ENGO E20i-W-UK Wireless Smart Thermostat – WiFi, Alexa & App Control, No Hub Required | White
ENGO E20i-W-UK Wireless Smart Thermostat – WiFi, Alexa & App Control, No Hub Required | White
WiFi — No Hub Required 868 MHz RF Wireless Works Offline Alexa & Google UK Model — Batteries Included
The ENGO E20i-W-UK Wireless Smart Thermostat in White is a hub-free Wi-Fi thermostat designed for straightforward intelligent heating control of combi boilers, system boilers, zone valves, and wiring centres. The battery-powered thermostat head communicates wirelessly to a mains-wired receiver — which contains the built-in Wi-Fi module — giving you full remote control via the ENGO Smart app, Amazon Alexa, or Google Assistant, without the need for a separate internet gateway. Ships factory-paired, batteries included, and ready to install.
Unlike many smart thermostats that require a dedicated hub or bridge, the E20i-W-UK keeps things genuinely simple: the receiver connects to your home Wi-Fi directly, and the thermostat head sits wherever it reads room temperature best — on a wall, shelf, or worktop via the included desk stand. The clean white finish blends seamlessly with standard UK walls, sockets, and light switches, making it the most discreet option for a traditional or neutral interior.
Why Buy the ENGO E20i-W-UK?
Suitable For
Product Description
The ENGO E20i-W-UK is a two-part system: a compact battery-powered thermostat head (80 × 80 × 23 mm) and a mains-powered receiver (96 × 96 × 27 mm) that wires directly to the heating system. The receiver contains the Wi-Fi chip — connecting to your 2.4 GHz network and acting as the bridge between the ENGO Smart app and the thermostat — meaning no separate hub is required and there are no extra devices cluttering your boiler cupboard.
The thermostat head and receiver communicate via a dedicated 868 MHz RF link — a frequency less prone to interference than 2.4 GHz, giving reliable wireless performance through walls and across floors. Each device uses unique transmission codes, preventing signal crosstalk with neighbouring ENGO systems in flats or terraced properties.
📱 ENGO Smart App — Full Control From Anywhere
Download the free ENGO Smart app (iOS & Android) for the complete feature set:
- Remote temperature adjustment from anywhere with an internet connection
- 7-day programmable weekly schedule with multiple daily periods
- Manual override — boost heating or switch off from your phone instantly
- Share access with family members, a letting agent, or a property manager
- Monitor real-time room temperature and current setpoint
- Compatible with Alexa, Google Assistant, SmartLife, and Tuya Smart (Tuya Cloud platform)
✅ Works Without an Internet Connection
If your broadband drops, the E20i-W-UK continues to operate normally in offline mode — maintaining the last schedule or setpoint locally. Your heating won't turn off just because your internet is down. This makes it a reliable choice for rural properties, holiday homes, or any installation where connectivity can be intermittent.
The TPI (Time Proportional and Integral) control algorithm modulates the heating output based on the gap between the current room temperature and the setpoint — cycling the boiler more frequently when the gap is small, and less so when it's large. This produces more stable room temperatures with less overshoot, and is particularly well-suited to underfloor heating systems where slow thermal response can cause conventional on/off thermostats to hunt. Standard hysteresis (on/off) control is also selectable via the installer settings (±0.2°C to ±2°C dead band) if preferred for simpler radiator systems.
The receiver output is a volt-free (dry contact) COM/NO — compatible with virtually any heating system that accepts a room thermostat signal: combi boilers, system boilers, oil and LPG boilers, zone valves, fan coil units, and wet underfloor heating manifold pump circuits. The receiver is rated at 16(5)A, sufficient for direct connection to most standard UK heating loads.
Temperature is adjustable between 5°C and 35°C in 0.5°C steps. Minimum and maximum setpoint limits are configurable via the installer settings — useful for holiday lets or landlord-managed properties where you want to cap how far the heating can be adjusted. The large, legible backlit display shows current room temperature and target setpoint simultaneously.
