tariff schedule, then use the table below rather than trusting any single figure you read online.

Monthly cost at different tariffs

Illustrative figures for comparison between models, not a quotation. Your actual cost depends on your tariff, tariff block, climate, target temperature and how often you open the lid.

The five levers that actually matter

• The cover. More heat leaves through the lid than anywhere else. A well-fitted, locking thermal cover with a gas lifter is the highest-return item on this list. A waterlogged cover is the most common cause of a bill that suddenly doubles — replace it.
• Cabinet insulation. Fully insulated cabinets cost more up front and cost less every month afterwards. On a six-seater the difference over five winters is not marginal.
• Target temperature. Every degree costs. Dropping from 40°C to 37°C makes a visible difference to the bill and very little to the experience.
• Size. Water volume is the thing you are heating. An eight-seat swim spa is not twice a four-seater’s running cost — it is more.
• Smart scheduling. Models with app-controlled or adaptive heating let you hold a lower baseline and bring the tub up before you use it, rather than sitting at 38°C for a Tuesday nobody swims.

What else you will spend

Chemicals: roughly R150 to R400 a month for a domestic tub, lower on models with UV-C sanitation included. Filters: a cartridge every six to twelve months. Water: a drain and refill every three to four months — for a four-seater that is around 1 000 litres, which on most municipal tariffs is a modest amount. Servicing: budget for an annual check.

The zero-electricity option

A wood fired tub has no running cost on the meter at all. You buy or cut wood, and you accept a two to three hour heat-up. For load-shedding-prone areas and off-grid properties, the arithmetic above simply stops applying.