How to Test a 240 Volt Dryer Outlet with a Multimeter
As an Amazon Associate, we earn from qualifying purchases. How to test a dryer outlet 240 volt with a multimeter comes down to a few careful steps. Turn off the double-pole breaker, unplug the dryer, and confirm the meter works on a known source before you open anything. Then, with the breaker back on and the dryer still unplugged, measure about 240 V between the two hot slots and about 120 V from each hot slot to neutral or ground. This how-to walks through the steps, the readings that point to a fault, the safety checks that come first, and the points where a licensed electrician should take over.
Quick answer
A healthy 240 volt dryer outlet reads about 240 V between the two hot slots and about 120 V from each hot slot to neutral or ground. Make the measurement with the breaker on and the dryer unplugged. A reading near zero on one leg, or a hot-to-hot reading far from 240 V, means the circuit needs an electrician.
Before you start
A dryer outlet is a 240 V circuit, and it is fed by a double-pole breaker, usually rated at 30 amps in a typical US home. Work on it only with the dryer unplugged and the breaker off during any physical work. The test itself requires power, so you will switch the breaker on for the measurement and off again afterward. Keep the cover plate off only for the time needed to measure, and never leave bare conductors exposed.
Check your meter and leads before you start. The leads should be undamaged, and the meter should have an AC voltage function with a range above 250 V. A manual-ranging meter should be set to a range higher than 240 V, while an auto-ranging meter will choose its own range. Use a meter and leads rated for the circuit. Our guide to the best 3 prong outlet tester covers the simpler receptacle checks, and it is a useful first step before you open a dryer circuit.
Step 1: Confirm the breaker and the outlet
Switch off the double-pole breaker that feeds the dryer, then unplug the dryer from the outlet. Remove the outlet cover plate and look at the receptacle for burn marks, looseness, moisture or cracked housing. If you see any of those, stop and call an electrician. Ask-the-electrician describes the same basic start: identify the circuit, turn it off and tag it with a note before you inspect or modify the wiring.
Step 2: Set the meter for AC volts
Plug the black lead into the COM jack and the red lead into the voltage jack. Set the function to AC voltage, marked V with a tilde. Hunker recommends a 240 V range for the first reading. If your meter is auto-ranging, the choice is made for you. Do not place the red lead in a current jack, because that can short the circuit when you measure voltage.
Step 3: Breaker on, dryer still unplugged
Switch the breaker on. Keep the dryer unplugged so that no load is connected while you measure. Place one probe in each slanted hot slot, keeping your fingers behind the probe guards. Read the display, which should show about 240 V. Then remove the probes one at a time. A healthy 240 V circuit reads close to 240 V between the two hot slots.
Step 4: Check each hot leg to neutral and ground
Now measure from each hot slot to the neutral slot, and from each hot slot to the ground slot. On a standard four-prong dryer receptacle, each hot leg should read about 120 V to neutral and about 120 V to ground. Neutral to ground should read close to zero. Kaiweets gives the same pattern for a four-prong 120/240 V outlet. Hunker describes a version of the same check, where each hot slot is measured to the ground slot with the meter on a 120 V range.
Write down each reading before you move the probes. A written log lets you compare the two legs and spot a weak one. A reading that is not close to 120 V on one leg while the other is normal points to a problem on that leg.
Step 5: Read the results
A healthy result looks like this: about 240 V hot to hot, about 120 V on each hot leg to neutral, and about 120 V on each hot leg to ground. The sources we read agree on this pattern. The following results point to specific problems.
- Near zero volts hot to hot usually means the breaker is off, power is lost, or the feed is open.
- About 120 V hot to hot can mean one hot leg is missing, which leaves the dryer with only one live conductor.
- One leg reading near 120 V and the other near zero points to an open or tripped breaker, or a loose connection on the dead leg.
- Readings that move around or change when you wiggle the probe usually mean poor probe contact or a loose terminal.
- Hot-to-hot near 240 V with both legs at about 120 V to neutral means the supply is normal. In that case, a dryer that does not heat is more likely to have a fault inside the appliance, such as a heating element or thermostat.
A reading that looks wrong on one leg but normal on the other is a common source of confusion. A loose neutral can produce odd readings, because the meter reads a voltage between the live conductor and a neutral that is no longer at ground potential. If you see that pattern, do not keep probing the same points. Stop and get the wiring checked.
Safety checks that come first
Keep your hands on the insulated parts of the probes, and do not touch the metal tips while they are connected. Never let the probe tips touch each other, and never test with wet hands or on a wet floor. Stop immediately if you see heat damage, smell burning, or hear arcing. Ask-the-electrician notes that circuit testing and repair are best done by a licensed electrician, and that work on energized circuits carries real risk. Check with your local building department about permits before any repair.
Kaiweets describes 240 V as a three-phase supply. That is not correct for a standard single-phase US dryer circuit, which is a split-phase 240 V supply. Its wire-color and screw-location instructions also do not match a typical dryer receptacle. We did not rely on those parts of the article.
When to call an electrician
Call a licensed electrician if the hot-to-hot reading is not near 240 V, if any leg is off, if the receptacle is hot to the touch, or if the outlet shows burn marks. Also call one if the readings point to the panel or to the wiring behind the wall, since those checks require opening the panel and working on energized conductors. A dryer that will not heat with normal readings at the outlet should be diagnosed by a technician who can test the appliance itself.
Related tests on this site
If your outlet check turns up a receptacle problem beyond the dryer circuit, our guide to the best AC outlet tester covers plug-in testers that show wiring faults quickly. For continuity checks on a cord or a dryer plug, our continuity tester how-to explains the steps. Use those tools as a first pass, then confirm with a meter.
What we could not verify
We did not test a live dryer circuit, so the readings above are the values the sources expect, not measurements we took. The guides we opened do not give a single agreed threshold for an acceptable low reading, so we have not set one. We did not verify local code requirements, breaker sizes or wire gauges for any particular home. Check your local rules and the dryer manual.
How we chose
We used three guides we could open and read on 2026-10-29: a meter-maker blog, an electrician Q and A article, and a general how-to site. We compared their steps and expected readings, and kept the points they agreed on. Where one guide contained an error, we say so in the text and do not follow it. We did not rely on any single source for a safety threshold, and we left out wiring details that only one guide gave.
FAQ
What reading should a 240 volt dryer outlet give?
About 240 V between the two hot slots, and about 120 V from each hot slot to neutral or ground.
Can I test the outlet with the dryer plugged in?
No. Unplug the dryer before you test, so that no load is connected during the measurement.
What does a reading of 120 V hot to hot mean?
It can mean one hot leg is missing, so the outlet is not receiving both legs of the supply.
Which meter setting should I use?
AC voltage, with a range above 250 V on a manual-ranging meter. An auto-ranging meter sets the range itself.
When should I stop and call an electrician?
If the hot-to-hot reading is not near 240 V, a leg is missing, the receptacle is hot or burned, or the wiring behind the wall needs checking.
Sources
- Kaiweets, How to Check 240 Voltage with a Multimeter, opened 2026-10-29: https://kaiweets.com/blogs/news/how-to-check-240-voltage-with-a-multimeter
- Ask the Electrician, Testing a 240 Volt Dryer Circuit, opened 2026-10-29: https://ask-the-electrician.com/testing-a-240-volt-dryer-circuit
- Hunker, How To Test A 240-Volt Circuit, opened 2026-10-29: https://www.hunker.com/13416085/how-to-test-a-240-volt-circuit/
