Wrong Website?

You are currently on the American website.

+1 978 750 9876
RMA Request

Callback Form

or call +1 978 750 9876

* Required Entry
Wohler A 400 L Flue Gas Analyzers

Wohler A 400 L Flue Gas Analyzers

Combustion with one hand

The Wohler A 400 L Flue Gas Analyzers are the multi-functional combustion analyzers (flue gas, differential pressure, ambient CO) for residential and light commercial applications. Its unique design allows a comfortable one-hand operation with a technician-friendly 4 button key pad. Integrated magnets make even a hands-free operation possible. Your eyes will love the brilliant full color OLED display which shows all combustion values on one screen. The self-diagnosis function with an alarm makes this combustion analyzer reliable and failsafe. We provide full 2 year warranty for this gas analyzer and LT-Sensors.

Features and Benefits

  • Color OLED display – all combustion data values on one screen
  • Zoom function
  • Integrated magnetic holder
  • Technician-friendly 4 button keypad
  • Ergonomic shape: comfortable one-hand operation
  • Graphic function
  • User selectable units for temperature, pressure and CO

Safety / Reliability

  • Integrated 4-filter technology including water stop filter, cotton filter, sample conditioner and sensor protection LT-sensors1)
  • Full 2 year warranty on Wohler A 400 L models
  • Continuous self-diagnosis with feedback for:
    • All sensors
    • Instrument functions
    • Condensate

Data Management

  • Memory for 100 customer records
  • Date and time stamp

Variety of Applications

  • Wohler Tuning Guide with graphical support
  • Combustion and efficiency analyzer for residential and light commercial applications
  • Ambient CO tester
  • Flue gas CO tester (CO air free)
  • Differential manometer for chimney draft and appliance manifold pressure
  • Graph feature for all combustion readings


  • TÜV approved
  • EN 50379-2
  • EN 50379-1 for CO

Comparison Chart

A 400 L
A 400 PRO
Manifold and Differential Pressure
Tuning Guide
Data Management
CO2 (0...21%)
CO 0...10,000 ppm 0...4,000 ppm
NO (0...1,000 ppm)  
Stack Temperature -4...1,472 °F -4...1,472 °F
Supply Air Temperature -4...248 °F -4...248 °F
Differential Pressure 44.15 inWC 44.15 inWC
Operation Features    
Full Color Display
Infrared port for printer
Safety Features    
Warranty 24 months 48 months
Self Diagnosis for Sensors and Instrument
4 Filter Technology
Filter and Pump Monitor
Field Replaceable Sensors and Longtime Sensors F F/L
Sort By
Item no.
Show all products
Sort By
Item no.
Show all products
Sort By
Item no.
Show all products
Register Your Product
Wohler USA wants to insure that our customers get the best possible service. By filling out the form, we can have accurate information on your equipment.
Find your local distributor
Get personalized local assistance with your sales and support needs.
Do you need help? Just call us!
Phone: +1 978 750 9876
Fax: +1 978 750 9799
Trade Show schedule
We are on the road! Check out our next events!