EN 60335-2-21, “Household and similar electrical appliances – Safety – Part 2-21: Particular requirements for storage water heaters”, sets the safety requirements for electric appliances that heat water below boiling temperature and store it. It is read together with EN IEC 60335-1; Part 2-21 holds the rules that are added or changed for these appliances. Its focus is that the hot water container under pressure and the heater stay safe when something fails.
Let us take care of EN 60335-2-21 testing and the CE marking of your product together; CE Danışmanı (CE Consultant) manages the whole process.
EN 60335-2-21 at a glance
| Edition cited in the EU Official Journal | EN 60335-2-21:2021 |
|---|---|
| Official title | Household and similar electrical appliances – Safety – Part 2-21: Particular requirements for storage water heaters |
| Legislation supported | Low Voltage Directive 2014/35/EU |
| Type of standard | Product standard |
Products covered
The standard applies to electric storage water heaters for household and similar use. Typical examples:
- Closed (pressurised) water heaters
- Open-outlet and vented storage heaters
- Small under-sink and over-sink heaters
- Vertical and horizontal wall-mounted heaters and floor-standing heaters
- Hot water cylinders fitted with an electric heater
Instantaneous water heaters, which heat water as it flows, belong to EN 60335-2-35. Kettles and similar appliances are assessed with EN 60335-2-15.
Particular requirements for storage water heaters
- Thermostat and thermal cut-out: A thermostat controls the water temperature; if it fails, a non-self-resetting thermal cut-out that works independently of it switches the heater off.
- Pressure strength: The container of a closed heater must withstand a water pressure above its rated pressure without leaking or permanent damage.
- Pressure relief: Closed heaters have a pressure relief device, or the installation instructions require one and explain how the discharge pipe is connected.
- Dry operation: Switching the appliance on without water must not cause fire, electric shock or dangerous damage.
- Protection against moisture: An appliance installed in a bathroom needs an enclosure with a suitable degree of protection against dripping and splashing water.
- Earthing and fixing: The metal container is reliably connected to the protective conductor, and the wall fixing must carry the heater filled with water.
- Marking and instructions: Rated pressure, capacity and installation conditions are marked; the instructions cover discharge, draining and maintenance.
Typical test programme
EN 60335-1 and EN 60335-2-21 are applied together. The programme differs for closed and open-outlet heaters.
| Test or check | What is verified? |
|---|---|
| Power input | The rated input is within the permitted deviation |
| Heating test | Temperatures of cords, terminals and outer surfaces stay within limits |
| Leakage current and electric strength | Insulation is adequate at operating temperature and after the humidity test |
| Water ingress (IP) test | Dripping or splashing water does not reach live parts |
| Container pressure test | The container does not leak or deform permanently |
| Abnormal operation | The thermal cut-out opens with the thermostat short-circuited; dry operation creates no hazard |
| Fixing strength | The wall fixing is not damaged under load |
Water spray tests follow the method of IP testing.
Place in the CE marking process
- Risk assessment: Hazards of electric shock, scalding, rupture of the container and fire are identified for the type of heater.
- Design: The thermal cut-out, the relief device and the container construction are chosen to meet the standard.
- Verification and testing: The sample is tested to EN 60335-1 and EN 60335-2-21; EMC tests are done separately.
- Technical file: Test reports, diagrams, the list of critical components and the instructions go into the technical file.
- Declaration of conformity: EN 60335-2-21 is listed among the standards applied and the CE marking is affixed.
Compliance with the harmonised standard gives presumption of conformity with the relevant essential requirements of the Low Voltage Directive. Turkey applies the same rules through its own aligned regulation.
Standards applied together
- EN 55014-1 and EN 55014-2: EMC emission and immunity of household appliances
- EN 60335-2-35: instantaneous water heaters
- RoHS: restriction of hazardous substances
- Ecodesign and energy labelling rules: efficiency and labelling of water heaters are assessed separately
Frequently asked questions
Is EN 60335-2-21 enough on its own?
No. Part 2-21 is applied together with EN 60335-1 and the test report covers both. EMC, RoHS and efficiency rules are assessed separately.
Must the safety valve be supplied with the heater?
A closed heater must have pressure relief. If the valve is not supplied, the installation instructions state clearly what kind of device has to be fitted.
Which edition applies?
The edition cited in the EU Official Journal is EN 60335-2-21:2021. Check the current citation before testing starts.
Other standards in this group
- EN 62477-1: Power Electronic Converters
- EN 60335-2-15: Appliances for Heating Liquids
- EN 60335-2-24: Refrigerating Appliances
- EN 60335-2-30: Room Heaters
