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Ariston Next Evo X 16 Natural Gas Instantaneous Water Heater 3632533 — 16 L/min Room Sealed Multipoint ErP A 27kW
Ariston Next Evo X 16 Natural Gas Instantaneous Water Heater 3632533 — 16 L/min Room Sealed Multipoint ErP A 27kW
The Ariston Next Evo X 16 Natural Gas (MPN 3632533) is a room-sealed gas instantaneous water heater delivering 16 litres per minute of continuous hot water from a natural gas (G20) mains supply. With a maximum heat output of 27.4kW and the highest ErP water heating load profile (XL), it is designed for larger domestic properties and light commercial applications with high simultaneous hot water demand — hotels, offices, care facilities, and multi-bathroom homes. Compact at just 187mm deep, it installs in cupboards and utility rooms close to an external wall. Features oxygen-free copper heat exchanger, lean-rich low NOx burner, ECO mode, built-in temperature stabilisation, LED touch display, post-ventilation, and flame ionisation ignition. ErP water heating energy efficiency Class A (ηWH 80.5%). Minimum inlet pressure 0.2 bar. 2-year warranty. Flue kit sold separately — see MPN 3319648.
⚠ Gas Safe Registered Installation Required — Must be installed by a Gas Safe registered engineer in accordance with the manufacturer's installation manual, Gas Safety (Installation and Use) Regulations 1998, and current British Standards. The appliance requires a 230V / 50Hz mains electrical supply for ignition — a fused spur must be provided. A 60/100mm coaxial flue kit is required and must be purchased separately if not already available (see MPN 3319648 below).
ℹ Natural Gas Model — ErP XL Load Profile
This unit is factory-set for natural gas (G20) and achieves the highest ErP declared load profile XL, indicating suitability for very high demand applications with daily fuel consumption of 24.8 kWh. For LPG (off-grid), order the Next Evo X 11 LPG (MPN 3632535). An Ariston-approved gas conversion kit is available if conversion between gas types is later required — Gas Safe registered installation only.
This unit is factory-set for natural gas (G20) and achieves the highest ErP declared load profile XL, indicating suitability for very high demand applications with daily fuel consumption of 24.8 kWh. For LPG (off-grid), order the Next Evo X 11 LPG (MPN 3632535). An Ariston-approved gas conversion kit is available if conversion between gas types is later required — Gas Safe registered installation only.
16 L/min
Nominal flow rate
27.4 kW
Max heat output
0.2 bar
Min inlet pressure
187 mm
Depth only
ErP A / XL
Energy rated
Features & Benefits
✔ Oxygen-Free Copper Heat Exchanger
The oxygen-free copper heat exchanger delivers heat from the burner to the water more efficiently than standard copper, with superior resistance to corrosion and scaling over time. Oxygen-free copper contains a minimum of 99.99% copper with virtually no dissolved oxygen — eliminating the micro-porosity that causes conventional copper to oxidise internally over years of hot water contact. The result is a heat exchanger with a longer operating life and more consistent thermal performance across the product's service life.
✔ Low NOx Lean-Rich Burner — ErP Class A
The lean-rich staged combustion burner reduces nitrogen oxide (NOx) emissions to 45–47 mg/kWh — significantly below the ErP threshold for Class A rating. In a lean-rich burner the primary zone operates with excess air (lean) and the secondary zone with rich mixture — this staged approach lowers peak flame temperatures, which are the primary driver of thermal NOx formation. Water heating energy efficiency ηWH is rated at Class A across both models, meeting the ErP Regulation 814/2013 requirements for instantaneous gas water heaters.
✔ ECO Mode — Built-In Temperature Stabilisation
ECO mode limits the output temperature to a 35–45°C band — ideal for summer use when incoming cold water is warmer and less heat input is needed, reducing gas consumption without the burner over-firing and cycling. The built-in temperature stabilisation system compensates for fluctuations in mains water pressure and incoming cold water temperature, maintaining a consistent output temperature regardless of draw-off rate. This prevents the "cold sandwich" effect common in basic instantaneous heaters where temperature drops when flow rates change.
