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OUH3 Industrial Fan Heater

System X
  • Provides an efficient means of heating industrial premises
  • Typical applications include warehouses and workshops
  • The most robust unit heater available offering exceptional reliability and backed by a 5 YEAR WARRANTY
  • Choice of seven models from 3kW to 40kW all with built in thermostat
  • Up to 16 various heaters can be operated by a single controller 
  • OUH3-03 to 25 includes specially designed bracket for wall or ceiling mounting (heaters also suitable for suspension mounting)
  • OUH3-40 includes brackets for drop rod mounting

Range & Prices

The prices shown are list prices and perfectly safe to use for budget purposes. Contact your electrical wholesaler for final prices.

10kW heater providing background heat in a storage facility in Kent

BN Thermic industrial fan heaters are manufactured and hand assembled in the UK. Backed with a 5 year warranty 

Model Number kW Voltage List Price
OUH3-03 3 230V £1186.00
OUH3-06 6 230V £1239.00
OUH3-09 9 230V or 400V/3N £1326.00
OUH3-15 15 400V/3N £1834.00
OUH3-20 20 400V/3N £1968.00
OUH3-25 25 400V/3N £1999.00
OUH3-40 40 400V/3N £2998.00

Controls / Accessories

Each OUH3 industrial fan heater has a built-in mechanical thermostat as standard. For additional control, see options below. 


Add an OUH3-S switch for easy on/off control (without the need to access the mechanical thermostat) and to select ‘fan only’ mode (summer use).


Add a frost thermostat for reliable frost protection irrespective of settings on the mechanical thermostat or the OUH2-S switch.

OUH3s can be controlled electronically via a 7-day programmable thermostat or remotely from a phone via a Wi-Fi thermostat. See below. 

Model Description List Price
OUH3-S OUH3-S Switch (on/off/fan only) £79.00
programmable thermostat RT16 Electronic programmable thermostat 16A £144.00
OUH3-DT OUH3-DT Electronic programable thermostat + Control switch (on/off/fan only) £154.00
OUH3-WiFi OUH3-WiFi WiFi programable thermostat + Control switch (on/off/fan only) free app £211.00
CXS 01 CXS Optional remote air sensor for RT16 or OUH3-DT £42.00
PROTIM 7_04 PROTIM-7 Programable Timer £182.00
FST-RS FST-RS Frost Protection Tamperproof Thermostat. Overrides all other controls and OUH3-S switch £138.00
RST-RS RST-RS Tamperproof Thermostat – Rough Service £143.00
PROSTAT2-1a PROSTAT-2 Programable thermostat. Battery operated £121.00
OUH3-HK Hooks OUH3-HK Suspension kit (four hooks and locknuts).  Not suitable for OUH3-40 £12.00

Technical Specification

Colour: Light grey case with black grille and bracket
Finish: Epoxy polyester powder coating
Construction: 1.2mm steel case
Fan: Motor mounted in cool compartment
Thermally protected motor
Totally enclosed and factory lubricated fan motor
Protection Devices: High-limit temperature control with automatic reset
Heat purge device clears residual heat
Heating Element: Stainless steel sheathed tubular heating elements
Concentric formation for optimum heat transfer
Control: Factory installed 230V fused control circuit
Factory installed contactor
Temperature control by means of factory fitted thermostat or choice of remote mounted thermostats.
Optional switch (OUH3-S) provides on/off/heat/fan only settings. Can be remote mounted or fitted to the rear of a heater
Built-in relays allow a group of heaters to be controlled by a single OUH3-S control switch,  thermostat or other controller
Installation: Specially designed bracket for ceiling or wall-mounting provides a variety of discharge angles and 360⁰ rotation
Suspension hooks are supplied as an optional extra part No. OUH3-HK  (Not suitable for OUH3-40)
Maximum recommended mounting height (3kW to 9kW): 2.5m (horizontal discharge), 3m (vertical discharge)
Maximum recommended mounting height (15kW to 40kW): 3m (horizontal discharge), 3.5m (vertical discharge)

Maximum operating ambient temperature:  30°C
Guarantee: 5 year (assuming standard comfort heating application)
OUH2 installed in a workshop in Billingshurst, West Sussex

