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Top 5 Best Combustion Analyzer Reviewed [Home & Commercial] is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to As an Amazon Associate this site earns from qualifying purchases.

combustion analyzer

What is the best combustion analyzer on the market in 2022? That’s exactly what we will answer today with our selection of 5 analyzers covering a range of price points and features.

Whether you’re an HVAC technician dealing with commercial scenarios, or simply need to check the combustion levels of your home system, we have selected a machine that will meet your needs.

For our top choices at a glance, check out the summaries below. For an in-depth review of each of the combustion analyzers, keep on reading.

Best Combustion Analyzer

EDITORS CHOICE: Bacharach Fyrite Intech Combustion Analyzer

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The Bacharach Fyrite Intech Combustion Analyzer is our editor’s choice because of its overall usability. Fast, accurate, and at a great price point this device is a top-quality solution for calculating the efficiency of residential furnaces and combustion appliances.

BEST BUDGET: Fieldpiece SOX3 Combustion Analyzer

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If you’re looking for an affordable tool that will provide the most important furnace health checks, the Fieldpiece SOX3 is the tool to buy.

While it won’t offer the range of analysis you will get from one of the premium units in our top 5, and its current price point the SOX3 deserves to be in all HVAC tool bags.

BEST PREMIUM: Testo 320 Residential/Commercial Combustion Analyzer Kit

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If you are an HVAC technician looking for a Combustion Analyzer Kit for both residential and commercial applications, the Testo 320 is the unit to buy.

The unit and the included accessories provide everything you need to get the job done. Our top pick premium analyzer for good reason.

Factors before you buy

When buying an analyzer there are a number of factors to consider first.

What are the different types of measurements and calculations you need to take? The unit clearly has to be able to carry out the applicable tests.

Ease and speed of use are also important, especially if you are a busy technician. Your workflow will be more efficient with a unit that is simple to use, provides clear data (with a means to record it), and allows for infield sensor replacement.

There’s also the issue of portability and build quality. These tools can get knocked around, so they need to be built to last.

In this review round-up, we have backed up our selections with verified customer reviews alongside intensive product research and analysis.

Based on these rating criteria and more, the following 5 models are what we consider to be the best combustion analyzers on the market in 2022.

Combustion Analyzer Reviews

1. EDITORS CHOICE: Bacharach Fyrite Intech Combustion Analyzer Review

We’ve selected the Bacharach Fyrite Intech Combustion Analyzer as our top pick for 2022 because it balances price point with superior features better than the competition. It is also made in America.

The specs truly are great on this machine. Designed to accurately measure oxygen, carbon monoxide, stack temperature and ambient temperatures, the functionality you get from unit is impressive.

Furthermore, your workflow will be made more efficient due to the speed at which the Bacharach Fyrite can take these measurements.

Call-out times are greatly reduced when you have access to test results instantly. And that’s exactly what the machine provides.

The easy-to-use interface has 6 selectable fuel types. These options are displayed on a high-contrast LCD that even has a backlight when you find yourself in dim working conditions.

Adding to the increased work efficiency is the fact you can store 10 complete records within the on-board memory.

This data can also be output via a wireless printer, (sold separately on this particular offering).

The unit features what Bacharach calls B-Smart sensor technology. Various sensors are included in the kit, enabling the user to calculate the efficiency of residential furnaces and combustion appliances.

Furthermore, these sensors provide Plug-n-play functionality. The fact they are pre-calibrated enables simple in-field replacement. Once again, your workflow is made more efficient because instrument downtime is reduced.

Finally, we should mention the superior build quality too. The Fyrite Intech Combustion Analyzer has a genuine robust feel to the way it is made.

The manufacturers have basically managed to create a rugged handheld unit that is still lightweight and easy to use. Kudos to them.




