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$1,119.36The Story
The Ariston NUOS Plus Wi-Fi 200L Direct (NUOS200 / product code 3820027) is a floor-standing air source heat pump water heater that delivers up to 80% energy savings over a conventional direct cylinder. Its Coefficient of Performance (COP) of 3.10 at 7°C (EN 16147) means every 1 kWh of electricity generates the equivalent of 3.1 kWh of heat — absorbed from ambient air down to -10°C. The 200-litre titanium-enamelled steel tank reaches 55°C from cold in under 4 hours, one of the fastest heat-up times on the market. Built-in Wi-Fi via the Aqua Ariston Net app provides full remote control and scheduling, while Plug & Play installation requires no F-Gas qualification. Rated Energy Class A+ (Tapping Profile L) under ErP Directive 812/2013, the NUOS Plus Wi-Fi 200D is CE-marked and EN 16147-verified.
This appliance must be installed by a competent person in compliance with BS 7671 (IET Wiring Regulations), local water byelaws, and the manufacturer's installation manual. A Type AB air break (tundish) and pressure/temperature relief valve are required on the DHW circuit. The unit is rated IPX4 — not suitable for direct outdoor exposure. A minimum room volume of 30 m³ is required for non-ducted operation. Do not install in the same room as an open-flued gas appliance.
The 200D is a direct model only — it has no secondary coil and cannot accept pre-heated water from a solar system or boiler. For indirect or solar-integrated installations, specify the 250I model. Minimum water hardness: 12°F; minimum conductivity: 150 µS/cm. In hard water areas above 25°F, fit a calibrated water softener maintaining residual hardness above 15°F.
The NUOS Plus Wi-Fi 200D includes a dedicated SG1/SG2 Smart Grid input that allows surplus solar PV energy to boost the tank beyond the normal set-point — using free generation that would otherwise be exported. The Photovoltaic function can switch between GREEN, STANDARD, HE or BOOST modes automatically when PV signal is detected, maximising self-consumption.
The rotary hermetic compressor extracts heat from ambient air and delivers it to the tank via a condenser coil wound directly around the tank shell, maximising heat transfer area without contact with domestic water. At 7°C ambient the unit achieves a COP of 3.10, rising to 3.35 at 42°C. The combination of heat pump + dual steatite immersion elements (1,500 W + 1,000 W) in BOOST mode achieves full reheat in under 4 hours — verified by independent EN 16147 test.
A Hot-Gas solenoid defrost valve routes high-pressure refrigerant directly through the evaporator to prevent ice build-up, allowing continuous heat pump operation from −10°C to +42°C ambient. Below −10°C the immersion element maintains tank temperature automatically. R134a refrigerant achieves water temperatures up to 62°C in heat pump mode — eliminating the need for an element to reach pasteurisation-range temperatures in most UK conditions.
The tank is protected by a sacrificial magnesium anode for broad-spectrum cathodic protection plus Ariston's proprietary ProTech active anode — an eddy-current device that generates a protective field without requiring periodic replacement. Both anodes are mounted on the same flange as the steatite elements, allowing access and replacement without draining the cylinder. The internal tank surface is coated with titanium-reinforced enamel fired at 850°C.
Seven selectable modes cover every usage scenario: GREEN (heat pump only), COMFORT (heat pump + element as required), FAST (permanent boost), BOOST (one-time rapid heat), PROGRAM (daily/weekly scheduling with up to 4 time slots per day), I-MEMORY (AI self-learning algorithm profiling usage over 4-week rolling average), and VOYAGE (standby during absence, auto-reactivation). The HC-HP mode activates heating only during low-tariff periods — ideal for Economy 7 or time-of-use tariffs.
An integrated Wi-Fi gateway connects directly to the free Aqua Ariston Net app (iOS/Android) for remote temperature setting, mode changes, scheduling and energy monitoring — no additional hardware required. The Bus BridgeNet connection enables full system integration with Ariston boilers and heat pumps via a Sensys HD controller, supporting single-app control of the entire heating and hot water system.
In Silent Mode the self-adaptive modulating fan reduces speed, limiting sound power to 51 dB(A) — equivalent to a domestic fridge-freezer. The air intake and exhaust connections accept Ø150, Ø160 or Ø200 mm ducts in multiple configurations (single or split exhaust/intake), with a maximum allowable pressure loss of 110 Pa. A standard air flow of 650 m³/h enables efficient operation even in partially-restricted spaces.