Key Features
- Wi-Fi built into the receiver — no hub, bridge, or gateway required
- 868 MHz RF link between thermostat and receiver — reliable, long-range wireless
- Factory pre-paired — thermostat and receiver ready to use from the box
- 2 × AA batteries included (UK model)
- ENGO Smart app control (iOS & Android) — Tuya Cloud platform
- Amazon Alexa, Google Assistant, SmartLife & Tuya Smart compatible
- Offline operation — maintains last schedule/setpoint without internet connection
- 7-day programmable schedule with multiple periods per day
- TPI algorithm — or switchable to hysteresis (±0.2°C to ±2°C) via installer settings
- Heating / Cooling mode — switchable output for heat pump and fan coil compatibility
- PIN / child lock at the thermostat head
- Configurable min/max setpoint limits — ideal for rental properties
- Temperature range: 5°C – 35°C (0.5°C display accuracy)
- Unique transmission codes — prevents interference with neighbouring systems
- Thermostat: 2 × AA batteries — no wiring required at thermostat position
- Receiver: 230V AC / 50Hz — volt-free COM/NO output, 16(5)A rated
- Wall-mount or desk stand — desk stand included
- White finish — black version available: E20i-B-UK
- UK & EU certified — compliant with UK regulations and EU Directives 2014/53/EU & 2016/65/EU
Technical Specifications
| Specification | Detail |
|---|---|
| Model (UK) | E20i-W-UK — White |
| Thermostat Power Supply | 2 × AA batteries (included) |
| Receiver Power Supply | 230V AC / 50Hz |
| Receiver Max Load | 16(5)A |
| Receiver Output | Volt-free COM / NO (dry contact) |
| Temperature Control Range | 5.0°C – 35.0°C |
| Display Temperature Accuracy | 0.5°C |
| Control Algorithm | TPI — or Hysteresis (±0.2°C to ±2°C), selectable via installer settings |
| RF Communication (thermostat ↔ receiver) | 868 MHz (unique transmission codes) |
| RF Frequency Band | 868.0–868.6 MHz (<13 dBm) |
| Wi-Fi Communication (receiver ↔ router) | 2.4 GHz Wi-Fi — 5 GHz not supported |
| Hub / Gateway Required | No — Wi-Fi module built into receiver |
| App Platform | ENGO Smart (Tuya Cloud) — iOS & Android |
| Voice Assistants | Amazon Alexa, Google Assistant |
| Smart Home Platforms | SmartLife, Tuya Smart |
| OpenTherm Compatible | No — volt-free on/off output only |
| Offline Operation | Yes — maintains last schedule/setpoint without internet |
| Heating / Cooling Mode | Yes — switchable via installer settings |
| Weekly Schedule | 7-day programmable via app |
| PIN / Child Lock | Yes |
| Min/Max Setpoint Limit | Configurable via installer settings |
| Thermostat Dimensions | 80 × 80 × 23 mm |
| Receiver Dimensions | 96 × 96 × 27 mm |
| Colour | White |
| Mounting Options | Wall-mount or desk stand (desk stand included) |
| Certification | UK & EU certified — 2014/53/EU, 2016/65/EU |
Installation & Compatibility Notes
The receiver wires to the heating system using standard room thermostat wiring (L, N, Earth, and the switched COM/NO output). It is compatible with any heating appliance that accepts a volt-free (dry contact) room thermostat signal — including gas, oil, and LPG combi and system boilers, electric boilers, motorised zone valves, wiring centres, and wet underfloor heating pump/actuator circuits. The receiver's volt-free output means it is safe for use with low-voltage control systems as well as mains-voltage switching within the 16(5)A rating.
OpenTherm: The E20i-W-UK uses a standard on/off volt-free output only — it does not support OpenTherm modulating communication. It will still control an OpenTherm-compatible boiler, but only in simple on/off mode rather than modulating mode.
The thermostat head is battery-powered (2 × AA batteries included) and requires no wiring — position it freely on a wall or use the desk stand. Mount away from direct sunlight, draughts, external walls, and heat sources for the most accurate temperature reading. The 868 MHz RF link gives reliable through-wall range; for very large properties or thick stone walls, test signal strength before committing to a fixed position.
