FEATURES 17
The anatomy of a geyser
Compiled by
Tanya Olckers with technical input from Ariston , Kwikot , Advanced Valves and ECASA
Geysers are regulated through the National Regulator for Compulsory Specifications ( NRCS ).
Before we begin , it goes without saying that the installation of a geyser or water heater be done only by a qualified and competent plumber .
Geysers are regulated . Regulation VC9006 requires any person that manufactures , imports or sells water heaters must have a Letter of Authority ( LOA ) issued by the NRCS . This LOA is product / model specific and has a validity of three years .
Image supplied by Ariston
Water heaters , commonly referred to in South Africa as geysers , are tested in accordance with SANS 151 : ‘ Fixed Electric Storage Water Heaters ’. Typical tests include energy efficiency ( they must be ‘ B ’ rated ), resistance to fatigue failure , hot water output and corrosion resistance .
The electrical safety is tested in accordance with SANS / IEC 60335-2- 21 : ‘ Safety of household and similar electrical appliances – particular requirements for storage water heaters ’.
This is an international safety testing system that makes allowance for each country / region to have national deviations . In South Africa these deviations are the requirement for a Temperature and Pressure safety valve ( T & P valve ), maximum system pressure of 600kPa and installation according to SANS 10254 : ‘ Installation , replacement and repair of hot water systems ’.
Issuing of a LOA is conditional on compliance with SANS 151 and SANS 60335-2-21 . This LOA is of utmost importance .
Geysers are supplied complete with a thermostat , heating element , T & P valve and drain cock ( for emptying ). For enamelled steel water heaters there is also a sacrificial anode fitted .
Thermostats are required to comply with SANS 181 : Thermostats for electric storage water heaters – these thermostats have an adjustable control range from 30 – 70 degrees and a fixed safety cut-out around 100 degrees depending on their design . The safety cut-out must be manually reset after it has operated . It is a requirement that the geyser is tested to SANS 60335-2-21 with this compliant thermostat . There is a notice on the geyser that requires ‘ like for like ’ component replacement to ensure safety integrity .
Heating elements are required to comply with SANS 514 : ‘ Immersion heaters for electric storage water heaters ’. It is a requirement that the water heater is tested to SANS 60335-2-21 with this compliant heating element . There is a notice on the water heater that requires like-for-like component replacement to ensure safety integrity .
Geysers are highly regulated .
T & P valves are required to comply with SANS 198 : ‘ Functional – control valves and safety valves for domestic hot and cold-water systems ’. It is a regulatory requirement that the safety valve is supplied with the water heater . The safety valve determines the maximum operating pressure of the system and must be matched to the operating pressure of the water heater . It is a requirement that the water heater is tested to SANS 60335-2-21 with this compliant safety valve . There is a notice on the water heater that requires likefor-like component replacement to ensure safety integrity .
Drain cocks are required to comply with SANS 1808-53 : ‘ Drain cocks for hot water storage containers ’. It is a requirement that the water heater is tested to SANS 60335-2-21 with this compliant drain cock . There is a notice on the water heater that requires like-for-like component replacement to ensure safety integrity .
What types of water heaters are available
Electric water heaters are designed to be connected to an AC 230v electrical supply . They are available in sizes 50l to 300l with 150l being the most used . Element ratings vary from 2kW to 4kW . Most water heaters available in South Africa are renewable energy ready and can be connected to solar panels and heat pumps .
Gas water heaters in South Africa are generally of the instantaneous variety ( heat water on demand with no storage tank ). They are available from 5l / min to 40l / min and can be open flue self-igniting or forced induction with electronic temperature regulation . Gas appliances must have safety permits and must be installed by licensed gas installers .
Solar water heaters can be direct or indirect ( for frost prone environments ) and are available from 100l to 300l . Solar water heaters can also work as electric water heaters without solar panels .
April 2025 Volume 31 I Number 02 www . plumbingafrica . co . za