✔ Post-Ventilation & Overheat Sensor — Electronic Ignition
The post-ventilation system continues the fan for a period after burner shut-off — purging residual combustion gases from the heat exchanger and flue before the appliance returns to standby, reducing flue gas condensate formation and improving heat exchanger longevity. An overheat sensor shuts the appliance down safely if water temperature exceeds safe limits. The electronic ignition with flame ionisation replaces the standing pilot light — ignition only fires when hot water is drawn, eliminating continuous pilot gas consumption and reducing the risk of ignition failure.
✔ 16 L/min — High Demand Multi-Point
At 16 L/min nominal flow, the Next Evo X 16 can supply multiple simultaneous draw-off points — a shower and basin running concurrently, or back-to-back use by multiple occupants without the temperature dipping between uses. With a maximum heat output of 27.4kW and ErP load profile XL, it is the highest-capacity model in the Next Evo X range and is suited to properties that would otherwise require a large unvented cylinder. Despite this output, it remains compact at 187mm deep with an identical face size to the 11L model.
Technical Specifications — Next Evo X 16 Natural Gas (3632533)
| MPN | 3632533 |
| Gas Type | Natural gas — G20 |
| Gas Category | II2H3P — I3B/P |
| Appliance Type | Room-sealed instantaneous (Type C13/C33) |
| Nominal DHW Flow Rate | 16 L/min |
| Minimum DHW Flow Rate | 2.5 L/min |
| Max. Nominal Heat Input | 30.0 kW |
| Max. Nominal Heat Output | 27.4 kW (G20) |
| Min. Nominal Heat Output | 8.7 kW (G20) |
| DHW Temp Range | 35°C – 65°C |
| Water Pressure — Min / Max | 0.2 bar / 10 bar |
| ErP Water Heating Class | A — ηWH 80.5% — Load profile XL |
| NOx Emissions | 47 mg/kWh |
| Noise Level | 63 dB(A) |
| Power Supply | 230V / 50Hz — 44W consumption — internal fuse 3.15A |
| IP Rating | IPX4D |
| Flue Connection | 60/100mm coaxial — flue kit sold separately (3319648) |
| Dimensions (H × W × D) | 570 × 345 × 187 mm |
| Dry Weight | 15 kg |
| Warranty | 2 years manufacturer's warranty |
Frequently Asked Questions
What does 16 litres per minute mean in practice?
The 16 L/min nominal flow rate is the volume of hot water the heater can deliver per minute at the rated temperature rise. For a typical temperature rise from 12°C cold to 40°C output (a comfortable shower temperature), 16 L/min is sufficient for simultaneous use at two points — for example, a shower and a basin, or two bathrooms in sequence — making it well-suited to larger properties with higher simultaneous demand. Minimum activation flow is just 2.5 L/min, so even low-flow taps and eco shower heads will trigger the burner without issue. The heater will deliver hot water at any flow rate between 2.5 L/min and 16 L/min continuously.
Can this heater be converted to LPG?
This unit is factory-set for natural gas (G20). Ariston do offer conversion kits for the Next Evo X range allowing conversion between natural gas and LPG, but gas conversion must only be carried out by a Gas Safe registered engineer and must use the correct Ariston-approved conversion kit. The appliance gas category is II2H3P/I3B/P, meaning it is certified for use on both gas families — but the burner injectors, gas valve calibration, and pressure settings must all be correctly adjusted for the target gas. Using an incorrect gas type or unconverted injectors will result in incorrect combustion, CO risk, and will void the warranty. Contact Ariston or your distributor for the correct conversion kit code.
Do I need a flue kit, and which one?
Yes — the Next Evo X is a room-sealed (Type C) appliance that draws combustion air from and discharges flue gases to the outside through a 60/100mm coaxial flue system. A flue kit is not included with the water heater and must be purchased separately. For a standard installation through a wall to the outside, the Ariston Horizontal Flue Kit 60/100 (SE) MPN 3319648 is the correct flue kit — it includes all components needed for a normal through-wall horizontal termination up to 800mm. For vertical terminations, or for installations requiring extensions, elbows, or bends, additional Ariston flue accessories are available. All flue components used must be Ariston-approved and compatible with the 60/100mm SE coaxial system.