Stack temperature

Ambient air temperature



0 to 20.9%

0 to 2000 ppm

-4 to 1202 °F (-20 to 650 °C)

-4 to 212 °F (-20 to 100 °C)

2.7 in. (69 mm) monochrome LCD w/backlight
4x AA batteries
Run Time
15 hours minimum (alkaline batteries)
Size (H x W x D)
8.0 x 3.6 x 2.3 in. (20.3 x 9.1 x 5.8 cm)
1 lb. (0.45 kg) including batteries
Fuels [1]
Natural gas, oil 2/6, kerosene, propane, butane, LPG, B5, KOKS, LEG, biofuel
Operating Conditions
23 to 113 °F (-5 to 45 °C), 15 to 90% RH (non-condensing), 1 ATM ± 10%
Warm-up Time
30 to 60 seconds
10 locations
USB 2.0 (mini-B), IrDA
CE mark, EN 50379-1 & -3
2 years (including sensors)

InTech DataSheet
What's Included
  • O2 sensor,
  • CO Sensor,
  • Probe,
  • Rubber Boot,
  • Spare Filters,
  • Printer,
  • User Software,
  • USB Cable,
  • 8 AA Batteries
  • Hard Carry Case
Pros of the Bacharach Fyrite Intech Combustion Analyzer
  • Affordable combustion analyzer with superior features
  • Plug & Play, B-Smart pre-calibrated sensors
  • Instant measurements to speed up workflow
  • An LCD display with clear output
  • Internal memory (stores 10 complete records)
  • High-quality construction with a rugged design
The Cons
  • It is a shame that the Fyrite Intech cannot perfom draft tests.

2. Testo 310 Residential Combustion Analyzer Kit Review

The Testo 310 Residential Combustion Analyzer is another lower-priced unit to make our top 5 round-up.

For technicians or homeowners on a budget, this is an affordable way of conducting flue gas analysis.

The versatility of the unit also means you can check furnace efficiency, boiler tuning, as well as water heater examinations.

Again, measurements are easy to take and the response time is fast, (a mere 30-seconds startup before testing instruments are ready). The integrated probe is kink-resistant in order to eliminate leaks.

Draft and pressure measurements are available of course. There’s also the ability to choose from 5 different fuel types. This preset data will help provide you with the most accurate measurements.

Testo has fitted the handheld 310 with a bright backlit, 2 line display. This provides an easy to read method of viewing important data and selection parameters.

Finally, there is the issue of build quality. While not in the realm of some of the more premium units in our top 5, the Testo 310 is still a rugged little beast that is built to stand the test of time.

8 x 3 x 2 in. / 201 x 83 x 44 mm
Operating temperature
23° to 113 °F / -5 to +45 °C
Display type
Display function
Backlit 2-line display
Power supply
Battery: 1500 mAh, mains unit 5V/1A
Storage temperature
-4° to 122 °F / -20 to +50 °C
(with probe) Approx. 25 oz. / (with probe) Approx. 700 g

For full measurement, specifications head here.

Pros of the Testo 310 Residential Combustion Analyzer Kit
  • A versatile device with a wide range of measurement function
  • 5 fuel types as preset data
  • Bright backlit 2-line display.
  • Fast 30-second startup
  • Affordable and well build
The Cons
  • The sensors are expensive to replace
  • One Amazon user was sent a defective product that seemed to be used.

Bottom Line

The testo 310 residential combustion analyser is a good device. While it doesn’t have the same level of functionality as our top pick, it is still a reliable machine that will accurately take a wide range of measurements.

3. BEST BUDGET: Fieldpiece SOX3 Combustion Check Review

For sheer price-busting value for money, the Fieldpiece SOX3 gets our top budget unit award. This really is an excellent tool for the price.

However, it should be noted that this will not provide full combustion analysis; rather, it is meant as a tool to be used for easily tuning furnaces when required.

This makes it a great tool for HVAC technicians that need to carry out rudimentary measurements on the job.

Flue temp and oxygen percentage can all be measured using the SOX3. The device is also able to calculate carbon dioxide percentage and combustion efficiency.

For service professionals that need it, FieldPiece has added EA percentage capabilities too.

The device is also easy to use. It incorporates an automatic electric pump saving you from trying to hand pump as you take readings. This system has a pause button too, which enables better user control, (it also helps to extend battery life).

