Smart Toilet Voltage and Grounding for North America

Electrical review is the step that most often delays a smart toilet order — not the ceramic, not the finish, not the freight. A washlet-style unit is a heated appliance sitting inside a wet room, and the destination market decides its supply voltage, its plug, its protection device and the position of the outlet. Getting that wrong is expensive twice: once when the unit will not run, and again when the wall has to be reopened.

This guide covers what to confirm for United States and Canadian projects, using the configurations documented in our own product records. For the full model range, start with the smart toilet category; for retrofit seats, the seat category compares the two formats.

Start from the documented supply, not the region

Voltage is a per-model configuration, not a company-wide setting. The records for our current catalogue read as follows.

Model	Documented supply	Rated power
A17 / A18	110–130V	1,100 W rated / 1,600 W maximum
S21G	AC 110V / 60Hz	See model manual
W1	110V AC ±10%, 50/60Hz	1,260 W (manual) / 1,360 W (parameter graphic)
K1	110V ±10%, 50/60Hz	1,260 W (manual) / 1,350 W (parameter image)
6293	110V AC ±10%, 50/60Hz	1,260 W (manual)
T1 bidet seat	110V AC, US plug	1,200 W
B04 bidet seat	100–130V AC, 50/60Hz	1,260 W rated, ≤1,800 W maximum

Two things in that table matter more than the numbers themselves.

First, the ±10% tolerance on the integrated models means a nominal 120V North American supply sits comfortably inside the working window, while a 220–240V supply does not — there is no site-side workaround, because the heater, pump and control board are all built for the stated range. A step-down transformer is not an acceptable substitute for the correct factory configuration on a project we are asked to support.

Second, the W1 and K1 source packs each list two different rated-power values. We publish both rather than picking the more convenient one. Treat the final electrical rating as a confirmation item at quote stage, especially if your electrical engineer is sizing circuits close to a limit.

Size the circuit for a heater, not for a toilet

An instant-heating unit draws its peak current in short bursts while washing water is heated on demand. At a nominal 120V supply:

• 1,100 W is roughly 9.2 A
• 1,260 W is roughly 10.5 A
• 1,360 W is roughly 11.3 A
• 1,800 W peak is roughly 15 A

A single unit on a dedicated 15 A or 20 A branch circuit is the straightforward answer. What causes trouble is a shared circuit — a bathroom receptacle circuit already carrying a hair dryer, a towel warmer or a second bathroom is where nuisance tripping starts. In multi-unit residential and hotel work, the electrical drawing should show the smart toilet outlet as its own load, and the schedule should note the peak figure rather than the average.

For Canadian projects, remember that the electrical review is a separate exercise from the plumbing review even when both are in the same submittal package.

Grounding, GFCI and the wet-room rules

Every model in the catalogue is built for a grounded three-prong supply. The K1 manual is explicit on two points that apply across the range: install on a grounded 110V supply, and do not use an extension cord. Both instructions exist because the appliance combines mains heating with water.

Bathroom receptacles in the United States are required by the National Electrical Code to be GFCI-protected, and Canadian practice under the CEC is equivalent. This is a long-standing rule, not a new one — GFCI protection has been required in bathrooms since the 1975 edition of the NEC, and the Electrical Safety Foundation International credits it with an 80% drop in electrocutions since then. See the ESFI overview of GFCI protection for the background. Confirm three things with the electrician of record:

1. The receptacle serving the unit is GFCI-protected, and the protection device is accessible for testing.
2. The receptacle is grounded and tested — not simply a three-slot face on an ungrounded circuit, which is a common finding in older housing stock.
3. The outlet is outside the direct splash zone but within cord reach.

On the product side, the units carry their own protection layers: leakage protection, temperature sensing and high-temperature cut-off appear in the K1 and W1 material, IPX4 water protection is documented on 7 of the 11 current models, and the T1 seat uses a 12V safety voltage on its low-voltage side with flame-retardant housing material.

Cord length decides the outlet position

This is the detail that gets missed on drawings and discovered on site. Documented cord lengths:

• S21G: approximately 1 m (39.37 in)
• A17 / A18: approximately 1.2 m (48 in)
• W1 and K1: 1.5 m
• T1 seat installation guide: socket within approximately 1.5 m, water inlet valve within approximately 0.5 m

A 1 m cord on a unit whose inlet is at the left rear does not reach an outlet placed by habit on the opposite wall. For new construction, fix the outlet position in the rough-in drawing beside the drain and the angle valve. For retrofits, photograph the existing outlet and valve positions with a tape measure in frame before the order is approved — that single photo resolves most later disputes.

50 Hz, 60 Hz and mixed-market orders

Most of the range is documented at 50/60Hz, which simplifies orders that span markets. The S21G, however, is documented specifically at 60Hz. If one purchase order serves both a North American and a 50 Hz market, split the electrical configuration by destination in the order lines rather than assuming a single SKU covers both, and ask us to confirm the plug type and certified electrical version per destination.

The electrical review checklist

Send these five items with your enquiry and we can complete an electrical review in one pass rather than three:

1. Destination market and nominal supply voltage.
2. Whether the circuit is dedicated, and its breaker rating.
3. GFCI protection method — receptacle or breaker.
4. Outlet position relative to the drain, with the distance to the angle valve.
5. Quantity per configuration, so the correct plug and certified electrical version is quoted per line.

For unit-level electrical data, the K1 and W1 records publish the full parameter tables, and the T1 and B04 seat records include their installation environment requirements. Manuals for those models are in technical downloads. The related rough-in and compliance guides — 300 mm vs 400 mm and how cUPC, WaterSense, UL and FCC differ — cover the plumbing and listing side of the same approval file.

If the site conditions are unusual — an ungrounded circuit, a shared bathroom circuit at capacity, or a market whose plug standard is not in the list above — send the details to our technical team with photos, and we will confirm what can be configured before anything is quoted.