What Products It Covers
EN 15502 applies to gas-fired central heating boilers fitted with atmospheric burners, fan-assisted atmospheric burners or fully premixed burners. It covers appliances of types B and C that use the three gas families at the pressures given in EN 437, with water temperature not exceeding 105 °C in normal operation. This includes the wall-hung boilers and combi (heating plus hot-water) boilers widely installed across Europe.
The Part 1 / Part 2 Structure
| Document | Content | How it is used |
|---|---|---|
| EN 15502-1 | General requirements and tests: construction, safety, fitness for purpose, rational use of energy, classification, marking and energy labelling | Always applies; the base of the technical file |
| EN 15502-2-x | Specific standards grouped by appliance type (for example type C and certain type B appliances), nominal heat input up to 1 000 kW | Applied together with Part 1 for the matching type |
The standard is deliberately split: Part 1 holds the requirements common to every boiler, and the Part 2 documents carry the provisions that depend on how a boiler draws air and discharges products. Always identify the exact appliance type (the type definitions are given in EN 1749) before selecting the Part 2 document, and confirm the current edition and amendments with your test laboratory.
EN 15502 consolidated and replaced the older generation of separate boiler standards (such as those for type B and type C boilers, hot-water supply and condensing boilers). If an older technical file cites those withdrawn numbers, it should be reviewed against the current EN 15502 parts.
The Key Tests
| Test area | What is verified |
|---|---|
| Gas tightness | Leakage of the gas circuit and connections at the relevant test pressures |
| Heat input | Rated and reduced input against gas category, including adjustment range |
| Combustion | CO (and, where required, NOx) in the products, flame stability and sooting across pressures and gas categories |
| Flame failure | Cut-off and re-ignition behaviour of the flame-supervision system |
| Ignition | Reliable ignition and cross-lighting, including fan-assisted and premixed operation |
| Temperature limits | Surface, component and water-side temperature limits and the safety temperature cut-out |
| Hydraulic side | Water pressure, flow, resistance and, for combi boilers, hot-water delivery and temperature stability |
| Efficiency | Useful efficiency and rational use of energy, including condensing operation and condensate handling |
EN 15502 vs EN 26 vs EN 30
| Product | Standard | Decisive feature |
|---|---|---|
| Central heating / combi boiler | EN 15502 family | Provides space heating (water up to 105 °C), often plus hot water |
| Tankless water heater (hot water only) | EN 26 | Sanitary hot water, no space-heating circuit |
| Gas cooker / hob / oven | EN 30 family | Cooking function, no heating-water circuit |
The presence of a space-heating function is what moves a product from EN 26 into EN 15502. A combi boiler that also delivers hot water is still a boiler and stays within EN 15502; it is not certified to EN 26.
The Bench That Runs These Tests
Wanhe builds dedicated wall-hung boiler test benches (e.g. WH-BG line) and combi boiler test rigs (WH-CR-Lab) that combine the gas, water and measurement sides in one station: gas tightness and heat input, combustion analysis for CO/NOx, flame-failure timing, ignition checks, water-side pressure and flow, and useful-efficiency calculation. Benches use 0.5-class instruments, support LPG and natural gas, and are supplied as laboratory type-test rigs or automated end-of-line stations with serial-numbered reports for the technical file.
A typical automated sequence follows the same logical order as the standard: the bench first confirms gas tightness, then verifies ignition and cross-lighting, measures heat input at full and reduced rate, samples combustion for CO and NOx across the required gas categories and pressures, times the flame-failure response, and finally records water-side behaviour and useful efficiency. Each step is logged against the boiler’s serial number, and the station holds a fail result until the out-of-tolerance step is corrected. This removes operator-dependent pass/fail decisions and gives the technical file a consistent, traceable record for every unit. The same stored data also supports later warranty review and continuous quality analysis.
Boiler Variants: Heat-Only, System and Combi
Beyond the type B/type C air-and-flue classification, boilers are described by how they deliver heat and hot water, and the test bench must be configured to the variant:
| Variant | Function | Test implication |
|---|---|---|
| Heat-only (regular) | Heats water for the central heating system; hot water often via a stored cylinder | Heating-side performance and efficiency |
| System | Heating with integrated pumping and controls, often paired with a cylinder | Heating performance plus controls checks |
| Combi | Instant hot water and space heating in one appliance | Both heating and hot-water routines, including switching between modes |
A further distinction is condensing versus non-condensing. A condensing boiler recovers latent heat from the products, produces condensate and reaches higher seasonal efficiency; its tests include low-return-temperature operation and condensate handling, and the bench must measure efficiency at the relevant load points. European ecodesign and energy-labelling rules set minimum seasonal efficiency and emissions (including NOx) and define the product information supplied with the boiler. These rules apply in parallel with EN 15502, so a complete declaration addresses both the standard’s tests and the ecodesign requirements. When planning a bench, tell Wanhe the variant, whether it is condensing, the gas categories and the NOx requirements of the destination country; this determines the analyser, water circuit and software modules supplied.
Common Mistakes
- Applying EN 26 to a combi boiler simply because it produces hot water;
- Selecting the wrong Part 2 document by misidentifying the appliance type (check EN 1749);
- Testing combustion without measuring NOx where the target market’s requirements call for it;
- Citing withdrawn predecessor standards in a new declaration;
- Forgetting ecodesign and energy-labelling obligations that apply in parallel with EN 15502.
Specifying a wall-hung or combi boiler test bench?
Send Wanhe your boiler type, burner, gas categories and whether the station is for a laboratory or a multi-station-qc-upgrade-integrated-stove-plant/" title="Production Line">production line. We will propose the EN 15502-aligned configuration with a quotation within 24 hours.
Email: wanhe1718@gmail.com | WhatsApp: +86 18307609558 | Zhongshan (Xiaolan), Guangdong, China
About WANHE TESTING — Zhongshan Wanhe Test Equipment Development Co., Ltd. is a factory-direct B2B manufacturer of custom wall-hung boiler and combi test rigs, gas appliance and water heater test benches, environmental chambers, range hood testers and fatigue machines. CE / ISO 9001 / IEC / EN / GB / RoHS compliant, with custom design in 7–15 days and equipment delivered to manufacturers in 30+ countries.
Published: 2026-10 | Category: Gas Appliance Standards | Cluster E · Article 4