Another great design feature is the sensor indicators. The SOX3 is able to tell you when a sensor requires changing.

As long as you have the calibration data stored on the device, you can swap out the old sensor and replace it with another. No downtime as you work; no need to send the unit off to be calibrated.

Pros of the Fieldpiece SOX3 Combustion Checker
  • Very affordable unit – designed for HVAC techs
  • measures O2%, flue temp and combustion efficiency.
  • Calculates percent CO2 and percent excess air
  • In-built automatic electric pump with pause
  • Field-replaceable Oxygen Sensors – avoids downtime
The Cons
  • The unit doesn’t show ( ppm ) parts-per-million
  • The oxygen sensor has a life of 2 years before sensor replacement required

4. UEi Test Instruments C85KIT EOS Combustion Analyzer Kit Review

The UEi Combustion Analyzer Kit makes our top 5 based on the good all-round performance that it provides, as well as the comprehensive list of accessories that are shipped with it.

Designed as a residential portable combustion analyzer, the system actually has UEi’s exclusive eos CO2 measurement technology built-in.

For technicians familiar with some of their previous product offerings, the C85 is based on the C75 model that has proved very popular over recent years.

One of the major updates is the fact UEi has fitted a long-life oxygen sensor to the C85, ensuring that you will not have to carry out expensive replacements later in the sensor’s life.

Another premium feature within the C85 that is clearly aimed at the professional is the 21 memory positions. Record calibrations directly within the unit to cover all manner of measurement jobs.

And on the subject of measurements, what can the C85 do? Well the obvious CO2, CO, and Flue temperatures can all be recorded.

The system will also calculate O2, efficiency, excess air, CO air free, (CO readings are to 1 ppm).

For easy reading of the outputs, the system has a built-in, 2 line backlit display. The device is also fitted with a protective boot complete with an integrated magnet.

With UEi having over 60 years’ experience designing and manufacturing testing devices this is a brand you can trust.

However, for peace of mind, you also get a 5 Year limited warranty (includes sensors) on the C85.

Temperature Measurements
Parameter Range Resolution Accuracy
Flue Temperature 32 to 1112 °F (0 to 600 °C) 1.0 °F/°C ±5 °F (2 °C) ±0.3% reading
Inlet temperature 32 to 212 °F (0 to 100 °C) 1.0 °F/°C ±1 °F/°C ±0.3% reading
Temp (Nett)*2 32 to 1112 °F (0 to 600 °C) 1.0 °F/°C ±5 °F (2 °C) ±0.3% reading
Gas Measurements
Parameter Range Resolution Accuracy
Carbon Monoxide (CO)
0 to 1999 ppm
1 ppm
±5 ppm <100 ppm
±5% reading >100 ppm
Carbon Dioxide (CO2) 0 to 30% 0.1% ±0.3%
Parameter Range Resolution Accuracy
Oxygen (O2) 0 to 21% 0.1% ±0.2%
Efficiency 0 to 99.9% 0.1% ±1.0%
Excess Air 0 to 250% 0.1% ±0.2%
Pros of the UEi Test Instruments C85KIT EOS Combustion Analyzer Kit
  • Wide ramge of measurements and calculations
  • Extensive accessories kit
  • Electro optical CO2 sensor technology
  • 20 memory positions
  • 5 year warranty
The Cons
  • More expensive than our editors choice despite having similar features

Bottom Line

The C85 benefits from UEi’s extensive track record for providing quality products to the testing market. Packed with functionality this is a go-to tool you’ll be pleased to own when analysing combustion. Highly recommended.

5. BEST PREMIUM: Testo 320 Residential/Commercial Combustion Analyzer Kit Review

For those looking for a combustion analyzer kit for both residential and commercial scenarios, the Testo 320 is our number one premium pick.

Designed to be used in all combustion measurement situations, the 320 has sophisticated sensors to provide the accuracy you need.

The list is long on what this unit can measure, however as a taster the range includes flue draught measurement, pressure measurement, as well as gas leak detection. (see the tab below for the full specifications).

All data is displayed in color on the HD graphic display. Furthermore, the Testo 320 has the capability to show up to 8 parameters simultaneously.

