A solar powered geyser can save you thousands of rands a year by using the sun's energy to heat your water, but only if you use it well. This guide covers the daily habits, maintenance, and safety points that make the real difference to how much hot water (and how much money) you get out of your system.
Your solar geyser consists of a 150-litre solar tank and 20 vacuum tubes. Water from the tank passes through the manifold at the top, where the tubes fit in, and is heated as it circulates back into the tank for storage and later use. In winter, with fewer sunlight hours, electricity tops up the heating until the thermostat's set temperature (factory default: 36°C) is reached. Track how this affects your usage with our prepaid electricity meter guide.
Hose down the vacuum tubes from time to time to clear off dust for the best heating results. Clean tubes let more sunlight reach the water, meaning more free heating and lower electricity costs.
A solar geyser can't heat water at night, so how you use hot water during the day makes a real difference to what's left by evening:
These habits matter most in winter, when water takes longer to heat.
A pressure control valve manages the water pressure feeding into your house and the solar feed pipe as the system heats and cools. More than a few litres of water release a day from this valve usually indicates a problem worth reporting.
Shutting off the system: turn the red knob to close off water into the house and solar system.
A separate overflow safety valve releases built-up steam pressure in hot weather: a slow drip here is normal and won't show on your water meter, but a constant stream can point to a thermostat fault. Also keep an eye out for low water pressure, humming or cracking sounds, or water running down your gutter when it isn't raining; all signs your geyser may need attention.
Always check that the geyser switch or circuit breaker on your DB board is in the ON (up) position. If it's off, you won't have any hot water supply, and switching it off doesn't save electricity. See our electrical safety tips for more on working safely around your DB board.
Your 150l solar geyser can heat water to very high temperatures. Never let small children run their own bath water or operate the tap without supervision for optimal geyser safety.
Report it to client services for repair if you notice water leaking from the solar system on the roof, or see cracked or broken vacuum tubes. Never attempt to work on or adjust your solar geyser yourself because installation and maintenance must comply with plumbing and SANS regulations. Always arrange repairs through the Cosmopolitan team, who will send a qualified installer.
With Cosmopolitan Projects, your home is built to comply with the latest energy-efficient standards, helping you get maximum electricity savings from your solar geyser.
Keep the vacuum tubes clean and dust-free, limit hot water use in the afternoon so there's more left for the evening, and shower rather than bathe where possible.
This is normal. The overflow safety valve releases built-up steam pressure in hot weather, uses minimal water, and won't show up on your water meter. A constant stream of water or steam can signal a thermostat fault.
The pressure control valve manages water pressure feeding into your house and the solar feed pipe as the system heats and cools. More than a few litres a day from this valve usually indicates a problem. The red knob shuts off water into the house and solar system entirely.
Shower instead of bathing, run hot water first in the bath before adding cold water, use cold water for chores like the kettle, and bath or shower in the evening to give the sun a full day to heat the tank.
No. Solar geysers can heat water to very high temperatures, so children should never run their own bath water or use the tap unsupervised.
Report it to Cosmopolitan client service for repair. Don't attempt to fix or adjust the system yourself, it must be serviced by a qualified installer to comply with plumbing and SANS regulations.
This depends on whether your home has a backup inverter system as well as a solar geyser, not every development includes both, so check your handover documentation or installation test report sheet to confirm what your home has. The standard Cosmopolitan backup system (a Sunsynk 5kW inverter with a 5.12kWh battery) has more than enough power capacity to run a geyser element where both are present, which usually draws 3000–4000W.
Battery capacity is the real limit: a geyser running continuously would use up a 5.12kWh battery in around 1.5 hours. Because a solar geyser relies on the sun for most of its heating, the electric element only needs to run for shorter top-up periods, making it easier to support on backup power than a fully electric geyser. See our inverter backup system guide for how backup power works in your home.