Wi-Fi setup requires a 2.4 GHz network only — the receiver does not connect to 5 GHz. If your router broadcasts a combined 2.4/5 GHz network under one SSID, temporarily separate the bands (or connect your phone to 2.4 GHz) during initial setup. All wiring of the receiver must be carried out by a competent person in accordance with BS 7671 (IET Wiring Regulations) and the heating appliance manufacturer's instructions.
Frequently Asked Questions
Do I need a separate hub or bridge?
No. The Wi-Fi module is built directly into the receiver unit. All you need is a standard 2.4 GHz home Wi-Fi network — no ENGO gateway, bridge, or any additional hardware is required.
Are batteries included?
Yes — the UK model (E20i-W-UK) ships with 2 × AA batteries for the thermostat head.
Does it work with OpenTherm boilers?
No — the E20i-W-UK uses a volt-free on/off output only and does not support OpenTherm modulating communication. It will control an OpenTherm boiler, but only in simple on/off mode, not modulating mode.
What happens if my internet goes down?
The thermostat continues to function normally in offline mode, maintaining its last setpoint or schedule locally. Your heating will not switch off due to a broadband outage.
Can multiple people control it from the app?
Yes — the thermostat can be shared with multiple users via the ENGO Smart app, so all household members or a property manager can access and adjust it from their own devices.
My router uses a combined 2.4/5 GHz network — will it still work?
The receiver only supports 2.4 GHz. If your router uses a single SSID for both bands, you may need to temporarily separate them (or connect your phone to the 2.4 GHz band) during initial Wi-Fi setup. Once connected, the thermostat will work normally.
What is TPI control and do I need it?
TPI (Time Proportional and Integral) modulates the boiler's duty cycle based on how far the room is from the target temperature, producing more stable, efficient heating than simple on/off switching. It is particularly beneficial for underfloor heating systems with slow thermal response. Standard hysteresis mode (±0.2°C to ±2°C dead band) is also available via installer settings if preferred for a straightforward radiator system.
Can it be used in a rental property?
Yes — the desk stand means the thermostat head doesn't need to be permanently wall-mounted. The receiver requires permanent wiring to the boiler (a one-time installation). Once installed, access can be shared with tenants, and the configurable min/max setpoint limits let landlords cap how far the temperature can be adjusted.
Is there a black version?
Yes — the ENGO E20i-B-UK (black) is identical in specification and features. The only difference is the colour of the thermostat head and receiver fascia.
What's in the Box
- ENGO E20i-W-UK thermostat head (white) — pre-paired to receiver
- E20i receiver / Wi-Fi module — for wiring to heating system
- 2 × AA batteries (for thermostat head)
- Desk stand for thermostat head
- Wall-mounting screws and fixings for both units
- Quick start guide (multilingual, English included)
Original: $103.92
-65%$103.92
$36.37More Images
ENGO E20i-W-UK Wireless Smart Thermostat – WiFi, Alexa & App Control, No Hub Required | White
WiFi — No Hub Required 868 MHz RF Wireless Works Offline Alexa & Google UK Model — Batteries Included
The ENGO E20i-W-UK Wireless Smart Thermostat in White is a hub-free Wi-Fi thermostat designed for straightforward intelligent heating control of combi boilers, system boilers, zone valves, and wiring centres. The battery-powered thermostat head communicates wirelessly to a mains-wired receiver — which contains the built-in Wi-Fi module — giving you full remote control via the ENGO Smart app, Amazon Alexa, or Google Assistant, without the need for a separate internet gateway. Ships factory-paired, batteries included, and ready to install.
Unlike many smart thermostats that require a dedicated hub or bridge, the E20i-W-UK keeps things genuinely simple: the receiver connects to your home Wi-Fi directly, and the thermostat head sits wherever it reads room temperature best — on a wall, shelf, or worktop via the included desk stand. The clean white finish blends seamlessly with standard UK walls, sockets, and light switches, making it the most discreet option for a traditional or neutral interior.
Why Buy the ENGO E20i-W-UK?