This makes it a lot easier for the HVAC technician to compare and calculate important data responses.

Ease of use is actually a priority in the design of the system. Self-explanatory menu guidance complete with standardized measuring procedures makes for a unit that is quick to get accustomed to. The result is quick and easy handling and a faster work rate.

Being a kit designed for the working professional, the accessories that come with the Testo 320 are very beneficial. The flue gas probe, and included IR printer being notable highlights.

Dimensions 9° x 3 in. / 240 x 85 x 65 mm
Operating temperature 23° to 113 °F / -5 to +45 °C
Protection class IP40
Display size 240 x 320 pixels
Display function Colour graphic display
Power supply Battery: 3.7 V / 2,400 mAh; Mains unit: 5 V / 1 A
Storage temperature -4° to 122 °F / -20 to +50 °C
Weight 20 oz. / 573 g
Package Includes

Testo 320 flue gas analyzer with O2 and CO sensor (without H2 compensation), USB mains unit, compact basic flue gas probe, IR printer, thermal paper, replacement filters, and instrument case.

Pros of the Testo 320 Residential/Commercial Combustion Analyzer Kit
  • Residential & commercial application
  • Widest range of features in our top 5
  • Lots of accessories including printer and gas probe
  • HD display with up to 8 parameters displayed at one time
The Cons
  • The most expensive package in our top 5

Combustion Analyzer Buyer’s Guide

What to consider when buying a Combustion Analyzer?

The product itself is small but often has several attachments along with it. So, you should be aware of a few things before you buy a combustion analyzer.

Different types of Gas Detection

Whether you’re a professional looking for a work-horse, or an at-home user needing a residential device, the combustion analyzer you buy really should be able to detect more than one type of gas.

Measuring excess CO2 levels is of course a must, however, beyond this a unit that can detect compounds of oxygen and nitrogen is recommended.

Versatile Sensors

There will be times where you will need to take readings in hard-to-reach places. To this end, a device that has sensors in the form of extra attachments will be extremely useful. This will allow you to feed a sensor around the back of appliances to take measurements.

You can also purchase analyzers that have a magnetic back. When placed into nooks and crannies around the side or rear of appliances, you are able to go hands-free with such a device.


The display on the analyzer needs to be large enough for you to see what data is being displayed. It should also be backlit so that you can take readings in low-light conditions.

The display should also be robust and well protected, especially on professional devices. These tools can get knocked about. A combustion analyzer with a broken screen is borderline useless.


The unit you buy should provide clear readings without the need for confusing calculations on the part of the user. This is essential whether your a beginner or otherwise.

A unit with in-built logic analyzers will be able to perform calculations at the touch of a button. Pay close attention to the specifications in order to ascertain the capabilities of the device you are interested in.

USB and/or WiFi connectivity

A device with USB ports will make it easy to connect to external devices such as a laptop (or extra sensors as mentioned earlier).

WiFi connectivity is also beneficial if you want to hook up the device to a printer or laptop/tablet. Analyzers with this kind of feature will be more expensive, however.

Combustion Analyzer FAQs


Q. What is the purpose of combustion Analyzers?

A combustion analyzer will detect whether an appliance is releasing unburned hydrocarbons (I % level = a 10% loss in Combustion Efficiency).

Q. Can I change the location settings after set-up?

Yes, the majority of devices will allow you to change the location settings. However, on some lower budget units this can be a time-consuming process you will not want to do often

Q.Will I be able to detect more than one compound using a combustion analyzer?

Most models will have the capability to detect more than one type of gas. However, the amount and the accuracy will vary amongst devices.

Q. How often should I change the filter inside the combustion analyzer?

This depends on how often you use the device. It is important to regularly check the filter for the build-up of dirt and dust. Too clogged and you will end up with inaccurate readings.

Q. How often should I recalibrate my combustion analyzer?

This is generally between 6 months and 1 year. Some devices will have these details in the user manual. Premium units will actually alert you to when this should be done.

It is important to ensure your analyzer is sufficiently calibrated in order to maintain accurate results.

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