What is the minimum water pressure required?
The Next Evo X has an exceptionally low minimum inlet water pressure of just 0.2 bar — far lower than the 0.5–1.0 bar minimum required by many competing instantaneous heaters. This makes it particularly suitable for properties with poor mains pressure, gravity-fed systems, and loft or rural installations where mains pressure can be marginal. Maximum working pressure is 10 bar. If the incoming pressure is above 3 bar, a pressure-reducing valve should be fitted upstream to protect the appliance and any downstream fittings.
Is the mains electricity connection mandatory?
Yes — the Next Evo X requires a 230V / 50Hz mains electrical supply for the electronic ignition system, the modulating gas valve, the fan, the LED display, and the flame ionisation detection circuit. The appliance draws 44W during operation. A fused spur (typically 3A fused) must be provided by a Part P registered electrician adjacent to the installation position. The appliance cannot operate without mains power — it is not suitable for off-grid locations without a generator or battery inverter supply. The internal fuse is rated 3.15A.
What warranty does the Next Evo X carry?
The Ariston Next Evo X carries a 2-year manufacturer's warranty as standard. Warranty claims require the installation to have been carried out by a Gas Safe registered engineer and in accordance with the Ariston installation manual. The appliance must be installed, commissioned, and maintained in accordance with the manufacturer's instructions, Gas Safety (Installation and Use) Regulations, and applicable British Standards. Ariston UK can be contacted via their website for warranty registration and support.
$253.67
Original: $724.77
-65%Ariston Next Evo X 16 Natural Gas Instantaneous Water Heater 3632533 — 16 L/min Room Sealed Multipoint ErP A 27kW—
$724.77
$253.67More Images
Ariston Next Evo X 16 Natural Gas Instantaneous Water Heater 3632533 — 16 L/min Room Sealed Multipoint ErP A 27kW
The Ariston Next Evo X 16 Natural Gas (MPN 3632533) is a room-sealed gas instantaneous water heater delivering 16 litres per minute of continuous hot water from a natural gas (G20) mains supply. With a maximum heat output of 27.4kW and the highest ErP water heating load profile (XL), it is designed for larger domestic properties and light commercial applications with high simultaneous hot water demand — hotels, offices, care facilities, and multi-bathroom homes. Compact at just 187mm deep, it installs in cupboards and utility rooms close to an external wall. Features oxygen-free copper heat exchanger, lean-rich low NOx burner, ECO mode, built-in temperature stabilisation, LED touch display, post-ventilation, and flame ionisation ignition. ErP water heating energy efficiency Class A (ηWH 80.5%). Minimum inlet pressure 0.2 bar. 2-year warranty. Flue kit sold separately — see MPN 3319648.
⚠ Gas Safe Registered Installation Required — Must be installed by a Gas Safe registered engineer in accordance with the manufacturer's installation manual, Gas Safety (Installation and Use) Regulations 1998, and current British Standards. The appliance requires a 230V / 50Hz mains electrical supply for ignition — a fused spur must be provided. A 60/100mm coaxial flue kit is required and must be purchased separately if not already available (see MPN 3319648 below).
ℹ Natural Gas Model — ErP XL Load Profile
This unit is factory-set for natural gas (G20) and achieves the highest ErP declared load profile XL, indicating suitability for very high demand applications with daily fuel consumption of 24.8 kWh. For LPG (off-grid), order the Next Evo X 11 LPG (MPN 3632535). An Ariston-approved gas conversion kit is available if conversion between gas types is later required — Gas Safe registered installation only.
This unit is factory-set for natural gas (G20) and achieves the highest ErP declared load profile XL, indicating suitability for very high demand applications with daily fuel consumption of 24.8 kWh. For LPG (off-grid), order the Next Evo X 11 LPG (MPN 3632535). An Ariston-approved gas conversion kit is available if conversion between gas types is later required — Gas Safe registered installation only.