Suitable For
Product Description
The ENGO E20i-W-UK is a two-part system: a compact battery-powered thermostat head (80 × 80 × 23 mm) and a mains-powered receiver (96 × 96 × 27 mm) that wires directly to the heating system. The receiver contains the Wi-Fi chip — connecting to your 2.4 GHz network and acting as the bridge between the ENGO Smart app and the thermostat — meaning no separate hub is required and there are no extra devices cluttering your boiler cupboard.
The thermostat head and receiver communicate via a dedicated 868 MHz RF link — a frequency less prone to interference than 2.4 GHz, giving reliable wireless performance through walls and across floors. Each device uses unique transmission codes, preventing signal crosstalk with neighbouring ENGO systems in flats or terraced properties.
📱 ENGO Smart App — Full Control From Anywhere
Download the free ENGO Smart app (iOS & Android) for the complete feature set:
- Remote temperature adjustment from anywhere with an internet connection
- 7-day programmable weekly schedule with multiple daily periods
- Manual override — boost heating or switch off from your phone instantly
- Share access with family members, a letting agent, or a property manager
- Monitor real-time room temperature and current setpoint
- Compatible with Alexa, Google Assistant, SmartLife, and Tuya Smart (Tuya Cloud platform)
✅ Works Without an Internet Connection
If your broadband drops, the E20i-W-UK continues to operate normally in offline mode — maintaining the last schedule or setpoint locally. Your heating won't turn off just because your internet is down. This makes it a reliable choice for rural properties, holiday homes, or any installation where connectivity can be intermittent.
The TPI (Time Proportional and Integral) control algorithm modulates the heating output based on the gap between the current room temperature and the setpoint — cycling the boiler more frequently when the gap is small, and less so when it's large. This produces more stable room temperatures with less overshoot, and is particularly well-suited to underfloor heating systems where slow thermal response can cause conventional on/off thermostats to hunt. Standard hysteresis (on/off) control is also selectable via the installer settings (±0.2°C to ±2°C dead band) if preferred for simpler radiator systems.
The receiver output is a volt-free (dry contact) COM/NO — compatible with virtually any heating system that accepts a room thermostat signal: combi boilers, system boilers, oil and LPG boilers, zone valves, fan coil units, and wet underfloor heating manifold pump circuits. The receiver is rated at 16(5)A, sufficient for direct connection to most standard UK heating loads.
Temperature is adjustable between 5°C and 35°C in 0.5°C steps. Minimum and maximum setpoint limits are configurable via the installer settings — useful for holiday lets or landlord-managed properties where you want to cap how far the heating can be adjusted. The large, legible backlit display shows current room temperature and target setpoint simultaneously.
Key Features
- Wi-Fi built into the receiver — no hub, bridge, or gateway required
- 868 MHz RF link between thermostat and receiver — reliable, long-range wireless
- Factory pre-paired — thermostat and receiver ready to use from the box
- 2 × AA batteries included (UK model)
- ENGO Smart app control (iOS & Android) — Tuya Cloud platform
- Amazon Alexa, Google Assistant, SmartLife & Tuya Smart compatible
- Offline operation — maintains last schedule/setpoint without internet connection
- 7-day programmable schedule with multiple periods per day
- TPI algorithm — or switchable to hysteresis (±0.2°C to ±2°C) via installer settings
- Heating / Cooling mode — switchable output for heat pump and fan coil compatibility
- PIN / child lock at the thermostat head
- Configurable min/max setpoint limits — ideal for rental properties
- Temperature range: 5°C – 35°C (0.5°C display accuracy)
- Unique transmission codes — prevents interference with neighbouring systems
- Thermostat: 2 × AA batteries — no wiring required at thermostat position
- Receiver: 230V AC / 50Hz — volt-free COM/NO output, 16(5)A rated
- Wall-mount or desk stand — desk stand included
- White finish — black version available: E20i-B-UK
