How to Install a TOTO WASHLET in Canada: Step-by-Step Guide (2026)

Prices in CAD as of September 29, 2026, from plumbingmarket.ca. Prices and stock can change, so the product page always has the current number.

A TOTO WASHLET is one of the easier bathroom upgrades you can do yourself. There's no cutting, no new drain and no wax ring. The seat bolts onto your existing toilet, takes water from the toilet's own supply through a T-connector, and plugs into an outlet. Most of the questions we get are about the parts around it: does the outlet need to be GFCI, how far can it be from the toilet, what's the T-connector for, and why is it leaking?

This guide walks through the full installation using only TOTO's own instructions (the TOTO USA installation guide, plus the installation manuals, owner's manuals and spec drawings on totousa.com). It covers the steps, the electrical requirements for each model, fit on round and elongated bowls, and troubleshooting, with notes for Canadian homes. If you haven't chosen a seat yet, start with our WASHLET S2 vs S5 vs S7 vs S7A comparison or guide to the C5 replacement (C5 vs S5).

Jump to: Before you start · Fit · Step-by-step · WASHLET+ · Aquia adaptor · Auto flush · Electrical · Water pressure · Removal · Troubleshooting · Warranty · FAQ

Before you start: tools, parts and checks

Tools

TOTO's installation guide lists just two tools:

• An adjustable wrench, for the supply line and a brass T-connector
• A Phillips screwdriver, for the base plate

A towel, a small bucket or sponge (the supply line holds some water) and a flashlight for behind the toilet also help. TOTO's manuals note that each seat is water-tested at the factory, so a little water may drip out of a new seat. That's normal.

What's in the box

• Base plate with bolts and compression sleeves for the seat-mounting holes
• T-connector (TOTO also calls it a junction valve), brass or plastic depending on the model
• Water supply hose from the T-connector to the seat
• Remote and wall holder on remote-controlled models (S5, S7, S7A). The S2 has side-arm controls instead

Use the supplied parts. TOTO's installation manuals say not to use water supply hoses or junction valves other than those supplied with the product. You keep your existing toilet supply line, which reconnects to the bottom of the T-connector. If it no longer reaches after the T-connector is added, TOTO's guide says TOTO provides an extension adapter.

Checks before you buy or install

Will it fit? Round vs elongated

Match the seat to the bowl first. Measure from the centre of the seat bolts to the front edge of the bowl, or check your toilet's model number. TOTO makes most WASHLET models in both round and elongated versions, and you order the one that matches your bowl.

Then check the clearance behind the bolts. TOTO's fit guidance says an elongated toilet needs at least 2" from the front of the tank to the centre of the mounting holes, and TOTO's WASHLET fit chart lists the same 2" minimum for round-front bowls on the S2, S5, S7 and S7A. On a one-piece toilet or a tank that sits close to the bowl, measure this before ordering. TOTO also warns that some seats "may not fit certain toilet bowl designs" and asks for your toilet model number with the order.

For the full list of TOTO toilets that take a WASHLET, see which TOTO toilets are WASHLET compatible. If you're replacing the toilet as well, the Drake elongated ($419.99), Drake round ($345), UltraMax round ($733) and UltraMax elongated ($607) all take a standard WASHLET. Our Drake vs Aquia IV vs UltraMax guide compares them.

Step-by-step: how to install a TOTO WASHLET

These are TOTO's steps from its installation guide and the S5/S2 installation manual. They apply to standard WASHLET seats (S2, S5, S7, S7A) on a two-piece or one-piece toilet. Your seat's installation manual is the final word on part numbers and torque, so keep it handy.

Step 1: Turn off the water and empty the tank

Close the toilet's shut-off valve and flush to empty the tank and relieve the pressure in the line.

Step 2: Disconnect the toilet supply line

Unscrew the supply line from the bottom of the toilet tank. Keep a container or sponge underneath to catch the water left in the line.

Step 3: Attach the T-connector

Screw the T-connector supplied with your WASHLET onto the tank's fill-valve inlet, where the supply line was connected. A brass T-connector can be snugged gently with a wrench; a plastic one is hand-tight only.

Tip: the T-connector goes on the tank side of the supply line, at the fill-valve inlet under the tank, where TOTO says the water line connected at the base of the toilet.

Step 4: Reconnect the supply line to the T-connector

Connect the toilet supply line to the bottom of the T-connector. Check that the rubber cone washer is seated in the thumb nut. If the line no longer reaches, use the extension adapter TOTO provides.

Step 5: Remove the old seat

Unbolt and lift off the old toilet seat, then clean the bowl around the mounting holes.

Step 6: Position the WASHLET

Rest the WASHLET on the bowl to check the fit. On a standard toilet the power cord and hose sit outside the bowl. On a WASHLET+ toilet, feed them into the hole on the far left of the mounting surface.