OUH3 heaters are the most rugged and reliable industrial fan heaters on the market 

Performance Data

Model   kW Volts Airflow (m³/h) Approximate Temperature Rise (⁰C) dB*@ 2m
OUH3-03 3 230V 1100 7 60
OUH3-06 6 230V 1100 13 60
OUH3-09 9 230V or 400V/3N 1100 23 60
OUH3-15 15 400V/3N 3150 13 62
OUH3-20 20 400V/3N 3150 17 62
OUH3-25 25 400V/3N 3150 22 62
OUH3-40 25 400V/3N 5600 20 64

* Noise levels are factory tested, not laboratory tested.

Physical Data

kW Height (mm) Width (mm) Depth (mm) Weight (kg)
3 to 9 320 435 405 18
15 to 25 445 565 485 37
40 582 642 765 56

Spare Components

This is a list of the more frequently requested spare components.  Should you require a component that is not listed please contact BN Thermic.

Part No. Description Suitable For
40000 3kW Heating Element OUH3-03/06/09
40001 1kW Heating Element OUH2-03
40003 1.66kW  Heating Element OUH2-05
40004 2.5kW Heating Element OUH2-07
40002 3.3kW Heating Element OUH2-10
40005 5kW Heating Element OUH2-15 & OUH3-15
40006 6.66kW Heating Element OUH2-20 & OUH3-20/40
40007 8.33kW Heating Element OUH2-25 & OUH3-25
50031 Motor/Fan Assembly OUH2-03/05/07/10 &
50035 Motor/Fan Assembly OUH2-15/20/25 &
50048 Motor/Fan Assembly OUH3-40
80152 Contactor OUH3-03/06/09
CON-32 Contactor OUH2-03/05/07/10
CON-50 Contactor OUH2-15/20/25 &
80150 Relay All models
80252 Heat Purge Device All models
80254 High Limit Device All models
80250 Factory Fitted Thermostat All models
OUH2 Unit heater suspended using hooks provided

All OUH3-03 to 25 Unit heaters can be easily suspended using the optional hanging hooks (part No. OUH3-HK) Do Not hang the OUH3-40

OUH2 wall mounted in a warehouse in Axminster, Devon

OUH3 industrial fan heaters can be used for frost protection or to keep staff warm 


If you would like the experts at BN Thermic to select a suitable heating for your application, please click here to access our enquiry form.  Simply provide as much information as you have available and we will respond with a detailed proposal.

Enquiry Form

In simple terms the output of the installed OUH3 industrial fan heater or heaters must be greater than the heat losses from the building during periods of cold weather.  A small amount of heat is lost through the walls, ceilings and floors with more significant losses through windows and doors.

To estimate the heat loss from your building you may like to use our heat loss tool

Heat Calculator

The estimated heat loss figure is the absolute minimum kW output that you should consider installing.  We would suggest adding approximately 50% to this figure to allow for an acceptable warm up time in cold conditions as well as making allowances for exceptional weather conditions and possible errors in the original data used in the estimate.

Once the target kW has been estimated it is generally as simple as selecting the minimum quantity of heater required to provide that output.  Select from the following table.

Model kW Volts Airflow  (m³/h)   
OUH3-03 3 230V 1100
OUH3-06 6 230V 1100
OUH3-09 9 230V or 400V/3N 1100
OUH3-15 15 400V/3N 3150
OUH3-20 20 400V/3N 3150
OUH3-25 25 400V/3N 3150
OUH3-40 40 400V/3N 5600

For perfect heat distribution the combined air volume flow rate of the selected heaters should also be considered.  Ideally the total air volume processed by the heaters every hour should be at least four times the total air volume in the building.  In some cases therefore, you may choose to select a larger number of lower output heaters in order to increase the total quantity of air processed every hour.


When using OUH3 industrial fan heaters in a building with a roof height in excess of 4m, the installation of a DSU3 destratification unit is strongly recommended.  This device will recycle warm air that has accumulated at high level thereby reducing heating bills by up to 30%.  It should also be noted that DSU3 destratification units provide very high air volume flow rates and often enable the ‘four times total air volume’ target to be achieved without needing to consider additional heaters.

DSU2 Destratification Unit