16 L/min
Nominal flow rate
27.4 kW
Max heat output
0.2 bar
Min inlet pressure
187 mm
Depth only
ErP A / XL
Energy rated
Features & Benefits
✔ Oxygen-Free Copper Heat Exchanger
The oxygen-free copper heat exchanger delivers heat from the burner to the water more efficiently than standard copper, with superior resistance to corrosion and scaling over time. Oxygen-free copper contains a minimum of 99.99% copper with virtually no dissolved oxygen — eliminating the micro-porosity that causes conventional copper to oxidise internally over years of hot water contact. The result is a heat exchanger with a longer operating life and more consistent thermal performance across the product's service life.
✔ Low NOx Lean-Rich Burner — ErP Class A
The lean-rich staged combustion burner reduces nitrogen oxide (NOx) emissions to 45–47 mg/kWh — significantly below the ErP threshold for Class A rating. In a lean-rich burner the primary zone operates with excess air (lean) and the secondary zone with rich mixture — this staged approach lowers peak flame temperatures, which are the primary driver of thermal NOx formation. Water heating energy efficiency ηWH is rated at Class A across both models, meeting the ErP Regulation 814/2013 requirements for instantaneous gas water heaters.
✔ ECO Mode — Built-In Temperature Stabilisation
ECO mode limits the output temperature to a 35–45°C band — ideal for summer use when incoming cold water is warmer and less heat input is needed, reducing gas consumption without the burner over-firing and cycling. The built-in temperature stabilisation system compensates for fluctuations in mains water pressure and incoming cold water temperature, maintaining a consistent output temperature regardless of draw-off rate. This prevents the "cold sandwich" effect common in basic instantaneous heaters where temperature drops when flow rates change.
✔ Post-Ventilation & Overheat Sensor — Electronic Ignition
The post-ventilation system continues the fan for a period after burner shut-off — purging residual combustion gases from the heat exchanger and flue before the appliance returns to standby, reducing flue gas condensate formation and improving heat exchanger longevity. An overheat sensor shuts the appliance down safely if water temperature exceeds safe limits. The electronic ignition with flame ionisation replaces the standing pilot light — ignition only fires when hot water is drawn, eliminating continuous pilot gas consumption and reducing the risk of ignition failure.
✔ 16 L/min — High Demand Multi-Point
At 16 L/min nominal flow, the Next Evo X 16 can supply multiple simultaneous draw-off points — a shower and basin running concurrently, or back-to-back use by multiple occupants without the temperature dipping between uses. With a maximum heat output of 27.4kW and ErP load profile XL, it is the highest-capacity model in the Next Evo X range and is suited to properties that would otherwise require a large unvented cylinder. Despite this output, it remains compact at 187mm deep with an identical face size to the 11L model.
Technical Specifications — Next Evo X 16 Natural Gas (3632533)
| MPN | 3632533 |
| Gas Type | Natural gas — G20 |
| Gas Category | II2H3P — I3B/P |
| Appliance Type | Room-sealed instantaneous (Type C13/C33) |
| Nominal DHW Flow Rate | 16 L/min |
| Minimum DHW Flow Rate | 2.5 L/min |
| Max. Nominal Heat Input | 30.0 kW |
| Max. Nominal Heat Output | 27.4 kW (G20) |
| Min. Nominal Heat Output | 8.7 kW (G20) |
| DHW Temp Range | 35°C – 65°C |
| Water Pressure — Min / Max | 0.2 bar / 10 bar |
| ErP Water Heating Class | A — ηWH 80.5% — Load profile XL |
| NOx Emissions | 47 mg/kWh |
| Noise Level | 63 dB(A) |
| Power Supply | 230V / 50Hz — 44W consumption — internal fuse 3.15A |
| IP Rating | IPX4D |
| Flue Connection | 60/100mm coaxial — flue kit sold separately (3319648) |
| Dimensions (H × W × D) | 570 × 345 × 187 mm |
| Dry Weight | 15 kg |
| Warranty | 2 years manufacturer's warranty |
Frequently Asked Questions
What does 16 litres per minute mean in practice?
The 16 L/min nominal flow rate is the volume of hot water the heater can deliver per minute at the rated temperature rise. For a typical temperature rise from 12°C cold to 40°C output (a comfortable shower temperature), 16 L/min is sufficient for simultaneous use at two points — for example, a shower and a basin, or two bathrooms in sequence — making it well-suited to larger properties with higher simultaneous demand. Minimum activation flow is just 2.5 L/min, so even low-flow taps and eco shower heads will trigger the burner without issue. The heater will deliver hot water at any flow rate between 2.5 L/min and 16 L/min continuously.
