Instantaneous Inline
Thermostatic/ Non thermostatic
4.4 and 6.0 kW


Available in a thermostatic or non thermostatic model this instantaneous water heater is suitable for hand washing at a single basin. Confirm that the flow rate and temperature performance is adequate for your application using the chart and tables provided.

Click here to view our Instantaneous Key Points Card



• Supplies hot water to a single outlet
• Bare wire heating system gives fast heat up time
• Heats the water instantly as it flows through the unit
• Energy efficient – no standing heat losses
• 4.4 or 6.0 kW power rating
• Compact space saving design
• Intended for use with spray head taps with removable M22/ M24 nozzles
• Thermostatic models suitable to use with Vega infrared tap
• Not suitable for use with thermostatic mixing valves or taps or to supply a single lever mixer tap

Thermostatic Model Only
• External electronic thermostatic control accurate to the nearest degree
• Blue LED temperature display
• Energy saving – only uses the power required to deliver the chosen temperature
• Heating power adjusted electronically to compensate for temperature, flow rate and water pressure variations
• Temperature factory set at 38°C and can be adjusted by the user between 30°C and 48°C
• After power off/ on the unit will recall the last usage outlet temperature

Technical Specification

Outer Casing
Easy clean high impact ABS

Heating Element
Bare-wire heating system (3 nickel chrome heating elements)

Controls (Thermostatic Model only)
Temperature display (°C)

Power on/ off button

+/- controls allow the user to set the required temperature

The temperature display will flash if the set temperature cannot be reached.

Taps and Tap Spray Nozzles
Intended for use with spray head taps with removable M22/ M24 nozzles. Compatible tap available.

Important – the supplied tap spray nozzle must be fitted in the tap for best performance.

Overheat temperature protection 80°C.

Thermostatic model – water temperature controlled to maintain user selected temperature between 30°C and 48°C as water pressure conditions vary.

IP Rating

This appliance must be installed in a frost free environment.

The heater should be located as close as is practicable to the hot water outlet to avoid unnecessary heat losses through the pipework.

Must be installed by a suitably qualified person.

Minimum flow rate 2.0 l/m.
Minimum water pressure 1 bar.
Maximum rated pressure 7.5 bar.
Water resistivity ≥ 1300 Ωcm.

Water Connection
Inlet/Outlet 2 x 1/2" BSP male (40mm apart centre to centre).
Fittings required (not supplied): 2 x 15mm compression to 1/2" BSP female adapter.

Thermostatic model only is suitable for use with pre-heated water e.g. solar heating systems subject to maximum inlet water temperature 48°C.

Electrical Connection
Installation must comply with current IEE regulations.

Single phase. Fuse rating guide 19 amps for 4.4 kW and 26 amps for 6.0 kW.

The product should be connected to the fixed wiring of the property via a suitably rated isolating switch with contact separation of at least 3mm in all poles.

Cable pre-wired (0.7m).


Standard Warranty
1 year parts or replacement warranty.

Temperature Rise

Temperature rise from ambient for an instantaneous water heater (TR)

TR = kW rating x 14.3 / flow rate l/m


Recommended temperature for hand washing or shower 38°C.

Recommended temperature for a kitchen sink 50°C.

Ara, Rho and Aquila Instantaneous water heaters are intended for use with spray head taps with removable M22/ M24 nozzles. A tap spray nozzle must be fitted in the tap to control the water flow rate and to provide best performance and energy and water efficiency.

Selection Guide

Take into account that the incoming water supply temperature will be lower in the winter than summer.

The incoming water temperature can fluctuate dependent on time of year in the UK. Winter may result in incoming temperatures below 10°C, whereas summer water temperatures can be upwards of 15°C. It is imperative this is taken into account.

For example the heater could deliver 42°C water in the summer (with an incoming water supply temperature of 15°C). The same product with the same flow rate would only be able to deliver 37°C in winter (due to a lower incoming water temperature of 10°C). The delivered temperature will be even lower if the incoming water supply temperature is less than 10°C.

Check the flow rate and water temperature will be adequate for your application using the chart and tables provided below using each link.

Temperature Performance Charts

Click here for product performance with incoming water supply temperature of 17°C

Click here for product performance with incoming water supply temperature of 13°C

Click here for product performance with incoming water supply temperature of 10°C

Data Tables

Product CodePower (kW)ThermostaticMax Flow Rate (l/m) handwash *Standing Loss (kWh/day)
IN44 4.4No2.50.0

*Flow rates based on incoming water supply temperature of 13°C, hand wash at 38°C

Product CodeHeight (mm)Width (mm)Depth (mm)Weight Empyt (kg)
IN44, IN44T140190801.6
IN60, IN60T140190801.6
Product CodePower (kW)ApplicationWater Flow Rate for best performance (l/m)
IN44T4.4Hand washing at a single basin2.5
IN60T6.0Hand washing at a single basin2.5
IN96T9.6Hand washing at up to 2 basins or2 per basin
Light dishwashing or3 per sink
Light shower4 - 4.5
Maximum temperature increase from ambient incoming water supply temperature at a Flow Rate (l/m) ofIN44TIN60TIN96T

Energy Efficiency

The Energy Related Products (ErP) Directive and Energy Labelling Directive require that from September 2015 all water heaters in scope meet minimum energy performance criteria and have energy labels which provide the energy ration of the product. The classifications range from A++; this being the most efficient and coded in green to a rating of G; this being less efficient and coded in red.

Such ratings provide transparency of efficiency and a comparable benchmark for water heating products, as standardised European Energy Labels are used.

This website contains the energy class for all relevant water heating products. The full energy label and product fiche information for the Rho range can be found below.