- UK & EU certified — compliant with UK regulations and EU Directives 2014/53/EU & 2016/65/EU
Technical Specifications
| Specification | Detail |
|---|---|
| Model (UK) | E20i-W-UK — White |
| Thermostat Power Supply | 2 × AA batteries (included) |
| Receiver Power Supply | 230V AC / 50Hz |
| Receiver Max Load | 16(5)A |
| Receiver Output | Volt-free COM / NO (dry contact) |
| Temperature Control Range | 5.0°C – 35.0°C |
| Display Temperature Accuracy | 0.5°C |
| Control Algorithm | TPI — or Hysteresis (±0.2°C to ±2°C), selectable via installer settings |
| RF Communication (thermostat ↔ receiver) | 868 MHz (unique transmission codes) |
| RF Frequency Band | 868.0–868.6 MHz (<13 dBm) |
| Wi-Fi Communication (receiver ↔ router) | 2.4 GHz Wi-Fi — 5 GHz not supported |
| Hub / Gateway Required | No — Wi-Fi module built into receiver |
| App Platform | ENGO Smart (Tuya Cloud) — iOS & Android |
| Voice Assistants | Amazon Alexa, Google Assistant |
| Smart Home Platforms | SmartLife, Tuya Smart |
| OpenTherm Compatible | No — volt-free on/off output only |
| Offline Operation | Yes — maintains last schedule/setpoint without internet |
| Heating / Cooling Mode | Yes — switchable via installer settings |
| Weekly Schedule | 7-day programmable via app |
| PIN / Child Lock | Yes |
| Min/Max Setpoint Limit | Configurable via installer settings |
| Thermostat Dimensions | 80 × 80 × 23 mm |
| Receiver Dimensions | 96 × 96 × 27 mm |
| Colour | White |
| Mounting Options | Wall-mount or desk stand (desk stand included) |
| Certification | UK & EU certified — 2014/53/EU, 2016/65/EU |
Installation & Compatibility Notes
The receiver wires to the heating system using standard room thermostat wiring (L, N, Earth, and the switched COM/NO output). It is compatible with any heating appliance that accepts a volt-free (dry contact) room thermostat signal — including gas, oil, and LPG combi and system boilers, electric boilers, motorised zone valves, wiring centres, and wet underfloor heating pump/actuator circuits. The receiver's volt-free output means it is safe for use with low-voltage control systems as well as mains-voltage switching within the 16(5)A rating.
OpenTherm: The E20i-W-UK uses a standard on/off volt-free output only — it does not support OpenTherm modulating communication. It will still control an OpenTherm-compatible boiler, but only in simple on/off mode rather than modulating mode.
The thermostat head is battery-powered (2 × AA batteries included) and requires no wiring — position it freely on a wall or use the desk stand. Mount away from direct sunlight, draughts, external walls, and heat sources for the most accurate temperature reading. The 868 MHz RF link gives reliable through-wall range; for very large properties or thick stone walls, test signal strength before committing to a fixed position.
Wi-Fi setup requires a 2.4 GHz network only — the receiver does not connect to 5 GHz. If your router broadcasts a combined 2.4/5 GHz network under one SSID, temporarily separate the bands (or connect your phone to 2.4 GHz) during initial setup. All wiring of the receiver must be carried out by a competent person in accordance with BS 7671 (IET Wiring Regulations) and the heating appliance manufacturer's instructions.
Frequently Asked Questions
Do I need a separate hub or bridge?
No. The Wi-Fi module is built directly into the receiver unit. All you need is a standard 2.4 GHz home Wi-Fi network — no ENGO gateway, bridge, or any additional hardware is required.
Are batteries included?
Yes — the UK model (E20i-W-UK) ships with 2 × AA batteries for the thermostat head.
Does it work with OpenTherm boilers?
No — the E20i-W-UK uses a volt-free on/off output only and does not support OpenTherm modulating communication. It will control an OpenTherm boiler, but only in simple on/off mode, not modulating mode.
What happens if my internet goes down?
The thermostat continues to function normally in offline mode, maintaining its last setpoint or schedule locally. Your heating will not switch off due to a broadband outage.
Can multiple people control it from the app?
Yes — the thermostat can be shared with multiple users via the ENGO Smart app, so all household members or a property manager can access and adjust it from their own devices.