Can this heater be converted to LPG?
This unit is factory-set for natural gas (G20). Ariston do offer conversion kits for the Next Evo X range allowing conversion between natural gas and LPG, but gas conversion must only be carried out by a Gas Safe registered engineer and must use the correct Ariston-approved conversion kit. The appliance gas category is II2H3P/I3B/P, meaning it is certified for use on both gas families — but the burner injectors, gas valve calibration, and pressure settings must all be correctly adjusted for the target gas. Using an incorrect gas type or unconverted injectors will result in incorrect combustion, CO risk, and will void the warranty. Contact Ariston or your distributor for the correct conversion kit code.
Do I need a flue kit, and which one?
Yes — the Next Evo X is a room-sealed (Type C) appliance that draws combustion air from and discharges flue gases to the outside through a 60/100mm coaxial flue system. A flue kit is not included with the water heater and must be purchased separately. For a standard installation through a wall to the outside, the Ariston Horizontal Flue Kit 60/100 (SE) MPN 3319648 is the correct flue kit — it includes all components needed for a normal through-wall horizontal termination up to 800mm. For vertical terminations, or for installations requiring extensions, elbows, or bends, additional Ariston flue accessories are available. All flue components used must be Ariston-approved and compatible with the 60/100mm SE coaxial system.
What is the minimum water pressure required?
The Next Evo X has an exceptionally low minimum inlet water pressure of just 0.2 bar — far lower than the 0.5–1.0 bar minimum required by many competing instantaneous heaters. This makes it particularly suitable for properties with poor mains pressure, gravity-fed systems, and loft or rural installations where mains pressure can be marginal. Maximum working pressure is 10 bar. If the incoming pressure is above 3 bar, a pressure-reducing valve should be fitted upstream to protect the appliance and any downstream fittings.
Is the mains electricity connection mandatory?
Yes — the Next Evo X requires a 230V / 50Hz mains electrical supply for the electronic ignition system, the modulating gas valve, the fan, the LED display, and the flame ionisation detection circuit. The appliance draws 44W during operation. A fused spur (typically 3A fused) must be provided by a Part P registered electrician adjacent to the installation position. The appliance cannot operate without mains power — it is not suitable for off-grid locations without a generator or battery inverter supply. The internal fuse is rated 3.15A.
What warranty does the Next Evo X carry?
The Ariston Next Evo X carries a 2-year manufacturer's warranty as standard. Warranty claims require the installation to have been carried out by a Gas Safe registered engineer and in accordance with the Ariston installation manual. The appliance must be installed, commissioned, and maintained in accordance with the manufacturer's instructions, Gas Safety (Installation and Use) Regulations, and applicable British Standards. Ariston UK can be contacted via their website for warranty registration and support.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
The Ariston Next Evo X 16 Natural Gas (MPN 3632533) is a room-sealed gas instantaneous water heater delivering 16 litres per minute of continuous hot water from a natural gas (G20) mains supply. With a maximum heat output of 27.4kW and the highest ErP water heating load profile (XL), it is designed for larger domestic properties and light commercial applications with high simultaneous hot water demand — hotels, offices, care facilities, and multi-bathroom homes. Compact at just 187mm deep, it installs in cupboards and utility rooms close to an external wall. Features oxygen-free copper heat exchanger, lean-rich low NOx burner, ECO mode, built-in temperature stabilisation, LED touch display, post-ventilation, and flame ionisation ignition. ErP water heating energy efficiency Class A (ηWH 80.5%). Minimum inlet pressure 0.2 bar. 2-year warranty. Flue kit sold separately — see MPN 3319648.
⚠ Gas Safe Registered Installation Required — Must be installed by a Gas Safe registered engineer in accordance with the manufacturer's installation manual, Gas Safety (Installation and Use) Regulations 1998, and current British Standards. The appliance requires a 230V / 50Hz mains electrical supply for ignition — a fused spur must be provided. A 60/100mm coaxial flue kit is required and must be purchased separately if not already available (see MPN 3319648 below).