| Technical Specification — NUOS Plus Wi-Fi 200D (Code: 3820027) | |
|---|---|
| Storage & Tank | |
| Rated Storage Capacity | 200 litres |
| Tank Internal Coating | Titanium enamel, fired at 850°C |
| Corrosion Protection | Dual anode: sacrificial magnesium + ProTech active anode |
| Max. Operating Pressure (DHW) | 6 bar (0.6 MPa) |
| Hydraulic Connections | ¾" G male (cold inlet, hot outlet, recirculation) |
| Insulation | ≈50 mm polyurethane foam (CFC/HCFC-free) |
| Standing Heat Loss | 21 W (EN 16147) |
| Heat Pump Performance | |
| COP @ 7°C / 87% RH (EN 16147) | 3.10 |
| COP @ 42°C (peak performance) | 3.35 |
| Heat-Up Time (10°C → 55°C, 7°C ambient) | 3 hours 59 minutes |
| Max. Water Temp. (Heat Pump Mode) | 62°C |
| Max. Water Temp. (Immersion Element) | 75°C (factory set 65°C) |
| Average Electrical Power Consumption | 700 W |
| Max. Electrical Power Consumption | 900 W |
| Annual Energy Consumption (average climate) | 790 kWh/year |
| Max. Hot Water Yield @ 55°C | 256 litres (single intake, EN 16147) |
| Water Heating Efficiency (ηwh) | 130.0% (812/2013) |
| Energy Class / Tapping Profile | A+ / L |
| Refrigerant Circuit | |
| Refrigerant | R134a |
| Refrigerant Charge | 1.3 kg |
| GWP (R134a) | 1430 (1.859 t CO₂ eq.) |
| Max. Circuit Pressure (low side / high side) | 1.0 MPa / 2.7 MPa |
| Electrical Supply & Safety | |
| Voltage / Frequency | 220–240 V AC / 50 Hz |
| Heating Element Power | 1,500 W + 1,000 W (steatite dual-element) |
| Max. Total Power Consumption (all elements) | 2,500 W (see product label) |
| Max. Current Consumption | 11.48 A |
| Protection Rating | IPX4 |
| Recommended MCB | 16 A (fused connection unit) |
| Air Side & Installation | |
| Ambient Operating Range | −10°C to +42°C |
| Standard Air Flow (auto-modulating) | 650 m³/h |
| Available Static Pressure | 110 Pa (max. duct run per config.) |
| Duct Connection Diameters | Ø150 mm, Ø160 mm, Ø200 mm |
| Sound Power Level (standard / silent mode) | 55 dB(A) / 51 dB(A) |
| Minimum Room Volume (non-ducted) | 30 m³ |
| Min. Ceiling Height (non-ducted) | ≥ 1,940 mm |
| Condensate Drain Connection | Ø14 mm (siphon required) |
| Physical | |
| Dimensions (H × W × D) | 1,737 × 550 × 600 mm |
| Weight (empty / filled) | 90 kg / 290 kg |
Does the NUOS Plus 200D require an F-Gas certificate to install?
Can the 200D work without ducting in a utility room or garage?
What is I-Memory mode and how does it work?
How does the anti-legionella function work?
What is the difference between the 200D and the 250I model?
Can I integrate the NUOS Plus with my existing Ariston boiler?
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Description
The Ariston NUOS Plus Wi-Fi 200L Direct (NUOS200 / product code 3820027) is a floor-standing air source heat pump water heater that delivers up to 80% energy savings over a conventional direct cylinder. Its Coefficient of Performance (COP) of 3.10 at 7°C (EN 16147) means every 1 kWh of electricity generates the equivalent of 3.1 kWh of heat — absorbed from ambient air down to -10°C. The 200-litre titanium-enamelled steel tank reaches 55°C from cold in under 4 hours, one of the fastest heat-up times on the market. Built-in Wi-Fi via the Aqua Ariston Net app provides full remote control and scheduling, while Plug & Play installation requires no F-Gas qualification. Rated Energy Class A+ (Tapping Profile L) under ErP Directive 812/2013, the NUOS Plus Wi-Fi 200D is CE-marked and EN 16147-verified.
This appliance must be installed by a competent person in compliance with BS 7671 (IET Wiring Regulations), local water byelaws, and the manufacturer's installation manual. A Type AB air break (tundish) and pressure/temperature relief valve are required on the DHW circuit. The unit is rated IPX4 — not suitable for direct outdoor exposure. A minimum room volume of 30 m³ is required for non-ducted operation. Do not install in the same room as an open-flued gas appliance.
The 200D is a direct model only — it has no secondary coil and cannot accept pre-heated water from a solar system or boiler. For indirect or solar-integrated installations, specify the 250I model. Minimum water hardness: 12°F; minimum conductivity: 150 µS/cm. In hard water areas above 25°F, fit a calibrated water softener maintaining residual hardness above 15°F.
The NUOS Plus Wi-Fi 200D includes a dedicated SG1/SG2 Smart Grid input that allows surplus solar PV energy to boost the tank beyond the normal set-point — using free generation that would otherwise be exported. The Photovoltaic function can switch between GREEN, STANDARD, HE or BOOST modes automatically when PV signal is detected, maximising self-consumption.
The rotary hermetic compressor extracts heat from ambient air and delivers it to the tank via a condenser coil wound directly around the tank shell, maximising heat transfer area without contact with domestic water. At 7°C ambient the unit achieves a COP of 3.10, rising to 3.35 at 42°C. The combination of heat pump + dual steatite immersion elements (1,500 W + 1,000 W) in BOOST mode achieves full reheat in under 4 hours — verified by independent EN 16147 test.
