Does Switching Off Your Geyser Save Electricity? (Eskom Loadshedding Guide)

Quick answer

Yes — switching off your geyser saves electricity, but less than most people think. A well-insulated modern geyser only loses 2–4°C per hour when off, so the savings come from heating less water overall, not from "stopping" standby heat loss.

Realistic saving: 10–25% off your monthly bill if your geyser is the biggest electrical load in your home (which it usually is — 30–50% of household consumption).

How a geyser actually uses electricity

An electric geyser only draws power when:

1. The water inside has dropped below the thermostat setpoint (usually 60°C)
2. It is actively heating back up

It does not draw power continuously. A well-insulated 150L geyser typically cycles on for 30–60 minutes every 4–8 hours when nobody is using hot water.

When switching off saves money

• You are away for a day or more — definitely turn it off
• You only shower in the morning — switch off after your shower, switch on 2 hours before next use
• Your geyser is old or poorly insulated — losses are higher, so off-time savings are bigger
• You are on a time-of-use tariff (some municipalities) — switch off during peak hours

When switching off does not save much

• The geyser is well-insulated and you use hot water all day
• You switch it on for an hour just before showering — it will not fully reheat, so you will end up with lukewarm water and frustration
• You forget and leave it off for 3 days then panic-switch it on at 4kW for hours

The smart approach: timer or controller

Rather than manually flipping the DB switch:

• R150 mechanical timer — set it to come on 1–2 hours before you shower and off again
• R800–R2,500 Geyserwise / smart controller — schedule by day, monitor energy use, integrate with solar
• Solar geyser or heat pump — biggest long-term saving but R20,000+ upfront

Safety: do not do this

• Never switch a geyser on if it has been drained or emptied — element burns out instantly
• Do not leave the geyser off for weeks in winter without draining — risk of Legionella bacteria multiplying in stagnant warm water
• Do not set the thermostat below 55°C — Legionella risk again

Loadshedding tip

During Stage 4+ loadshedding, switch off your geyser at the DB during your power-off slots and leave it off for an hour after power returns — this stops your geyser from being the first thing slamming the grid when power comes back and helps the area stabilise.

Need help with your geyser?

If your geyser runs hot constantly, trips the DB, or you are thinking about a timer install, get a plumber to look.

Find a geyser plumber near you →