testo 320 - Flue Gas Analyser (Advanced Set)

Order-Nr.  0563 3220 78

  • Free Bluetooth connection to enable the analyser to be connected to Testo’s free Combustion App - Only on Android devices!

  • 5 applications with one instrument: measurement of flue, gas, draught, pressure, ambient COdifferential pressure and gas leak detection (with optional probe) 

  • Clear and simple colour menu - tests listed with icons and text

  • Independently tested according to EN 50379 Parts 1-3

The ideal equipment for heating engineers: with this testo 320 flue gas analysis set, you can carry out your measuring tasks on heating systems quickly and efficiently. Use the flue gas analyser to measure flue gas, draught, pressure, ambient CO2 and differential temperature. Can also detect gas leaks and ambient CO with an optional additional probe. 

Delivery time: 3 – 5 working days

Shipping costs

£ 690.00
incl. VAT  £ 828.00

Product Description

The testo 320 is a high-quality measuring instrument for efficient flue gas analysis. Its wide measuring range makes it a reliable partner for eliminating malfunctions and emergencies, monitoring legal limit values or for daily routine work servicing heating systems. The numerous measurement menus of the testo 320 are clearly structured. Standardised menu procedures, which are stored in the instrument specifically for your country, simplify operation – depending on which standards you are dealing with. The high-resolution display allows a detailed presentation of the measurement procedures and is easily legible even under the worst conditions.

testo 320 flue gas analysis set - High-efficiency instrument, practical accessories
  • Bluetooth connectivity to Android devices
  • Integrated traffic light system which continuously monitors the sensor functionality
  • Flue gas matrix screen including boiler type and parameters
  • Save up to 500 measurement protocols
  • High-resolution colour graphic display
  • Gas & Oil ratings
  • Smoke number/ HCT
  • Automatic zeroing of the sensor in only 30 seconds after start-up
  • Long service life thanks to the long-life Li-ion rechargeable battery
  • Built-in magnets enable the flue gas analyser to be attached to the burner/boiler quickly and easily
  • Integrated condensate trap: easy to empty
  • Optional gas leak probe for gas detection and gas pipe tests available - Selectable for methane or propane and detecting up to 10,000ppm
  • Optional CO and CO2 probes available for detailed measurement in ambient air or around boiler housings for instance
  • Changing probes is easy: the probes can be changed manually. You can order other optional probes specifically required for your flue gas analysis (e.g. multi-hole probe, dual wall clearance probe, flexible flue gas probe)
  • Single-hose connection: just one hand movement is needed to securely connect all channels for the flue gas measurement via the probe coupling (gas paths, draught, temperature probe integrated in the flue gas probe)


Delivery Scope

testo 320 Flue gas analyser with O2 & CO sensor and Bluetooth, International mains unit, Basic flue gas probe (180 mm, Ø 6 mm), Differential Pressure Set, Differential Temperature Set and hard carry case
Flue gas CO (without H₂-compensation)

Measuring range

0 to 4000 ppm


±20 ppm (0 to 400 ppm)

±5 % of mv (401 to 2000 ppm)

±10 % of mv (2001 to 4000 ppm)


1 ppm

Reaction time t₉₀

< 60 s


£ 142.00
incl. VAT  £ 170.40


£ 59.00
incl. VAT  £ 70.80
USB mains unit incl. cable

Order Number: 0554 1105

£ 36.50
incl. VAT  £ 43.80
easyheat PC analysis software

Order Number: 0554 3332

£ 99.00
incl. VAT  £ 118.80
CPA 1 Accessory Kit

Order Number: 300554 1000

£ 185.00
incl. VAT  £ 222.00

Accessories for measuring instrument

£ 22.00
incl. VAT  £ 26.40


£ 77.00
incl. VAT  £ 92.40

Printer and accessories

testo fast printer IRDA

Order Number: 0554 0549

£ 199.00
incl. VAT  £ 238.80
£ 24.00
incl. VAT  £ 28.80

Measuring the flue gas parameters of the burner (CO, O2, and temperature, etc.)