My router uses a combined 2.4/5 GHz network — will it still work?
The receiver only supports 2.4 GHz. If your router uses a single SSID for both bands, you may need to temporarily separate them (or connect your phone to the 2.4 GHz band) during initial Wi-Fi setup. Once connected, the thermostat will work normally.
What is TPI control and do I need it?
TPI (Time Proportional and Integral) modulates the boiler's duty cycle based on how far the room is from the target temperature, producing more stable, efficient heating than simple on/off switching. It is particularly beneficial for underfloor heating systems with slow thermal response. Standard hysteresis mode (±0.2°C to ±2°C dead band) is also available via installer settings if preferred for a straightforward radiator system.
Can it be used in a rental property?
Yes — the desk stand means the thermostat head doesn't need to be permanently wall-mounted. The receiver requires permanent wiring to the boiler (a one-time installation). Once installed, access can be shared with tenants, and the configurable min/max setpoint limits let landlords cap how far the temperature can be adjusted.
Is there a black version?
Yes — the ENGO E20i-B-UK (black) is identical in specification and features. The only difference is the colour of the thermostat head and receiver fascia.
What's in the Box
- ENGO E20i-W-UK thermostat head (white) — pre-paired to receiver
- E20i receiver / Wi-Fi module — for wiring to heating system
- 2 × AA batteries (for thermostat head)
- Desk stand for thermostat head
- Wall-mounting screws and fixings for both units
- Quick start guide (multilingual, English included)
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
WiFi — No Hub Required 868 MHz RF Wireless Works Offline Alexa & Google UK Model — Batteries Included
The ENGO E20i-W-UK Wireless Smart Thermostat in White is a hub-free Wi-Fi thermostat designed for straightforward intelligent heating control of combi boilers, system boilers, zone valves, and wiring centres. The battery-powered thermostat head communicates wirelessly to a mains-wired receiver — which contains the built-in Wi-Fi module — giving you full remote control via the ENGO Smart app, Amazon Alexa, or Google Assistant, without the need for a separate internet gateway. Ships factory-paired, batteries included, and ready to install.
Unlike many smart thermostats that require a dedicated hub or bridge, the E20i-W-UK keeps things genuinely simple: the receiver connects to your home Wi-Fi directly, and the thermostat head sits wherever it reads room temperature best — on a wall, shelf, or worktop via the included desk stand. The clean white finish blends seamlessly with standard UK walls, sockets, and light switches, making it the most discreet option for a traditional or neutral interior.
Why Buy the ENGO E20i-W-UK?
Suitable For
Product Description
The ENGO E20i-W-UK is a two-part system: a compact battery-powered thermostat head (80 × 80 × 23 mm) and a mains-powered receiver (96 × 96 × 27 mm) that wires directly to the heating system. The receiver contains the Wi-Fi chip — connecting to your 2.4 GHz network and acting as the bridge between the ENGO Smart app and the thermostat — meaning no separate hub is required and there are no extra devices cluttering your boiler cupboard.
The thermostat head and receiver communicate via a dedicated 868 MHz RF link — a frequency less prone to interference than 2.4 GHz, giving reliable wireless performance through walls and across floors. Each device uses unique transmission codes, preventing signal crosstalk with neighbouring ENGO systems in flats or terraced properties.
📱 ENGO Smart App — Full Control From Anywhere
Download the free ENGO Smart app (iOS & Android) for the complete feature set:
- Remote temperature adjustment from anywhere with an internet connection
- 7-day programmable weekly schedule with multiple daily periods
- Manual override — boost heating or switch off from your phone instantly
- Share access with family members, a letting agent, or a property manager
- Monitor real-time room temperature and current setpoint
- Compatible with Alexa, Google Assistant, SmartLife, and Tuya Smart (Tuya Cloud platform)
✅ Works Without an Internet Connection
If your broadband drops, the E20i-W-UK continues to operate normally in offline mode — maintaining the last schedule or setpoint locally. Your heating won't turn off just because your internet is down. This makes it a reliable choice for rural properties, holiday homes, or any installation where connectivity can be intermittent.
