Mixergy X Indirect Standard 550mm Unvented Cylinder | Boiler Smart Cylinder 150-300L | 2.0 Controller

Description

The Mixergy X Indirect Standard is a stainless steel unvented cylinder heated via an internal primary coil from a gas, oil or LPG boiler, with immersion backup and the 2.0 Controller for smart control. Every unit ships with WiFi connectivity and full compatibility with smart electricity tariffs for the immersion backup element.

The 550mm standard case spans 150 to 300 litres across five SKUs. Stratified thermocline sensing means the controller only heats the water volume actually needed, delivering minimum reheat times as fast as 11 minutes from the boiler coil.

150–300L

Capacity Range

550mm

Diameter

B/C

ErP Rating

18.3–23.6kW

Coil Rating

50mm

PU Foam Insulation

WiFi

App Connected

Please Note: Current Lead Times

Mixergy cylinders typically ship on a 3 to 6 week lead time, depending on model and quantity ordered. Please call us to check current availability before confirming an installation date.

Important: Unvented Installation Requirement

This is an unvented cylinder. Installation must be carried out by a G3-competent operative and commissioned per the manufacturer's Installation & Servicing instructions. Incoming mains pressure must be less than 10 bar and at least 1 bar, with a minimum flow rate of 10 L/min. Unvented cylinders must never be used with a solid fuel heat source.

Stratified Smart Charging

Thermocline sensors mean the controller only heats the volume of water required from the boiler coil, giving minimum reheat times as fast as 11 minutes.

Boiler-Fed with Immersion Backup

Heated primarily via the internal coil from a gas, oil or LPG boiler, with the 3kW immersion heater available as backup or for smart-tariff top-ups.

550mm Standard Case

The full-diameter case gives maximum capacity per unit height, suiting cylinder cupboards without width restrictions.

Full App Control & Monitoring

The bundled WiFi dongle connects to the Mixergy app for remote boost, live charge-state monitoring, and voice control via Google Assistant or Amazon Alexa.

High Coil Output

Coil ratings from 18.3kW to 23.6kW across the range support fast boiler-fed reheats even at the largest 300L capacity.

Safety-Certified Components

Factory-fitted monobloc cold water inlet control group, T&P relief valve (7 bar/90°C), and expansion vessel charged to 3 bar.

Controller & Electrical

Controller generation	2.0 Controller
Immersion heater rating	3kW, 230–240V~
Immersion heater specification	EN 60335-2-73, 356mm Incoloy
Electrical supply	16A, dedicated MCB-protected circuit
Thermostat safety cut-out	80°C
Adjustable temperature range (digital)	50–65°C
Connectivity	WiFi dongle (supplied) or hardwired Ethernet

Unvented Safety Components

Max. supply pressure to PRV	10 bar
Operating pressure	3 bar
Expansion vessel charge pressure	3 bar
Expansion relief valve setting	6 bar
T&P relief valve setting (pressure)	7 bar
T&P relief valve setting (temperature)	90°C
Coil max. working pressure	3.5 bar

Construction

Cylinder material	Stainless steel
Insulation type	CFC/HCFC-free polyurethane foam
Insulation thickness	50mm
Connection size/type	22mm compression
Coil max. working pressure	3.5 bar
Diverter valve (>70°C boilers)	Honeywell V4043H1056 2-port, or equivalent

Model Range

Model Code	Capacity	ErP	Height	Coil Rating	Weight Full	Min Reheat
MX-150-IND-550	150L	B	1117mm	18.3kW	178.2kg	11 mins
MX-180-IND-550	180L	B	1305mm	19.4kW	212.2kg	11 mins
MX-210-IND-550	210L	B	1493mm	19.9kW	245.2kg	12 mins
MX-250-IND-550	250L	C	1743mm	20.7kW	289.8kg	12 mins
MX-300-IND-550	300L	C	1989mm	23.6kW	344.6kg	12 mins

Please Note: Indirect Installations Over 70°C

Where the boiler or primary heat source is capable of exceeding 70°C, the supplied 2-port diverter valve (Honeywell V4043H1056 or equivalent) must be fitted, per the manufacturer's Installation & Servicing instructions.

What is the difference between Direct and Indirect models?

Indirect models heat water via an internal coil from a gas, oil or LPG boiler, with the immersion heater as backup. Direct models heat via immersion only.

Does the Mixergy X Indirect need an internet connection to work?

No — the cylinder heats and operates normally without WiFi. An internet connection unlocks app features such as remote control, smart tariff scheduling, and usage monitoring for the immersion backup.

Can the Mixergy X Indirect be used with a heat pump instead of a boiler?

Yes. The controller supports a heat pump heat source setting in place of a boiler, and cylinders have dedicated heat pump-ready ports. An optional plate heat exchanger is available.

What certification does the installer need?

Installation must be carried out by a competent operative who has completed a recognised unvented hot water systems course, with commissioning recorded per Building Regulations (G3) requirements.

What is included in the box?

Each cylinder ships with the monobloc cold water inlet control group, expansion vessel with mounting bracket, factory-fitted immersion heater(s), WiFi dongle, Ethernet cable, gauge, and user guide.

How long is the lead time and how do I check stock?

Lead times typically run 3 to 6 weeks depending on model and order quantity. Please call us to confirm current stock and expected delivery before booking an installation.

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