Step 7: Install the base plate

Insert the compression sleeves into the seat-mounting holes. Set the base plate so its adjustment tabs match your hole spacing, centre it with the back closest to the tank, and tighten the bolts so the plate is snug but can still slide.

TOTO uses two base plate styles, with metal or plastic adjustment tabs. The arrows on the tabs point outward or inward depending on the spacing of your toilet's holes, as shown in your manual. The S5/S2 manual warns that if the base plate screws aren't fully tightened, the seat can shift sideways.

Step 8: Slide the WASHLET onto the base plate

Slide the seat forward onto the base plate until it clicks, and pull gently to confirm it's locked. To adjust, press the release button on the side, slide the seat off, realign the plate and tighten it fully.

TOTO's S5/S2 manual says to push the seat on until you hear a click, then check it can't be removed when pulled. A seat that isn't locked on may show a flashing Power light.

Step 9: Connect the seat hose

Connect the WASHLET water hose to the side outlet of the T-connector. Tighten the nut by hand only and make sure the hose isn't kinked.

Step 10: Turn the water on

Open the shut-off valve slowly and check every connection for drips. Let the tank refill.

Step 11: Plug in the seat

Plug the power cord into a grounded 120 V GFCI outlet within reach of the cord. Don't use an extension cord or multi-outlet adapter.

Step 12: Set up the remote

If your model has a remote, insert the batteries, turn it on and choose your settings. Hold the remote where you plan to mount it and check the seat responds before you fix the wall holder.

TOTO's manuals note that the remote's signal depends on where it sits, the size of the room and the wall colour, so test the position before drilling for the holder.

Step 13: Test the seat

Press the seat down (TOTO suggests around the 10 o'clock position) to activate the seat sensor, press rear wash while catching the spray in your hand, then press Stop. Check the connections for leaks one more time.

That's it. For care after installation, see how to clean your TOTO WASHLET. If anything doesn't work, the troubleshooting table below comes from TOTO's owner's manuals.

Shop S5 Elongated – $955 Shop S5 Round – $955 Shop S2 Round – $781.20

WASHLET+ toilets: what changes

A WASHLET+ toilet has a hole in the mounting surface so the seat's hose and cord can run inside the toilet, out of sight. The steps are the same, with one change at step 6: TOTO's guide says to feed the power cord and hose into the hole on the far left of the mounting surface. On a standard WASHLET they rest outside the bowl.

• TOTO's S5 Elongated spec sheet says the S5 works on both WASHLET+ and non-WASHLET+ toilets.
• TOTO's fit chart marks which WASHLET seats are compatible with both traditional and WASHLET+ toilets. Check the seat's own spec sheet before routing its hose and cord through the hole.
• For a fully hidden hookup on a new toilet, a WASHLET+ set such as the Drake WASHLET+ S5 ($1,448) or UltraMax WASHLET+ S5 ($1,561) comes with a matched toilet and seat.

Our WASHLET+ vs WASHLET guide covers the WASHLET+ sets and their connections in detail.

Aquia IV owners: the 9AU321-A adaptor

TOTO's spec sheet for the Aquia IV two-piece ($769.99) lists the 9AU321-A WASHLET adaptor as "Required for WASHLET installation". Buy the 9AU321-A adaptor ($14.40) with the seat if you have an Aquia. Only the Aquia needs it. Drake and UltraMax toilets don't, and neither do most non-TOTO toilets. Follow the adaptor's own instructions for where it fits in the installation.

Auto flush kit (S7 and S7A on elongated bowls)

The WASHLET S7 and S7A can flush the toilet automatically when you stand up, using TOTO's THU857 auto flush kit ($195.84). The THU857 fits elongated bowls only, so it isn't an option on a round toilet, and it only works with the S7 and S7A (not the S2 or S5). TOTO lists the THU857 in its Drake and UltraMax WASHLET+ S7/S7A sets, and a THU855 kit for the Aquia IV WASHLET+ S7A. Install the seat first, then follow the kit's instructions.

For auto flush, pair the kit with the S7A Elongated ($1,966) on an elongated toilet such as the Drake elongated.

Shop THU857 kit – $195.84 Shop S7A Elongated – $1,966

Electrical requirements

This is the part that sends most people to an electrician. TOTO's installation page puts it plainly: "Electrical code requires a ground fault 120 volt outlet for bathroom appliances, and one needs to be within reach of the three-foot WASHLET cord."

Outlet and amperage by model

From the notes on TOTO's spec drawings:

The S-series seats draw about 1,270–1,295 W because they heat water on demand instead of keeping a small tank warm, as the replaced C-series seats did. Our C5 replacement guide (C5 vs S5) explains the difference.

