GFCIs and Tankless Water Heaters: What the 2023 NEC Actually Requires

A Simple Question With a Lot of Confusion Behind It

In a recent Let’s Ask Paul session, Paul Abernathy of Electrical Code Academy tackled a question that comes up constantly in the field: does a tankless water heater require GFCI protection? The short answer is no — but the reasoning behind that answer reveals just how much misunderstanding surrounds ground-fault circuit interrupter requirements, especially with all the expansion in the 2023 NEC.

If you’ve ever found yourself arguing about GFCIs on a job site (or, as Paul jokes, getting into debates on TikTok), this one’s for you.

The 2023 NEC Expanded GFCI Protection — A Lot

Before getting to water heaters, it’s worth understanding just how far GFCI requirements have grown. As Paul puts it:

“In the 2023 NEC we have a lot of expansion of GFCI protection.”

Two changes stand out:

• Section 210.8(D) now extends GFCI protection to specific appliances — including ranges, ovens, microwaves, and cooktops.
• Kitchen receptacles got a major expansion. Previously, only receptacles serving the countertop or within 6 feet of the top inside edge of the sink needed protection. Now, all 125-volt through 250-volt receptacles located in a kitchen must be GFCI protected.

Like it or not, that’s the reality you’ll be working with under the 2023 code.

Killing the “GFCI Is All About Water” Myth

The most useful takeaway from the session is conceptual. Many electricians assume GFCI protection exists wherever there’s water. Paul pushes back hard on that idea:

“If it was all about water and that’s what people say, then why would it now be on ranges and cooktops and microwaves? Think about it, folks.”

It’s a fair point. A properly wired range has nothing to do with water, yet it’s now on the list. Water proximity often correlates with GFCI requirements — sinks, unfinished basements, outdoor locations — but it isn’t the underlying reason. The reason is the risk of a ground-fault path through a person.

Paul’s practical philosophy for electricians is refreshingly direct:

“GFCI is where the code tells us we have to install it. GFCI is where the manufacturer tells us we have to install it on their product.”

Remember that a manufacturer can always be more restrictive than the NEC, but never less. If a product’s listing demands GFCI protection, you follow it — even if the code is silent.

So, Does a Tankless Water Heater Need GFCI?

Here’s the direct answer: a hard-wired tankless water heater does not require GFCI protection anywhere in the NEC.

Why? Because GFCI requirements flow from specific rules, and a tankless unit doesn’t fall under any of them:

1. It is not listed among the appliances in 210.8(D).
2. It is not in the appliance list in Article 422 (specifically 422.5), which covers appliances requiring GFCI protection across both residential and commercial settings — dishwashers being the classic example.
3. Because it’s hard-wired, the receptacle-based rules of 210.8(A) and 210.8(B) don’t apply to it.

The only caveat: if a particular tankless unit happens to be listed for cord-and-plug connection and gets installed via a receptacle in a 210.8(A) or (B) location, then that receptacle would need protection. But for the standard hard-wired install, there’s no requirement.

Paul also notes a practical reality — many whole-house tankless heaters are large enough to require two double-pole breakers, which makes GFCI protection impractical and expensive even if someone wanted to add it voluntarily.

”But There’s Water Circulating Inside It!”

This is where people’s minds go, and Paul addresses it head-on. Yes, water circulates through a tankless heater. So what? The same logic would mean a traditional storage-tank water heater needs GFCI protection — and it doesn’t. The code simply doesn’t require it.

“Remember, you can go above code if you want… if you want to do something just because you feel warm and fuzzy about it, then you do that.”

You’re always free to exceed the code. But it’s not a requirement, and given how much people already grumble about adding GFCIs, few will do it voluntarily.

What About Swimming Pools and Article 680?

A natural objection: isn’t Article 680 (swimming pools) all about water? Paul uses this to teach an important structural lesson about how the NEC works.

The general requirements in Chapters 1 through 4 apply broadly, but they are supplemented and modified by the special rules in Chapter 6 (which includes Article 680). Pools are governed by Code-Making Panel 17, with their own distinct rules. The reason GFCIs are so prolific around pools isn’t simply “water” — it’s about differences of potential:

“When it comes to pools, we’re really trying to establish differences of potential, and the best way to detect that is with a GFCI device.”

A GFCI works by sensing an imbalance between current going out and coming back through the toroidal coil. When current escapes that loop — as it can across an equipotential plane with voltage differences — the device trips. That makes it the most logical protection for that specific hazard. It’s a different problem than the one a kitchen receptacle addresses.

Receptacles vs. Outlets vs. Appliances — Know the Difference

One of the sharpest points in the session is about terminology, because the NEC uses these words precisely:

• 210.8(A) and (B) deal specifically with receptacles in defined locations.
• Once you move beyond those subsections, the focus shifts to outlets and specific appliances.

Paul gives the example of a gas water heater with forced air that needs a receptacle nearby. People argue “it’s a water heater, so it needs GFCI!” — but they’ve lost the plot:

“That’s a receptacle that is installed there to facilitate the forced air. Forget about the water heater — it’s the receptacle that’s in a specific location that may require GFCI protection.”

The trigger is the receptacle and its location, not the appliance behind it. An outlet, by contrast, is simply any point in the system where you can take power — including a junction box that hard-wires directly to an appliance. The appliance lists in 210.8(D) and 422.5 are essentially a shortcut: a no-brainer way to say “this circuit must be protected” without making you parse the outlet definitions every time.

The Code Is an Evolving, Engaged Process

Paul closes with a reminder that the NEC isn’t handed down by faceless bureaucrats or, as he puts it, written by Martha Stewart. Public inputs come from electrical professionals in the field. Interestingly, Code-Making Panel 17 did not accept the expansion of ranges, ovens, and cooktops into 422.5, citing compatibility issues — while Code-Making Panel 2 went ahead and expanded GFCI coverage in 210.8(D). The disagreement is part of the process, and public comments may still shift things:

“Relax — it’s an ongoing, evolving process. The code is a beautiful thing. It is a melding of many minds.”

If you want to change a requirement — like getting tankless heaters added or removed from a list — the path is to engage with the code development process and submit a public input, not just argue about it on the job.

How NEC Mastery Fits Into This

Questions like “does a tankless water heater need GFCI?” are exactly the kind of nuanced, section-specific reasoning that trips people up on exams — and on the job. NEC Mastery is built to train that reasoning:

• 8,000+ exam-style questions drill the real distinctions — receptacle vs. outlet vs. appliance, and which locations in 210.8 trigger protection — so the rules become second nature.
• Detailed explanations referencing specific NEC articles like 210.8(D), 422.5, and 680 help you build a mental map of where these requirements live and why they exist, instead of memorising disconnected facts.
• Timed mock exams weighted to your exam type let you practise navigating these expanded 2023 GFCI rules under pressure, so you can find the right answer fast and walk into your exam with confidence.

The code keeps evolving — make sure your understanding keeps pace.