The flue gas measurement for a heating system helps to establish the pollutants released with the flue gas (e.g. carbon monoxide CO or carbon dioxide CO2) and the heating energy lost with the warm flue gas. In some countries, flue gas measurement is a legal requirement. It primarily has two objectives:


  • Ensuring the atmosphere is contaminated as little as possible by pollutants; and
  • energy is used as efficiently as possible.


Stipulated pollutant quantities per flue gas volume and energy losses must never be exceeded. Measurement in terms of results required by law takes place during standard operation (every performance primarily using the appliance). Using a Lambda probe (single hole or multi-hole probe), the measurement is taken at the centre of flow in the connecting pipe (in the centre of the pipe cross-section, not at the edge) between the boiler and chimney/flue. The measured values are recorded by the flue gas analyzer and can be logged either for print out or transfer to a PC at a later stage.

Measurement is taken by the installer at commissioning, and if necessary four weeks later by the flue gas inspector/chimney sweep, and then at regular intervals by the authorised service engineer.

Measuring pressure on burners (nozzle pressure, gas flow pressure, etc.)

Standard readings taken during services of domestic heating systems include checking the gas pressure on the burners. This involves measuring the gas flow pressure and gas resting pressure. The flow pressure, also called supplied pressure, refers to the gas pressure of the flowing gas and resting pressure of the static gas. If the flow pressure for gas boilers is slightly outside the 18 to 25 mbar range, adjustments must not be made and the boiler must not be put into operation. If put into operation nonetheless, the burner will not be able to function properly, and explosions will occur when setting the flame and ultimately malfunctions; the burner will therefore fail and the heating system will shut down.

Measuring temperatures on radiators

When measuring the temperature on radiators, the flow and return temperatures are recorded in particular and assessed by the tradesman. The flow temperature is defined as the temperature of a thermal transfer medium (e.g. water) that the system is supplied with. The temperature of the medium flowing out of the system is accordingly called the return temperature. To prevent losses within the heat distribution system and achieve a better level of efficiency in modern, heating technology, spot recording of flow and return temperatures is necessary at certain radiator pipes or screw fittings. Implementation of relevant measures ultimately leads to hydraulic adjustment on the basis of knowledge about the flow and return temperatures. This defines a procedure with which every radiator or heating circuit of a flat radiator within a heating system is supplied at a set flow temperature with the precise amount of heat needed to achieve the ambient temperature required for the individual rooms. Flawed operating conditions will result in considerable excess consumption of electricity and heating energy.

Product Brochures



  • Download testo 320 firmware  (V1.11, BIN, 13.053 KB) It is partially not possible to execute a firmware update with Windows 8.1 / Windows 10. This can be solved by installing a new Bootloader once.
    A description and all necessary files can be found under Update-Kit / Bootloader

  • Software EasyHeat for testo 300, 312-4, 320, 324, 330, 380  (v2.12 SP3, EXE, 101.938 KB) If you already have the testo EasyHeat software installed, your version will be updated. The update is possible with every version of the testo EasyHeat. This version can also be used as a demo version for  costumers who don't have installed the testo easyheat software at the moment. It will void after 30-days, but can be activated with a serial code at every time.

  • Instruction manual EasyHeat software  (PDF, 3.053 KB)

  • Testo ZIV driver ZIV 2000 for testo 320 and testo 330  (ZIP, 8.8 MB) Testo ZIV driver in the 2000 version. The Testo ZIV driver is used to connect the testo 320 and testo 330 measuring instruments to an application program (sweeping district administration program) according to the interface Version 2.0 defined by the Zentralverband des Schornsteinfegerhandwerks (Central Association of Chimney Sweeps, ZIV). Please check with the manufacturer of your application program as to whether this interface is supported. If Microsoft .NET Framework 4.0 has not been installed on the computer, it must be downloaded from the Microsoft website and installed on the system.

  • Testo ZIV driver for testo 300, testo 320 and testo 330   (v2.2 SP3, EXE, 64.193 KB) The Testo ZIV driver is used to connect the testo 300, testo 320 and testo 330 measuring instruments to an application program (sweeping district administration program) according to the interface defined by the Zentralverband des Schornsteinfegerhandwerks (ZIV, Central Association of Chimney Sweeps) in version 1.0 of 01. August 2012 as well as in version 2.0 of 13. February 2017. Please check with the manufacturer of your application program as to whether this interface is supported.