ℹ Natural Gas Model — ErP XL Load Profile
This unit is factory-set for natural gas (G20) and achieves the highest ErP declared load profile XL, indicating suitability for very high demand applications with daily fuel consumption of 24.8 kWh. For LPG (off-grid), order the Next Evo X 11 LPG (MPN 3632535). An Ariston-approved gas conversion kit is available if conversion between gas types is later required — Gas Safe registered installation only.
This unit is factory-set for natural gas (G20) and achieves the highest ErP declared load profile XL, indicating suitability for very high demand applications with daily fuel consumption of 24.8 kWh. For LPG (off-grid), order the Next Evo X 11 LPG (MPN 3632535). An Ariston-approved gas conversion kit is available if conversion between gas types is later required — Gas Safe registered installation only.
16 L/min
Nominal flow rate
27.4 kW
Max heat output
0.2 bar
Min inlet pressure
187 mm
Depth only
ErP A / XL
Energy rated
Features & Benefits
✔ Oxygen-Free Copper Heat Exchanger
The oxygen-free copper heat exchanger delivers heat from the burner to the water more efficiently than standard copper, with superior resistance to corrosion and scaling over time. Oxygen-free copper contains a minimum of 99.99% copper with virtually no dissolved oxygen — eliminating the micro-porosity that causes conventional copper to oxidise internally over years of hot water contact. The result is a heat exchanger with a longer operating life and more consistent thermal performance across the product's service life.
✔ Low NOx Lean-Rich Burner — ErP Class A
The lean-rich staged combustion burner reduces nitrogen oxide (NOx) emissions to 45–47 mg/kWh — significantly below the ErP threshold for Class A rating. In a lean-rich burner the primary zone operates with excess air (lean) and the secondary zone with rich mixture — this staged approach lowers peak flame temperatures, which are the primary driver of thermal NOx formation. Water heating energy efficiency ηWH is rated at Class A across both models, meeting the ErP Regulation 814/2013 requirements for instantaneous gas water heaters.
✔ ECO Mode — Built-In Temperature Stabilisation
ECO mode limits the output temperature to a 35–45°C band — ideal for summer use when incoming cold water is warmer and less heat input is needed, reducing gas consumption without the burner over-firing and cycling. The built-in temperature stabilisation system compensates for fluctuations in mains water pressure and incoming cold water temperature, maintaining a consistent output temperature regardless of draw-off rate. This prevents the "cold sandwich" effect common in basic instantaneous heaters where temperature drops when flow rates change.
✔ Post-Ventilation & Overheat Sensor — Electronic Ignition
The post-ventilation system continues the fan for a period after burner shut-off — purging residual combustion gases from the heat exchanger and flue before the appliance returns to standby, reducing flue gas condensate formation and improving heat exchanger longevity. An overheat sensor shuts the appliance down safely if water temperature exceeds safe limits. The electronic ignition with flame ionisation replaces the standing pilot light — ignition only fires when hot water is drawn, eliminating continuous pilot gas consumption and reducing the risk of ignition failure.
✔ 16 L/min — High Demand Multi-Point
At 16 L/min nominal flow, the Next Evo X 16 can supply multiple simultaneous draw-off points — a shower and basin running concurrently, or back-to-back use by multiple occupants without the temperature dipping between uses. With a maximum heat output of 27.4kW and ErP load profile XL, it is the highest-capacity model in the Next Evo X range and is suited to properties that would otherwise require a large unvented cylinder. Despite this output, it remains compact at 187mm deep with an identical face size to the 11L model.