A Hot-Gas solenoid defrost valve routes high-pressure refrigerant directly through the evaporator to prevent ice build-up, allowing continuous heat pump operation from −10°C to +42°C ambient. Below −10°C the immersion element maintains tank temperature automatically. R134a refrigerant achieves water temperatures up to 62°C in heat pump mode — eliminating the need for an element to reach pasteurisation-range temperatures in most UK conditions.
The tank is protected by a sacrificial magnesium anode for broad-spectrum cathodic protection plus Ariston's proprietary ProTech active anode — an eddy-current device that generates a protective field without requiring periodic replacement. Both anodes are mounted on the same flange as the steatite elements, allowing access and replacement without draining the cylinder. The internal tank surface is coated with titanium-reinforced enamel fired at 850°C.
Seven selectable modes cover every usage scenario: GREEN (heat pump only), COMFORT (heat pump + element as required), FAST (permanent boost), BOOST (one-time rapid heat), PROGRAM (daily/weekly scheduling with up to 4 time slots per day), I-MEMORY (AI self-learning algorithm profiling usage over 4-week rolling average), and VOYAGE (standby during absence, auto-reactivation). The HC-HP mode activates heating only during low-tariff periods — ideal for Economy 7 or time-of-use tariffs.
An integrated Wi-Fi gateway connects directly to the free Aqua Ariston Net app (iOS/Android) for remote temperature setting, mode changes, scheduling and energy monitoring — no additional hardware required. The Bus BridgeNet connection enables full system integration with Ariston boilers and heat pumps via a Sensys HD controller, supporting single-app control of the entire heating and hot water system.
In Silent Mode the self-adaptive modulating fan reduces speed, limiting sound power to 51 dB(A) — equivalent to a domestic fridge-freezer. The air intake and exhaust connections accept Ø150, Ø160 or Ø200 mm ducts in multiple configurations (single or split exhaust/intake), with a maximum allowable pressure loss of 110 Pa. A standard air flow of 650 m³/h enables efficient operation even in partially-restricted spaces.
| Technical Specification — NUOS Plus Wi-Fi 200D (Code: 3820027) | |
|---|---|
| Storage & Tank | |
| Rated Storage Capacity | 200 litres |
| Tank Internal Coating | Titanium enamel, fired at 850°C |
| Corrosion Protection | Dual anode: sacrificial magnesium + ProTech active anode |
| Max. Operating Pressure (DHW) | 6 bar (0.6 MPa) |
| Hydraulic Connections | ¾" G male (cold inlet, hot outlet, recirculation) |
| Insulation | ≈50 mm polyurethane foam (CFC/HCFC-free) |
| Standing Heat Loss | 21 W (EN 16147) |
| Heat Pump Performance | |
| COP @ 7°C / 87% RH (EN 16147) | 3.10 |
| COP @ 42°C (peak performance) | 3.35 |
| Heat-Up Time (10°C → 55°C, 7°C ambient) | 3 hours 59 minutes |
| Max. Water Temp. (Heat Pump Mode) | 62°C |
| Max. Water Temp. (Immersion Element) | 75°C (factory set 65°C) |
| Average Electrical Power Consumption | 700 W |
| Max. Electrical Power Consumption | 900 W |
| Annual Energy Consumption (average climate) | 790 kWh/year |
| Max. Hot Water Yield @ 55°C | 256 litres (single intake, EN 16147) |
| Water Heating Efficiency (ηwh) | 130.0% (812/2013) |
| Energy Class / Tapping Profile | A+ / L |
| Refrigerant Circuit | |
| Refrigerant | R134a |
| Refrigerant Charge | 1.3 kg |
| GWP (R134a) | 1430 (1.859 t CO₂ eq.) |
| Max. Circuit Pressure (low side / high side) | 1.0 MPa / 2.7 MPa |
| Electrical Supply & Safety | |
| Voltage / Frequency | 220–240 V AC / 50 Hz |
| Heating Element Power | 1,500 W + 1,000 W (steatite dual-element) |
| Max. Total Power Consumption (all elements) | 2,500 W (see product label) |
| Max. Current Consumption | 11.48 A |
| Protection Rating | IPX4 |
| Recommended MCB | 16 A (fused connection unit) |
| Air Side & Installation | |
| Ambient Operating Range | −10°C to +42°C |
| Standard Air Flow (auto-modulating) | 650 m³/h |
| Available Static Pressure | 110 Pa (max. duct run per config.) |
| Duct Connection Diameters | Ø150 mm, Ø160 mm, Ø200 mm |
| Sound Power Level (standard / silent mode) | 55 dB(A) / 51 dB(A) |
| Minimum Room Volume (non-ducted) | 30 m³ |
| Min. Ceiling Height (non-ducted) | ≥ 1,940 mm |
| Condensate Drain Connection | Ø14 mm (siphon required) |
| Physical | |
| Dimensions (H × W × D) | 1,737 × 550 × 600 mm |
| Weight (empty / filled) | 90 kg / 290 kg |