The TPI (Time Proportional and Integral) control algorithm modulates the heating output based on the gap between the current room temperature and the setpoint — cycling the boiler more frequently when the gap is small, and less so when it's large. This produces more stable room temperatures with less overshoot, and is particularly well-suited to underfloor heating systems where slow thermal response can cause conventional on/off thermostats to hunt. Standard hysteresis (on/off) control is also selectable via the installer settings (±0.2°C to ±2°C dead band) if preferred for simpler radiator systems.
The receiver output is a volt-free (dry contact) COM/NO — compatible with virtually any heating system that accepts a room thermostat signal: combi boilers, system boilers, oil and LPG boilers, zone valves, fan coil units, and wet underfloor heating manifold pump circuits. The receiver is rated at 16(5)A, sufficient for direct connection to most standard UK heating loads.
Temperature is adjustable between 5°C and 35°C in 0.5°C steps. Minimum and maximum setpoint limits are configurable via the installer settings — useful for holiday lets or landlord-managed properties where you want to cap how far the heating can be adjusted. The large, legible backlit display shows current room temperature and target setpoint simultaneously.
Key Features
- Wi-Fi built into the receiver — no hub, bridge, or gateway required
- 868 MHz RF link between thermostat and receiver — reliable, long-range wireless
- Factory pre-paired — thermostat and receiver ready to use from the box
- 2 × AA batteries included (UK model)
- ENGO Smart app control (iOS & Android) — Tuya Cloud platform
- Amazon Alexa, Google Assistant, SmartLife & Tuya Smart compatible
- Offline operation — maintains last schedule/setpoint without internet connection
- 7-day programmable schedule with multiple periods per day
- TPI algorithm — or switchable to hysteresis (±0.2°C to ±2°C) via installer settings
- Heating / Cooling mode — switchable output for heat pump and fan coil compatibility
- PIN / child lock at the thermostat head
- Configurable min/max setpoint limits — ideal for rental properties
- Temperature range: 5°C – 35°C (0.5°C display accuracy)
- Unique transmission codes — prevents interference with neighbouring systems
- Thermostat: 2 × AA batteries — no wiring required at thermostat position
- Receiver: 230V AC / 50Hz — volt-free COM/NO output, 16(5)A rated
- Wall-mount or desk stand — desk stand included
- White finish — black version available: E20i-B-UK
- UK & EU certified — compliant with UK regulations and EU Directives 2014/53/EU & 2016/65/EU
Technical Specifications
| Specification | Detail |
|---|---|
| Model (UK) | E20i-W-UK — White |
| Thermostat Power Supply | 2 × AA batteries (included) |
| Receiver Power Supply | 230V AC / 50Hz |
| Receiver Max Load | 16(5)A |
| Receiver Output | Volt-free COM / NO (dry contact) |
| Temperature Control Range | 5.0°C – 35.0°C |
| Display Temperature Accuracy | 0.5°C |
| Control Algorithm | TPI — or Hysteresis (±0.2°C to ±2°C), selectable via installer settings |
| RF Communication (thermostat ↔ receiver) | 868 MHz (unique transmission codes) |
| RF Frequency Band | 868.0–868.6 MHz (<13 dBm) |
| Wi-Fi Communication (receiver ↔ router) | 2.4 GHz Wi-Fi — 5 GHz not supported |
| Hub / Gateway Required | No — Wi-Fi module built into receiver |
| App Platform | ENGO Smart (Tuya Cloud) — iOS & Android |
| Voice Assistants | Amazon Alexa, Google Assistant |
| Smart Home Platforms | SmartLife, Tuya Smart |
| OpenTherm Compatible | No — volt-free on/off output only |
| Offline Operation | Yes — maintains last schedule/setpoint without internet |
| Heating / Cooling Mode | Yes — switchable via installer settings |
| Weekly Schedule | 7-day programmable via app |
| PIN / Child Lock | Yes |
| Min/Max Setpoint Limit | Configurable via installer settings |
| Thermostat Dimensions | 80 × 80 × 23 mm |
| Receiver Dimensions | 96 × 96 × 27 mm |
| Colour | White |
| Mounting Options | Wall-mount or desk stand (desk stand included) |
| Certification | UK & EU certified — 2014/53/EU, 2016/65/EU |
Installation & Compatibility Notes
The receiver wires to the heating system using standard room thermostat wiring (L, N, Earth, and the switched COM/NO output). It is compatible with any heating appliance that accepts a volt-free (dry contact) room thermostat signal — including gas, oil, and LPG combi and system boilers, electric boilers, motorised zone valves, wiring centres, and wet underfloor heating pump/actuator circuits. The receiver's volt-free output means it is safe for use with low-voltage control systems as well as mains-voltage switching within the 16(5)A rating.