TOTO's electrical rules

• Grounded, GFCI-protected outlet. TOTO's installation guide calls for a grounded (3-prong) outlet on a ground fault circuit interrupter (30 mA or less), and the S5/S2 manual says to check that a ground is installed.
• Within cord reach. The cord is about 3.9 ft (1.2 m), and TOTO says to check the outlet is in a suitable spot for that length.
• No extension cords or multi-outlet adapters. TOTO warns against exceeding the rated capacity of the outlet or wiring.
• Not directly under the water supply. TOTO says not to install the outlet directly beneath a water supply, and not to let the water hose touch the outlet or plug, because condensation can cause a fire or shock.
• Surge protection is "highly recommended" on TOTO's spec sheets, and the warranty excludes surge damage.

Adding an outlet in Canada: permits

If there's no outlet near the toilet, adding one is electrical work, and permit and inspection rules depend on your province and municipality. Before you start, check with your local electrical authority, such as the Electrical Safety Authority (ESA) in Ontario. A licensed electrician will know what applies where you live. If the bathroom circuit also feeds a hair dryer or space heater, ask them about capacity too, especially for an S-series seat.

Water pressure and supply

• Pressure: 7.25 psi minimum and 108.75 psi maximum (static) on TOTO's spec sheets. TOTO's warranty notes that plumbing codes allow a maximum of 80 psi, and it doesn't cover pressure above local codes. If your home pressure is high, a pressure-reducing valve protects the seat.
• Water: potable (drinking) water only. TOTO says not to use recycled water.
• Temperature: TOTO's installation guide gives a supply-water range of 32–95 °F (0–35 °C) and a room range of 32–104 °F (0–40 °C). The seat isn't designed for rooms that can freeze, such as an unheated cottage bathroom, unless it's drained first (see below).

Removing a WASHLET

You'll need to remove the seat to deep-clean around it, move house or switch back to a regular seat. It's the installation in reverse:

1. Unplug the seat and close the shut-off valve.
2. Press the release button on the side of the seat and slide it forward off the base plate.
3. Disconnect the WASHLET hose from the T-connector, with a container underneath.
4. Unbolt the base plate.
5. To go back to a regular seat, remove the T-connector and reconnect the supply line straight to the tank.

Long periods without use or freezing risk: TOTO's manuals say to turn off the breaker or unplug the seat and take the batteries out of the remote. If the room may freeze, drain the seat as described in your owner's manual.

Troubleshooting a new installation

From the troubleshooting sections of TOTO's S5 owner's manual. Check your own model's manual for its exact lights and buttons.

If water leaks at any point, close the shut-off valve first. TOTO's US support line listed on its installation guide is 888-295-8134 (ext. 4). If your GFCI keeps tripping, unplug the seat and have the outlet and circuit checked before using it again. Questions about a seat you bought from us? Call our Vaughan showroom at 289-236-2378.

Warranty: installation matters

• Term: the S2 and S5 spec sheets list a One Year Limited Warranty. The S7 and S7A list Two Year Limited (residential).
• Coverage (S5 owner's manual): defects in materials and workmanship when properly installed and serviced, for the original purchaser, on products bought and installed in the USA and Canada. Proof of purchase is required.
• Exclusions that relate to installation: improper installation, not using a 120 V, 60 Hz GFI outlet, electrical surges, water pressure above local codes, and sediment or water quality. TOTO doesn't cover the cost of removing or reinstalling the seat.

Keep your receipt and the installation manual, and follow the GFCI and pressure requirements above.

Which seat is easiest to install?

They all install the same way, so choose on features and your electrical setup:

• Wireless remote: S5 Elongated ($955) or S5 Round ($955). Instantaneous warm water and a wireless remote. Needs a 15 A GFCI outlet.
• Budget with continuous warm water: S2 Elongated ($590) or S2 Round ($781.20), with side-arm controls, so there's no remote holder to mount.
• Auto flush: S7A Elongated ($1,966) with the THU857 kit.
• New toilet with hidden hookups: Drake WASHLET+ S5 ($1,448).

Not sure what fits? Call our Vaughan showroom at 289-236-2378 or email sales@plumbingmarket.ca with your toilet model number. TOTO WASHLET seats ship free across Canada, and other orders ship free over $900.

Related: TOTO WASHLET+ vs WASHLET · TOTO WASHLET S2 vs S5 vs S7 vs S7A · TOTO WASHLET C5 replacement: C5 vs S5 · TOTO Drake vs Aquia IV vs UltraMax · Which TOTO toilets are WASHLET compatible? · How to clean your TOTO WASHLET · All TOTO WASHLET bidet seats

FAQ

How do I install a TOTO WASHLET myself?