Technical Specifications — Next Evo X 16 Natural Gas (3632533)
| MPN | 3632533 |
| Gas Type | Natural gas — G20 |
| Gas Category | II2H3P — I3B/P |
| Appliance Type | Room-sealed instantaneous (Type C13/C33) |
| Nominal DHW Flow Rate | 16 L/min |
| Minimum DHW Flow Rate | 2.5 L/min |
| Max. Nominal Heat Input | 30.0 kW |
| Max. Nominal Heat Output | 27.4 kW (G20) |
| Min. Nominal Heat Output | 8.7 kW (G20) |
| DHW Temp Range | 35°C – 65°C |
| Water Pressure — Min / Max | 0.2 bar / 10 bar |
| ErP Water Heating Class | A — ηWH 80.5% — Load profile XL |
| NOx Emissions | 47 mg/kWh |
| Noise Level | 63 dB(A) |
| Power Supply | 230V / 50Hz — 44W consumption — internal fuse 3.15A |
| IP Rating | IPX4D |
| Flue Connection | 60/100mm coaxial — flue kit sold separately (3319648) |
| Dimensions (H × W × D) | 570 × 345 × 187 mm |
| Dry Weight | 15 kg |
| Warranty | 2 years manufacturer's warranty |
Frequently Asked Questions
What does 16 litres per minute mean in practice?
The 16 L/min nominal flow rate is the volume of hot water the heater can deliver per minute at the rated temperature rise. For a typical temperature rise from 12°C cold to 40°C output (a comfortable shower temperature), 16 L/min is sufficient for simultaneous use at two points — for example, a shower and a basin, or two bathrooms in sequence — making it well-suited to larger properties with higher simultaneous demand. Minimum activation flow is just 2.5 L/min, so even low-flow taps and eco shower heads will trigger the burner without issue. The heater will deliver hot water at any flow rate between 2.5 L/min and 16 L/min continuously.
Can this heater be converted to LPG?
This unit is factory-set for natural gas (G20). Ariston do offer conversion kits for the Next Evo X range allowing conversion between natural gas and LPG, but gas conversion must only be carried out by a Gas Safe registered engineer and must use the correct Ariston-approved conversion kit. The appliance gas category is II2H3P/I3B/P, meaning it is certified for use on both gas families — but the burner injectors, gas valve calibration, and pressure settings must all be correctly adjusted for the target gas. Using an incorrect gas type or unconverted injectors will result in incorrect combustion, CO risk, and will void the warranty. Contact Ariston or your distributor for the correct conversion kit code.
Do I need a flue kit, and which one?
Yes — the Next Evo X is a room-sealed (Type C) appliance that draws combustion air from and discharges flue gases to the outside through a 60/100mm coaxial flue system. A flue kit is not included with the water heater and must be purchased separately. For a standard installation through a wall to the outside, the Ariston Horizontal Flue Kit 60/100 (SE) MPN 3319648 is the correct flue kit — it includes all components needed for a normal through-wall horizontal termination up to 800mm. For vertical terminations, or for installations requiring extensions, elbows, or bends, additional Ariston flue accessories are available. All flue components used must be Ariston-approved and compatible with the 60/100mm SE coaxial system.
What is the minimum water pressure required?
The Next Evo X has an exceptionally low minimum inlet water pressure of just 0.2 bar — far lower than the 0.5–1.0 bar minimum required by many competing instantaneous heaters. This makes it particularly suitable for properties with poor mains pressure, gravity-fed systems, and loft or rural installations where mains pressure can be marginal. Maximum working pressure is 10 bar. If the incoming pressure is above 3 bar, a pressure-reducing valve should be fitted upstream to protect the appliance and any downstream fittings.
Is the mains electricity connection mandatory?
Yes — the Next Evo X requires a 230V / 50Hz mains electrical supply for the electronic ignition system, the modulating gas valve, the fan, the LED display, and the flame ionisation detection circuit. The appliance draws 44W during operation. A fused spur (typically 3A fused) must be provided by a Part P registered electrician adjacent to the installation position. The appliance cannot operate without mains power — it is not suitable for off-grid locations without a generator or battery inverter supply. The internal fuse is rated 3.15A.
What warranty does the Next Evo X carry?
The Ariston Next Evo X carries a 2-year manufacturer's warranty as standard. Warranty claims require the installation to have been carried out by a Gas Safe registered engineer and in accordance with the Ariston installation manual. The appliance must be installed, commissioned, and maintained in accordance with the manufacturer's instructions, Gas Safety (Installation and Use) Regulations, and applicable British Standards. Ariston UK can be contacted via their website for warranty registration and support.
