An outlet that stops working — or one that looks a bit charred around the slots — usually gets replaced before it gets tested. That is a mistake. A $30 multimeter tells you in under a minute whether the outlet is live, correctly wired, and safe to use, and this Ontario-focused guide walks you through the exact readings a licensed electrician would look for.
Set your multimeter to AC voltage (V~) at 200 V range or higher. Insert the black probe into the neutral (larger slot) and the red probe into the hot (smaller slot) — you should read between 114 V and 126 V. Then test hot-to-ground and neutral-to-ground to confirm polarity and grounding.
If any reading is missing, low, or reversed, the outlet is faulty or wired incorrectly under the Ontario Electrical Safety Code (OESC), 28th Edition.
Testing an outlet is safer than most people think, provided you use the right gear. Cheap multimeters can still deliver accurate readings, but they should carry a CAT II 300 V or better safety rating for household work.
Never test with a cracked probe or damaged lead. According to ESA safety guidance, most electrical shocks in Ontario homes involve worn or improvised tools rather than defective wiring.
Turn the dial to V~ (AC voltage), not V= (DC). If your meter is manual-ranging, choose 200 V. Plug the red lead into the “VΩmA” port and the black lead into “COM.”
Confirm the meter works by touching the probes together — the display should stay near 0.0 V. A wildly jumping reading means dead batteries or a bad probe.
Insert the black probe into the wider (neutral) slot on the left and the red probe into the narrower (hot) slot on the right. A healthy Ontario outlet reads ~120 V AC, with the OESC allowing a working range of 114 V to 126 V (±5%).
Readings under 108 V signal a loose neutral, a shared-neutral overload, or utility service problems. Readings over 126 V can damage electronics and should trigger a call to your Local Distribution Company (LDC) — Toronto Hydro, Alectra, Hydro One, and so on.
Move the black probe from the neutral slot to the round grounding hole below. You should again read close to 120 V. This confirms the ground path is intact and bonded back to the panel neutral.
Zero volts here means the outlet is missing a ground — common in older Toronto homes with two-prong receptacles or knob-and-tube wiring.
Now measure between the neutral (left) and ground (bottom). You should read near 0 V, ideally under 2 V. A higher reading (5 V or more) usually points to a shared-neutral overload or a bootleg ground — a wiring shortcut that hides a missing ground and violates OESC Rule 10-208.
If you read ~120 V between the neutral slot and the ground hole (and 0 V from the hot slot to ground), the outlet is wired in reverse polarity. This is a shock hazard and must be corrected before an ESA inspection will pass.
GFCI outlets test the same way, with one extra step: press “TEST” on the outlet after you finish. The reset button should pop out and readings should drop to 0 V. If they do not, the GFCI has failed and should be replaced — industry data shows GFCI receptacles last on average 10–15 years.
Multimeter readings tell you what is wrong, not why. If your outlet reads outside 114–126 V, shows an open ground, or drops voltage under load, the wiring or panel needs a licensed diagnostic.
EZ Smart Electric (ESA Licence #7012690) offers same-week outlet diagnostics and full electrical repairs across Toronto and the GTA. Call 416-838-9006 or book online through our contact page.
Yes — voltage testing is a live test by design. Just use insulated probes, keep one hand behind your back, and never touch the metal probe tips.
Standard 15-amp residential outlets in Ontario should read between 114 V and 126 V AC (nominal 120 V). Utility supply outside this window is a Local Distribution Company issue.
Compare hot-to-neutral and hot-to-ground readings. If both are within 2 V of each other and near 120 V, the ground is intact. A large difference points to a missing or high-impedance ground.