الهيئة السعودية للمواصفاتوالمقاييس والجودة   
Saudi Standards, Metrology and Quality Org (SASO)  
 
 
 
 
 
 
 
 
 
SASO /FDS/IEC  60335 -2-21:2021  
IEC 60335 -2-21:2018  
 
 
 
 
 
 
الأجهزة الكهربائية المنزلية وما شابهها - السلامة –الجزء 2-21: متطلبات
خاصة بالسخانات الكهربائية التخزينية  
Household and similar electrical appliances - Safety - Part 2 -21: 
Particular requirements for storage water heaters  
 
 
 
 
ICS: 91.140. 065 
 
THIS DOCUMENT IS A DRAFT AMENDEMENT T O SAUDI  STANDARD 
CIRCULATED FOR CO MMENT. IT IS, THEREFORE SUBJECT  TO 
CHANGE AND MAY NOT BE REFERRED UNTIL APPROVED BY THE  
BOARD OF DIRECTORS.  SASO STANDARD                                                  SASO IEC 60335 -2-21:2021  
 
 Foreword  
Saudi Standards, Metrology and Quality Organization (SASO) has  adopted Standard No. ( IEC 
60335 -2-21) “Household  and similar electrical appliances - Safety - Part 2 -21: Particular 
requirements for storage water heaters " issued by ( IEC) in English. This standard has been 
approved as a Saudi Standard with national  modifications.  
 
This SASO IEC 60335 -2-21:202 0 standard is a modified adoption of International Standard 
IEC 60335 -2-21:2018, (Household and similar electrical appliances - Safety - Part 2 -21: 
Particular requirements for storage water heaters). Standard has been varied as indicated to 
take account of  Kingdom of Saudi Arabia conditions. The modifications are specified in 
Annex BB.  
 
This Standard supersedes and replaces (SASO -GSO -1858: Storage -type electric water heaters 
for household use) and (SASO -GSO -1859: Methods of test for storage -type electric w ater 
heaters for household use) and (SASO -1698: Safety of household and similar electrical 
appliances – Part 2: Particular requirments – Section 21: Storage water heaters)  and (SASO -
UL-174:  Household Electric Storage Tank Water Heaters ). 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 SASO STANDARD                                                  SASO IEC 60335 -2-21:2021  
 
 Annex BB: List of National modifications  
(Normative)  
The text of the international Standard IEC 60335 -2-21:2018 was approved by Saudi 
Standards, Metrology and Quality Organization as a Saudi Standard with agreed 
national modification as indicated below:  
NO Clause/  Subclause  as 
specified in : IEC 60335 -
2-21:2018 Edition 6.1  Addition  / Modification  
1 22  Construction       22.103   " After 1st paragraph "  
 Add:  
For increasing the safety, the closed storage water heaters shall be 
provided with one of the following two means :  
 Additional pressure relief device installed at the top of the container 
separated from the openings for water connections and shall prevent 
the pressure in the container from exceeding the rated pressure by more 
than 0.2 MPa.   
 A temperature and pressure relief valve “T & P valve”, installed at the 
top of the container, or with its centre line in the upper 15 cm of the 
side. This valve shall be installed separated from the openings for 
water connections.  
The temperature and pressure relief valve shall prev ent the w ater 
temperature from exceeding 99 ˚C, and shall prevent the pressure in the 
container from exceeding the rated pressure by more than 0.2 MPa . The T 
& P valve shall be connected with a suitable drainage tubing.  
NOTE  The temperature and pressure re lief valve shall be tested 
according to annex BD. 
Add the following new sub -clause  
22.112    Pilot lamp  
The water heater that have bottom water connection shall be provided with 
a pilot lamp which shall be connected in parallel with the heating unit, to 
indicate the cutting -in and cutting -out of the electric current in the heating 
unit. 
Compliance is checked by inspection.  
 
Add the following new sub -clause  
22.113    Thermometer  
The water heater that have bottom water connection shall be provided 
with a th ermometer having a suitable scale for indicating the water 
temperature level within the container.  
Compliance is checked by inspection.  SASO STANDARD                                                  SASO IEC 60335 -2-21:2021  
 
  
Add the following new sub -clause   
 
22.114  Container For the Storage - Electric Water Heaters  
22.114.1 Both ends of cylindrical containers shall be domed outwards 
unless the design and gauge  of the bottom are sufficient to ensure equal 
mechanical strength when domed  inwards.  
22.114.2 Cathodic protection  each steel container shall be provided with 
at least one magnesium anode having a mass of magnesium of not less 
than 200 g per square meter of container area. The anode, which shall be 
capable of being replaced, shall be electrically connected to the container.  
The mass of the magnesium anode may be less than 200 g per sq uare meter 
of container area, if the manufacturer provided evidence that the suggested 
mass is adequate to protect the container for not less than 2 years.  
 
Add the following new sub -clause  
22.115     Thermostat  
A water heater shall be provided with a tem perature regulating thermostat 
or control and be subjected to the water temperature test specified in 
22.115.1. The heater complies when the control or thermostat that controls 
each heating element limits the water temperature to 85°C or less.  
22.115.1 Compliance is checked  by the water heater  is to be operated as 
described in clause 11, and the temperature of the water at the water outlet 
is to be measured as water is drawn off immediately following the second 
opening of the temperature -regulating therm ostats.  
 
 
 
 
 
 
 
 
 
 
 
 SASO STANDARD                                                  SASO IEC 60335 -2-21:2021  
 
 Annex BD  
TEST OF TEMPERATURE AND PRESSURE RELIEF VALVE (T & 
P VALVE)  FOR CLOSED STORAGE WATER HEATERS  
 
AD.1  The water heater is installed as in normal use and be filled with water to its rated 
capacity.  
AD.2 The temperature relief mechanism and pressure relief mechanism shall be tested 
separately as follows:  
AD.2.1 For temperature relief mechanism  
AD.2.1.1 The thermostat and thermal cut -out are short -circuited, so as the water heater 
continue in operation without switching off during the test.  
AD.2.1.2 The pressure relief device installed on the cold water inlet pipe is removed, and the 
water heater is    directly connected to the water supply, the hot water outlet pipe 
being opened. The apparatus shown in Figure 1 being install ed on the hot water 
outlet. The cold water shut -off valve is opened until the water flowing to the 
outside through the mentioned apparatus.  
AD.2.1.3 The water heater is operated until the temperature and pressure relief device starts 
to relief. The tempera ture at which the valve starts to relief shall be recorded.  
AD.2.1.4 The recorded temperature has to be ≤ 99oC. In case the valve does not relief, this 
means that this valve is failed to pass the test.  
AD.2.2 For pressure relief mechanism  
AD.2.2.1 The water heater is switched off.  
AD.2.2.2 The pressure relief device installed on the cold water inlet pipe is removed and 
replaced by a connection to a hydraulic pump supplied with water from a special 
source, provided with a pressure gauge and a facility to  increase the pressure 
gradually up to 0.5 MPa  above the rated pressure of the water heater.  
AD.2.2.3 The shut -off valve is closed and the pump is operated to increase the pressure 
gradually until the  temperature and pressure relief valve starts to relief . The pressure 
read on the pressure gauge at which that valve starts to relief is recorded.  
AD.2.2.4 The recorded pressure has to be ≤ the rated pressure of the water heater 0.2 MPa . In 
case the valve does not relief, this means that this valve is failed t o pass the test.