For plumbing, pick a thermometer that handles shiny pipe and water: the Fluke 62 Max has adjustable emissivity for copper and brass, and the Klein IR07 adds a contact probe for reading water at the tap. The Klein IR1 is a simple fixed-emissivity meter for painted or plastic surfaces, and the Klein ET05 is a pocket probe for water. Bare copper reads low on a fixed 0.95 meter unless you tape or probe it.
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This guide covers handheld infrared and probe thermometers for plumbing and heating work.
IR thermometers for plumbing compared
| Model | Emissivity | Choose it when |
|---|---|---|
| Fluke 62 Max | Adjustable 0.10 to 1.00 | You read copper, brass or other shiny surfaces and want to correct for them |
| Klein IR07 | Infrared plus a contact probe | You want to read water temperature directly with the probe |
| Klein IR1 | Fixed at 0.95 | Simple checks on painted, plastic or insulated surfaces |
An infrared thermometer reads the heat a surface gives off. Matte and painted surfaces give off heat close to what the meter assumes. Bare copper, brass and chrome give off much less, so a meter set for 0.95 reads them too low.
The shiny-pipe problem and how to work around it
Emissivity is how well a surface radiates heat. Klein lists its IR1 (kleintools.com) at a fixed emissivity of 0.95. Fluke lists the 62 Max (fluke.com) with emissivity adjustable from 0.10 to 1.00.
On bare copper or brass, a fixed-0.95 meter will read low. Three ways around it: set a lower emissivity on an adjustable meter, put a piece of matte electrical tape or a dab of flat paint on the pipe and read that spot after it warms, or use a contact probe.
For water temperature itself, the most direct method is a probe in the stream at the tap, not an infrared reading of the faucet body.
Fluke 62 Max: adjustable emissivity and IP54
Choose the Fluke 62 Max if you read a lot of bare metal pipe. Fluke’s page (fluke.com) lists a range of −22 to 932°F, accuracy of ±1.5°C or ±1.5% of reading (whichever is greater), a 10:1 distance-to-spot ratio, single-laser targeting, adjustable emissivity from 0.10 to 1.00 and an IP54 rating against dust and moisture.
On October 15, 2026, the standard new offer sold by Amazon.com showed stock with model FLUKE-62 MAX.
Check Fluke 62 Max infrared thermometer on Amazon →
Klein IR07: infrared plus a probe for water
Choose the Klein IR07 if you mostly need water temperature. The listing describes an 8:1 infrared reading, a range of −40 to 752°F, and a temperature probe for air vents, ducts and liquids with a hanging hook, plus a differential (T1−T2) reading between the infrared and probe values.
That probe is the practical way to check hot water at a tap or a mixing valve outlet. On October 15, 2026, the standard new offer sold by Amazon.com showed stock with model and part IR07.
Check Klein IR07 infrared and probe thermometer on Amazon →
Klein IR1: a simple fixed-emissivity meter
Choose the Klein IR1 for quick checks on painted, plastic or insulated surfaces. Klein’s page (kleintools.com) lists a 10:1 distance-to-spot ratio, −4 to 752°F range, fixed emissivity at 0.95, a targeting laser, auto-hold, backlit display, drop protection to 6.6 feet, and accuracy above freezing of ±4°F or ±2%.
Klein says it is not a medical device and not intended for people or animals. On October 15, 2026, the standard new offer sold by Amazon.com showed stock with model and part IR1.
Check Klein IR1 infrared thermometer on Amazon →
Klein ET05: a pocket probe thermometer
Choose the Klein ET05 if you want a dedicated pocket probe for water and air. The listing gives a range of −40 to 482°F, Fahrenheit or Celsius, a backlit display, and max/min, hold and average functions, and notes it is not a medical device.
A pocket probe reads the water itself, so emissivity does not matter. Run the tap until the temperature stops climbing, hold the probe tip in the stream, and wait for the reading to settle before you note it.
It helps to carry both: an infrared meter to scan pipes and equipment quickly, and a probe to confirm the actual water temperature. The Klein IR07 combines the two in one body if you would rather carry a single tool.
On October 15, 2026, the standard new offer sold by Amazon.com showed stock with model and part ET05.
Check Klein ET05 digital pocket thermometer on Amazon →
Plumbing jobs where a thermometer helps
Checking a mixing valve: read the outlet water with a probe after the valve and compare with the setting. Our thermostatic mixing valve guide covers adjustment.
Diagnosing a water heater: compare hot water at the tap with the thermostat setting. Our water heater thermostat guide explains what to check next.
Finding frozen sections: on a cold run, scan along the pipe for the coldest spot. Use the tape trick on bare copper so the reading is not falsely low. Our thawing guide covers safe thawing methods.
Radiant and hydronic loops: compare supply and return temperatures to spot a loop that is not flowing.
What an infrared thermometer cannot do
It reads one spot on a surface. It cannot see through walls, inside a pipe, or through glass, and it averages everything inside its spot. A reading on a painted wall over a hidden pipe tells you about the wall, not the water.
To find a hidden leak or a hot-water line inside a wall or slab, a thermal camera shows a picture of the whole area instead of one number. Our thermal camera guide covers when that is worth it.
An infrared meter also does not replace the gauges and controls on equipment. Use it to compare, confirm and narrow down a problem, then check the equipment maker’s procedure before you adjust anything on a water heater or boiler.
Distance-to-spot and getting a clean reading
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The ratio tells you how big the measured spot is at a given distance. At 10:1, standing 10 inches away measures a spot about 1 inch across. Get close enough that the spot is smaller than the pipe, or you will average in the wall behind it.
Hold the meter steady and take more than one reading. Steam, dirt and condensation on a pipe change what the meter sees; wipe the surface if you can.
Write readings down with the time and location. On a water heater or mixing valve job, a before-and-after pair of numbers is the clearest proof that the repair worked, and it gives you a baseline the next time the customer calls.
Frequently asked questions
Why does my infrared thermometer read copper pipe too cold?
Bare copper has low emissivity, so a meter set at 0.95 reads it low. Use adjustable emissivity, a piece of matte tape on the pipe, or a contact probe.
What is the best way to measure hot water temperature?
Put a probe thermometer in the water stream at the tap. The Klein IR07 includes a probe for liquids.
Does the Fluke 62 Max have adjustable emissivity?
Yes. Fluke lists it as adjustable from 0.10 to 1.00.
What does 10:1 distance-to-spot mean?
At 10 inches away the meter reads a spot about 1 inch across. Get closer for small pipes.
Can I use these thermometers on people?
No. Klein says the IR1 is not a medical device and not for people or animals.
How we chose
This document-based guide makes no hands-on testing claim. We read Klein’s IR1 product page and Fluke’s 62 Max product page, and the Klein IR07 listing. On October 15, 2026, all three linked standard new offers were sold by Amazon.com and showed stock. Read our selection method and about Plumbing Picks.
Primary sources
- Klein Tools IR1 infrared thermometer (kleintools.com): 10:1, −4 to 752°F, fixed emissivity 0.95, accuracy, drop rating, not medical.
- Fluke 62 Max infrared thermometer (fluke.com): −22 to 932°F, ±1.5°C/1.5%, 10:1, emissivity 0.10–1.00, IP54.