Recently a plumber installed a VIQUA IHS12-D4 Whole Home Integrated UV Water Treatment at our cottage. It plugs into a standard wall electrical socket with a 3-prong plug. The socket and panel are modern and inspected.

The manufacturer Owner's Manual (link on above web page under Resources) says

  • “For safety reasons the outlet must be protected by a GFCI”
  • “To protect the controller, a UL1449 certified transient voltage surge suppressor is required”

I asked the plumber who said "No it is not required as the unit is grounded."

Is the plumber correct so no further action is required?

In the area we regularly have power outages due to Hydro Quebec distribution grid problems, and occasionally have thunderstorms with lightening, hence risk of voltage surge.

Or should I install a GFCI electrical socket (or circuit breaker which is generally more expensive)?

And then how to add a surge suppressor? There are circuit breakers with a built-in surge suppressor for > $200 but they don't seem to be GFCI, or I could plug a $50 surge suppressor power bar into the socket (GFCI) and then the water filter into the power bar.

But the latter seems dodgy in a utility room with so much water and electricity close together, water supply, filter, pressure tank and hot water tank.

Thanks in advance for your thoughts.

  • 4
    The plumber is half right if the socket was installed before code changed to require GFCI to be used. You are not required to add GFCI protection, but it is recommended. Power surges can damage most electronics, so plug in surge protectors and/or whole house surge protectors are recommended. Not using a GFCI and surge protector mentioned in the instructions will cause warranty being denied , so you will have to pay out of pocket.
    – crip659
    Jul 22, 2023 at 11:22

3 Answers 3


The GFCI and the surge protector provide different types of protection against different problems and that's why the instructions call for both types of protection for this device.

The GFCI protect you from electrocution. "in a utility room with so much water and electricity close together" is exactly what the GFCI protects against. Should there be any wiring fault, the GFCI will turn off power long before a breaker trips. Due to the way breakers are designed to work, the breaker might not trip until long after enough electricity has flowed through your body to kill you.

The surge suppressor protects your electronic devices from overcurrent (or excess amperage). Often times, especially where the power supply isn't particularly stable and/or you get a lot of electrical storms, you will get significantly more than nominal line voltage or amperage coming out of your outlets. While some basic appliances (an older refrigerator or oven for example) won't mind a few hundred extra volts for a very brief time, anything with a computer in it (like your water treatment system, desktop/laptop computer, fancy new fridge, stove with digital timers, etc.) won't take well to that at all. Too many (or sometimes, just one) surges will let all the magic smoke out of these devices and they'll stop working.

When that happens, you'll rue the decision to save $200 (or less) on the surge suppression, as you spend thousands replacing appliances including your new water treatment system.


The plumber is not an electrician, and not the person that will be paying for the warranty denied repairs unless you can drag them to small claims court and win.

I would assume that CEC is similar to NEC in requiring that you follow manufacturer instructions, and you'll definitely void your warranty by not doing so.

While costs are off-topic, your plug-in surge suppressor price seems terribly high. I would replace the receptacle with a GFCI receptacle, and plug in a single-port surge suppressor, unless you need to protect other things in the same room. Those have no cord, just prongs on the back and a receptacle on the front, so they plug in and the cord plugs into them.

Your concern about "so much water and electricity close together" is, in fact, covered by the GFCI.

Current NEC code (I don't know if CEC has the same) now requires whole-house surge suppression (i.e. a big one in the main electrical panel.) That requirement has made them much easier to find - again, you might want to shop more for a better price than you found. I would consider retrofitting one there given mention of frequent outages and lightning surges, but I would still put an individual suppressor on on the receptacle for this device.

  • 1
    Unless one surge strip will power all of your electronics, by the time you add them all up, the whole house ones come to almost the same price.
    – crip659
    Jul 22, 2023 at 13:54
  • @crip659: sometimes true, though installation costs may make it less so. However, the whole house ones generally are warranted only for damage to the house and it's permanent systems; if you want at least some hope that the surge protector's manufacturer will help repair your home entertainment system, you may want the protected power strip instead, or (my current setup) as well.
    – keshlam
    Jul 22, 2023 at 15:15

NEC 110.3: Follow labeling and instructions

Equipment is required to be built to certain standards, and the design approved by an independent 3rd party testing lab (NRTL) and put on a list of approved items (Listed, e.g. UL Listed). For example UL or CSA are the curators of the standards for the US and Canada.

The NRTL approves the instructions as part of approving the device, and only certifies them as safe when those are followed.

But that only matters if it is on the labeling and instructions as approved by UL or other NRTL.
For a water handling appliance, obviously, it seems perfectly reasonable for an NRTL to say "we cannot guarantee the safety of this equipment if it's not GFCI protected".

As for the surge suppressor, I don't know. It might not be on the UL instruction sheet and may simply be a requirement for the warranty. UL 1449 specifies the standard the surge suppressor must meet. Lots of very junky products call themselves "surge suppressors".

Note that in NEC 2020, NEC 230.67 was added and requires surge suppression in the main panel for new construction and remodels.

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