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frontpageRokket | Staff posted Today 3:50 AM

Klein Tools GFCI Receptacle Outlet Tester w/ LCD

$20

$25

20% off
Amazon
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Deal Details
Amazon has Klein Tools GFCI Outlet Receptacle Tester w/ LCD (RT250) on sale for $19.88. Shipping is free w/ Prime or on $35+ orders

Lowe's also has Klein Tools GFCI Outlet Receptacle Tester w/ LCD (RT250) on sale for $19.98. Shipping is free for My Lowe's Rewards Members (free to join), otherwise select free store pickup where available.
  • Note: Availability for pickup may vary by location.
Thanks to Deal Hunter Rokket for sharing this deal.

Details:
  • GFCI receptacle tester with large backlit LCD readout for voltage and wiring conditions
  • Displays trip time for GFCI devices
  • Detects and identifies common wiring faults
  • Patent-pending Open Neutral and Open Ground detection
  • Auto-Hold feature for hard-to-reach outlets
  • Uses 2 x 1.5V AAA batteries (included)

Editor's Notes

Written by citan359 | Staff

Original Post

Written by Rokket | Staff
Community Notes
About the Poster
Deal Details
Community Notes
About the Poster
Amazon has Klein Tools GFCI Outlet Receptacle Tester w/ LCD (RT250) on sale for $19.88. Shipping is free w/ Prime or on $35+ orders

Lowe's also has Klein Tools GFCI Outlet Receptacle Tester w/ LCD (RT250) on sale for $19.98. Shipping is free for My Lowe's Rewards Members (free to join), otherwise select free store pickup where available.
  • Note: Availability for pickup may vary by location.
Thanks to Deal Hunter Rokket for sharing this deal.

Details:
  • GFCI receptacle tester with large backlit LCD readout for voltage and wiring conditions
  • Displays trip time for GFCI devices
  • Detects and identifies common wiring faults
  • Patent-pending Open Neutral and Open Ground detection
  • Auto-Hold feature for hard-to-reach outlets
  • Uses 2 x 1.5V AAA batteries (included)

Editor's Notes

Written by citan359 | Staff

Original Post

Written by Rokket | Staff

Community Voting

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+54
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8 Comments

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Pro
Today 2:14 PM
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Joined Jun 2006
KO3bIPb
Pro
Today 2:14 PM
5.2K Comments
if you don't care about LCD

$7 harborfreight
https://www.harborfreight.com/ele...63929.html

$7 amazon
https://www.amazon.com/Gardner-Be...B00170KUPC

edit:
$9 and up if you do want lcd because 3-lights code is confusing and scary
https://www.amazon.com/s?k=Recept..._sb_noss_1
:tide
Last edited by KO3bIPb August 3, 2026 at 07:43 AM.
1
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Today 2:20 PM
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CyanTest728Today 2:20 PM
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1
Today 3:12 PM
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hellspiceToday 3:12 PM
952 Comments
Like daddy says, "You won't need it 'til you need it."
Pro
Today 3:32 PM
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Joined Sep 2016
vid1900
Pro
Today 3:32 PM
3.2K Comments

Our community has rated this post as helpful. If you agree, why not thank vid1900

Quote from KO3bIPb :
$9 and up if you do want lcd because 3-lights code is confusing and scary
https://www.amazon.com/s?k=Recept..._sb_noss_1
:tide
The LCD screen is not really for people that find the light sequence difficult to decode.

The screen is to give you the GFCI trip time (older/defective GFCI will often still trip, but take too many milliseconds to do so). After 15 or so years, they may trip with the self-test button, but not with an external tester. That is why the home inspector will flag certain GFCI, even though they appear to 'work'.

The other reason the LCD is useful, is that it will read the voltage at the outlet. This only happened to me once, but a woman told me "Wait! Don't use that outlet! It kills everything you plug into it.". I checked, and the outlet had 244vac available. Someone had connected a different hot to each side of the outlet. I fixed it for her, and then checked all her other outlets, just to be safe. It was the only one; not sure if someone did it on purpose to run a window a/c, or if they were just insane.
4
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Today 4:26 PM
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Joined Apr 2025
DoNotTapeOverToday 4:26 PM
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Thanks!
Today 4:40 PM
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Joined Nov 2015
Straightsix9904Today 4:40 PM
131 Comments
Quote from vid1900 :
The LCD screen is not really for people that find the light sequence difficult to decode.

The screen is to give you the GFCI trip time (older/defective GFCI will often still trip, but take too many milliseconds to do so). After 15 or so years, they may trip with the self-test button, but not with an external tester. That is why the home inspector will flag certain GFCI, even though they appear to 'work'.

The other reason the LCD is useful, is that it will read the voltage at the outlet. This only happened to me once, but a woman told me "Wait! Don't use that outlet! It kills everything you plug into it.". I checked, and the outlet had 244vac available. Someone had connected a different hot to each side of the outlet. I fixed it for her, and then checked all her other outlets, just to be safe. It was the only one; not sure if someone did it on purpose to run a window a/c, or if they were just insane.
This one says it is rated up to 135v. Is that a safety thing since they can't write 220 as the plug was obviously not designed for it? Would it just trip and i have to break out a multimeter to determine the exact voltage on a situation like you described?
Pro
Today 5:28 PM
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vid1900
Pro
Today 5:28 PM
3.2K Comments
Quote from Straightsix9904 :
This one says it is rated up to 135v. Is that a safety thing since they can't write 220 as the plug was obviously not designed for it? Would it just trip and i have to break out a multimeter to determine the exact voltage on a situation like you described?
It illuminates RED to show voltage over 135vac and gives you the ">" symbol next to the voltage.

Of course, then you would probably break out a multimeter and check the voltage from ground to Hot and ground to Neutral. If both read 120vac then you know where you are at.

It also shows if you have less than 30vac, for those times where you have the breaker off, but there is still a small amount of voltage at the outlet. This is usually older homes that still have some knob&tube hidden somewhere, and somebody has "stolen the Neutral" from another branch.
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Today 5:54 PM
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Joined Jun 2006
obtusenessToday 5:54 PM
47 Comments
Quote from vid1900 :
The LCD screen is not really for people that find the light sequence difficult to decode.The screen is to give you the GFCI trip time (older/defective GFCI will often still trip, but take too many milliseconds to do so). After 15 or so years, they may trip with the self-test button, but not with an external tester. That is why the home inspector will flag certain GFCI, even though they appear to 'work'. The other reason the LCD is useful, is that it will read the voltage at the outlet. This only happened to me once, but a woman told me "Wait! Don't use that outlet! It kills everything you plug into it.". I checked, and the outlet had 244vac available. Someone had connected a different hot to each side of the outlet. I fixed it for her, and then checked all her other outlets, just to be safe. It was the only one; not sure if someone did it on purpose to run a window a/c, or if they were just insane.
This is a great point. I worked on a "haunted" outlet once, where some stuff would work ok and other stuff did not. Turned out it was a loose hot, and inserting a plug would sometimes make the connection better or worse. My harbor freight tester said it was ok, but my meter showed it was only pulling around 105v. Pulled the outlet out and saw that when the terminal screw was tightened the loop popped out a bit and it was barely connected. Little things like this are where using better tools can save you time or headache.

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