Wohler part# 3356

$1,890.00 $1,701.00

The Wohler A 400 PRO 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 4 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 4 year warranty on instrument including sensors1)
  • 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


Wöhler A400 PRO Flue Gas Analyzer – Standard Set