TOTO presents it as a DIY job with an adjustable wrench and a Phillips screwdriver. Turn off the water and flush, fit the supplied T-connector between the supply line and the tank, remove the old seat, bolt on the base plate, slide the WASHLET on until it clicks, connect its hose to the T-connector, turn the water back on and plug the seat into a grounded GFCI outlet. The only part that may need a professional is the outlet, if you don't already have one near the toilet.

What tools do I need to install a TOTO WASHLET?

TOTO lists an adjustable wrench and a Phillips screwdriver. Add a towel or small container for the water left in the supply line. The T-connector, water hose and base plate come in the box, and TOTO's manuals say to use only the hoses and junction valve supplied with the seat.

What kind of outlet does a TOTO WASHLET need?

A grounded (3-prong) 120 V outlet protected by a GFCI, within reach of the power cord. The spec sheets list cords of about 3.9 ft (1.2 m), and TOTO's installation page says the outlet needs to be within reach of the three-foot cord. The S2, S5, S7 and S7A drawings note a "GFCI outlet of 120V, 15amps". TOTO's installation guide asks for wiring rated 15 A or more.

Where should the outlet be for a TOTO WASHLET?

Near the toilet and within cord reach, usually on the wall beside or behind the tank. TOTO's installation guide says not to put the outlet directly beneath the water supply, because condensation can get into it, and not to let the water hose touch the outlet or plug. For WASHLET+ toilets, TOTO's set drawings show the outlet 12" above the finished floor.

Do I need a permit or an electrician to add an outlet for a WASHLET?

Installing the seat itself is plumbing-and-plug work. Adding or moving an outlet is electrical work, and the rules depend on your province and municipality. Check with your local electrical authority before you start (in Ontario, that's the Electrical Safety Authority, the ESA). A licensed electrician will know the local requirements.

Does a TOTO WASHLET need a dedicated circuit?

TOTO doesn't say "dedicated circuit". Its manuals ask for a GFCI outlet rated 15 A or more at 120 V, and warn not to exceed the rated capacity of the outlet or wiring. The S-series seats draw about 1,270–1,295 W because they heat water on demand, so ask your electrician whether the bathroom circuit also feeds a hair dryer or heater.

What is the T-connector on a TOTO WASHLET?

The T-connector (TOTO also calls it a junction valve or T-valve) splits the toilet's water supply. It screws onto the tank's fill-valve inlet, the toilet supply line connects to its bottom, and the WASHLET hose connects to its side outlet. It comes with the seat. TOTO's manuals say not to use hoses or junction valves other than those supplied.

Why is my TOTO WASHLET leaking at the T-connector or hose?

TOTO's troubleshooting says to retighten the plumbing connections by hand, without tools. Plastic connectors are hand-tight only, and over-tightening can damage them. Check the rubber cone washer is seated in the supply line's thumb nut. If it still leaks, close the shut-off valve and contact TOTO support.

How do I reset a TOTO WASHLET?

TOTO's S5 manual gives a power reset for some faults, such as the wand not coming out after a drop in water pressure: turn the power off, wait about 10 seconds and turn it on again. If the Power light is flashing, the main unit isn't properly mounted on the base plate; remove it and slide it back on until it clicks. After a power outage, check the breaker and the GFCI outlet.

Do I need an adapter to install a WASHLET on a TOTO Aquia?

Yes. TOTO's Aquia IV spec sheet lists the 9AU321-A WASHLET adaptor as "Required for WASHLET installation". Drake and UltraMax toilets don't need it.

Will a TOTO WASHLET fit my toilet?

Match the seat shape to the bowl: round for round, elongated for elongated. TOTO's fit guidance says an elongated toilet needs at least 2" from the front of the tank to the centre of the mounting holes, and TOTO's fit chart lists the same 2" minimum for round-front bowls on the S2, S5, S7 and S7A. Our compatibility guide lists the TOTO toilets that take a WASHLET, or you can send us your toilet model number.

How do I remove a TOTO WASHLET?

Unplug the seat and close the shut-off valve. Press the release button on the side of the seat and slide it forward off the base plate. Disconnect the hose from the T-connector with a container underneath, then unbolt the base plate. To put a regular seat back, remove the T-connector and reconnect the supply line straight to the tank.

Can I install a WASHLET on a non-TOTO toilet?

Often, yes, if the shape matches and the tank-to-hole clearance meets TOTO's minimums. TOTO notes that some models may not fit certain bowl designs, so check the spec drawing for your seat against your toilet. A WASHLET+ seat only works on a WASHLET+ toilet.

Do TOTO WASHLET seats ship free in Canada?

Yes. TOTO WASHLET seats ship free across Canada from Plumbing Market. Other orders ship free over $900.