OpenTherm: The E20i-W-UK uses a standard on/off volt-free output only — it does not support OpenTherm modulating communication. It will still control an OpenTherm-compatible boiler, but only in simple on/off mode rather than modulating mode.
The thermostat head is battery-powered (2 × AA batteries included) and requires no wiring — position it freely on a wall or use the desk stand. Mount away from direct sunlight, draughts, external walls, and heat sources for the most accurate temperature reading. The 868 MHz RF link gives reliable through-wall range; for very large properties or thick stone walls, test signal strength before committing to a fixed position.
Wi-Fi setup requires a 2.4 GHz network only — the receiver does not connect to 5 GHz. If your router broadcasts a combined 2.4/5 GHz network under one SSID, temporarily separate the bands (or connect your phone to 2.4 GHz) during initial setup. All wiring of the receiver must be carried out by a competent person in accordance with BS 7671 (IET Wiring Regulations) and the heating appliance manufacturer's instructions.
Frequently Asked Questions
Do I need a separate hub or bridge?
No. The Wi-Fi module is built directly into the receiver unit. All you need is a standard 2.4 GHz home Wi-Fi network — no ENGO gateway, bridge, or any additional hardware is required.
Are batteries included?
Yes — the UK model (E20i-W-UK) ships with 2 × AA batteries for the thermostat head.
Does it work with OpenTherm boilers?
No — the E20i-W-UK uses a volt-free on/off output only and does not support OpenTherm modulating communication. It will control an OpenTherm boiler, but only in simple on/off mode, not modulating mode.
What happens if my internet goes down?
The thermostat continues to function normally in offline mode, maintaining its last setpoint or schedule locally. Your heating will not switch off due to a broadband outage.
Can multiple people control it from the app?
Yes — the thermostat can be shared with multiple users via the ENGO Smart app, so all household members or a property manager can access and adjust it from their own devices.
My router uses a combined 2.4/5 GHz network — will it still work?
The receiver only supports 2.4 GHz. If your router uses a single SSID for both bands, you may need to temporarily separate them (or connect your phone to the 2.4 GHz band) during initial Wi-Fi setup. Once connected, the thermostat will work normally.
What is TPI control and do I need it?
TPI (Time Proportional and Integral) modulates the boiler's duty cycle based on how far the room is from the target temperature, producing more stable, efficient heating than simple on/off switching. It is particularly beneficial for underfloor heating systems with slow thermal response. Standard hysteresis mode (±0.2°C to ±2°C dead band) is also available via installer settings if preferred for a straightforward radiator system.
Can it be used in a rental property?
Yes — the desk stand means the thermostat head doesn't need to be permanently wall-mounted. The receiver requires permanent wiring to the boiler (a one-time installation). Once installed, access can be shared with tenants, and the configurable min/max setpoint limits let landlords cap how far the temperature can be adjusted.
Is there a black version?
Yes — the ENGO E20i-B-UK (black) is identical in specification and features. The only difference is the colour of the thermostat head and receiver fascia.
What's in the Box
- ENGO E20i-W-UK thermostat head (white) — pre-paired to receiver
- E20i receiver / Wi-Fi module — for wiring to heating system
- 2 × AA batteries (for thermostat head)
- Desk stand for thermostat head
- Wall-mounting screws and fixings for both units
- Quick start guide (multilingual, English included)
