Description
UEI C165+ Residential / Commercial Combustion Analyzer
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Backed by UEi Service+ to allow up to 10 years’ warranty, same day recertification and a reduced cost of ownership. The C165+ Residential/Commercial Combustion Analyzer is easy to use with a rugged design, multiple sensor protections, altitude compensation and differential pressure. Prints to optional printer and wireless App. LINK connects the included wireless pipe clamp temperature probes and other optional probes to the C165+. Essential information for the installation and maintenance of furnaces and boilers – all in one place.
C165+ enables a LINK feature to connect to wireless probes. The LINK feature connects to the 2 wireless temperature pipe clamps (WPC2), which can be used to compare flow and return temperatures on a boiler. C165+ LINK also connects the optional DTHA2 (sold separately) to measure air flow. Contractors can use the Room CO test to take snap shots of ambient CO readings to view trending CO levels. C165+ has four types of sensor protection; an H2 compensated 10,000 ppm CO sensor, CO over-range purge pump, a NOx filtered CO sensor, and Low Flow Detection to protect the CO sensor. It offers differential pressure and has wireless capabilities to a Printer App for compatible iOS and Android devices. It also has sensor technology that reduces the cost of ownership. It features a Heat Exchanger test to check the exchanger integrity and differential temperature. The C165+ comes with High Altitude compensation to maintain accurate readings, auto-purge shut off, and 8 Pre-programmed fuels including Natural Gas and Propane.
The C165+ has a 6-Line display to view readings on one screen, which is a favorite among technicians. The DMM style dial makes it easy to select the test needed. It also features a water trap to protect the sensor with a check light to remind to look for condensate built-up, a magnetic boot for hands-free operations, and an IR printer port to print to the optional IR thermal printer, making it easy to document test results for later analysis.
NOTE: CO-AirFree (COa) Calculation can be set to be displayed in the AUX screen.
Product Features & Functions:
- Up to 6 Year warranty with annual recertification
- 3 Types of Sensor Protection
- NOx Filtered
- Link to Wireless Probes
- K-Type Temperature Inputs
- CO-AirFree (COa) Calculation
- Low Flow Detection
- Over Range Protection Pump
- Temp differential
- 6 line backlit display
- Dual Presssure Input
- Differential pressure
- 8 Preprogrammed Fuels
- 30 second start time
- High altitude compensation
- 30 Memory Positions
- Protective Water Trap
- Automatic fresh air purge
- Magnetic mount
- IR printer link (Printer not included)

Backed by UEi Service+ to give up to 10 years of warranty, SAME DAY GUARANTEED recertification, and a reduced cost of ownership.
- 10-Year Warranty: All UEi combustion analyzers have a standard 1-year warranty. Each recertification includes a full inspection and extends the warranty for 1 more year for up to 10 years from the date of purchase.
- Same Day Service: All qualifying analyzers received for recertification through UEi Service+ are returned the same business day, Guaranteed. (48 hours for analyzers with a NO (Nitric Oxide) sensor installed.)
- Free Shipping: UEi Service+ offers free shipping both to and from their service center. When customers book their recertification, they receive a prepaid UPS Ground shipping label.
UEi Service+ wins the 2024 Dealer Design GOLD Award for Contractor Services and Software

Specs
Parameter | Range | Resolution | Accuracy |
---|---|---|---|
Flue Temperature | 32-1112°F | 0.1°F | +3.6°F +0.3% reading |
Inlet Temperature (Internal sensor) | 32-112°F | 0.1°F | +1.8°C +0.3% reading |
Inlet Temperature (External sensor) | 32-1112°F | 0.1°F | +3.6°F +0.3% reading |
Oxygen | 0-21% | 0.1% | +0.3% |
Carbon monoxide | 0-20ppm | 1ppm | +3ppm +5% reading |
21-2,000ppm | |||
Above 2000ppm Purge pump operates | Unspecified | ||
Carbon dioxide | 0-20% | 0.1% | +0.3% volume |
Efficiency (Net or Gross) | 0-99.9% | 0.1% | +1.0% reading |
Efficiency High (C) | 0-119.9% | 0.1% | +1.0% reading |
Excess Air | 0-250% | 0.1% | +0.2% reading |
CO/CO2 ratio | 0-0.999 | 0.0001 | +5% reading |
CO-AirFree (COa) | 0 to 9999 PPM | 1 PPM | ±5% rdg |
Includes
- (1) UEI C165+ Residential / Commercial Combustion Analyzer
- (2) Wireless Pipe Clamp Probes
- (3) Rechargeable (AA)
- (1) AC509 Case
- (1) USB cable
- (1) Charger
- (1) Water trap
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